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Light Electric Vehicle: One-Passenger @ 15mph, 210# Curb
Weightby shastalore on May 8, 2009
Table of Contents
Light Electric Vehicle: One-Passenger @ 15mph, 210# Curb Weight
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Intro: Light Electric Vehicle: One-Passenger @ 15mph, 210# Curb
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Step 1: Unorthodox Treatment for High Rate Sealed Lead Acid
Batteries: . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Step 2: PowerCheq Electronic Battery String Equalizers Increase
the Mileage of the Battery Pack By 75 Percent! . . . . . . . . . .
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Step 3: 24V 40AH LifePO4 Battery Pack! . . . . . . . . . . . . .
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Step 4: Modifying the rake angle of the original HCF-305: . . .
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http://www.instructables.com/id/Light-Electric-Vehicle-One-Passenger-14mph-21/
Author:shastalore Light Electric VehicleBachelor of Science
DegreeIndustrial ArtsAppalachian State UniversityRecession has
dried up my field (commercial printing & packaging), but have
found new work in staging, lighting, sound systems, sets,
productions andevents.
Intro: Light Electric Vehicle: One-Passenger @ 15mph, 210# Curb
WeightI designed and built this fun and successful light electric
vehicle several years ago. I'm just now posting it on
"Instructables" and will add more steps, detailing theconstruction,
in the next few weeks.
Use the link to my webspace, for the details, for the time
being:
www.home.earthlink.net/~hcf-305userforum
I decided to build an electric vehicle from off-the-shelf
components, using existing technology. The goal was to define auto
transportation, down to the basic motor vehicleerrand: One
passenger plus a sizeable payload, to and from destinations of up
to 5-10 miles away, rapidly, all at an affordable price.
And electric mobility scooters, unlike most electric
automobiles, seemed to already be on the right track -they just
needed to run faster. And, after checking the mobilityscooters on
the market, the HCF-305 seemed uniquely suited for the project. It
actually ran so fast that it got the manufacturer in trouble and
the medical mobility vendorsquickly unloaded their HCF-305
inventories. And I knew that this vehicle would be perfect for the
task.
I began to modify the HCF-305, by first installing an ultralight
aircraft seat and harness for comfort, stability, and protection,
and then building up the body around it.
This homemade vehicle is classified as a "Light Electric
Vehicle": A new breed of efficient, lean-and-mean machines that
weigh little more than the passenger(s). TheLight Electric Vehicle
is powered transportation distilled to its essence.
The issue with most electric vehicles these days is that they
often weigh in at 2,500 pounds or more. And such a vehicle has the
daunting obstacle of simply transportingitself, which is, at best,
a losing battle.
Another uncomfortable truth is that full size electric vehicles
put a strain on the local electric power grid: Most communities do
not have the electric power infrastructure,specifically,
neighborhood power lines and transformers, to properly charge more
than one or two full size electric vehicles per neighborhood.
Now, I have 3,000 miles (360 charge cycles) logged on this
vehicle. Everywhere I drive this odd duck people approach me,
wanting to buy one. I politely tell them that Iwould starve if I
made these things for a living.
This project is not unlike my radio control model aircraft: It's
a true labor of love -that requires a considerable amount of
research and tinkering to keep everything runningsmoothly. But the
casual bystander only sees a cute, reliable vehicle that quickly
and effortlessly runs errands all over town. And it would be a
quite a stretch to assumethat this vehicle is anywhere near ready
for the mass market.
Like many members in my local Electric Automobile Association, I
see my electric vehicle as a toy and a joy, and certainly not yet a
viable substitute for an internalcombustion engine vehicle.
But we try.
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Step 1: Unorthodox Treatment for High Rate Sealed Lead Acid
Batteries:After quickly burning out two OEM 24 Volt 40 Amp battery
packs, after only 50 miles each, I've installed and had excellent
results with a different replacement set ofbatteries for my light
electric vehicle:
Four - 12Volt, 21Amp PowerSonic PSH-12180NB-FR batteries,
producing a 24 Volt, 42 Amp battery pack.
But, upon receiving the delivery of the batteries, I promptly
pried off the sealed plastic panel, which covers the six soft
rubber valve caps to the cells, and added almost 1-1/2 fluid ounces
(44.4 milliliters) of standard battery electrolyte solution (an
over-the-counter product of 35% sulfuric acid and 65% water) to
each cell, for a total of 9 fluidounces (266 milliliters) per
battery. The electrolyte level just needs to cover the lead plates,
and no more. Standard lead acid batteries require topping off with
anelectrolyte level of almost 1/2" over the lead plates, but your
sla agm batteries are far better off with less.
To inject the electrolyte into the cells, I prefer to use a
small, el-cheapo battery electrolyte bulb tester, with the colored
plastic balls removed. The pointed tip of the bulbtester is
inserted into the small cell opening, and the electrolyte is
quickly squirted into the cell so that the solution doesn't have a
chance to flood onto the outside-top ofthe battery. The battery
cell is then inspected with a small led flashlight, to see if the
lead plates are just covered by the electrolyte, but no more. A
darkened room, orshed, is best for this. A thin, plastic drinking
straw (chemically inert) comes in handy, in case a bubble in the
cell hole is blocking your view, to poke it and pop the
bubble.Breaking open and "topping off" a perfectly good set of new
batteries and voiding the warranty may sound shocking and radical
to most people. But, after thoroughly
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reading up on the subject, I came to the conclusion that my
judgement is correct -and the advice of the battery specialists is
either wrong or non-existent. You see, sealedacid batteries are, by
their very nature, "starved electrolyte", due to the simple fact
that the fiberglass mats between the lead plates are only 95%
saturated, in order tomake them spill proof. As such, water
depletion of the "sealed" system is a constant concern. Performance
can only take a back seat when a battery is designed this way.
Another benefit of flooding a sealed lead acid battery is to
provide an inherent ability to dissipate heat. That is, typical
flooded deep cycle batteries may normally becomewarm to the touch,
either from heavy use, or from quick charging, but if a sealed lead
acid battery ever becomes hot (or even warm) to the touch, the
internal lead/glassmat cells, more than likely, have dried up and
burned out, due to the complete inability of the empty spaces in
the cells to dissipate intense heat away from the leadplates.
Another symptom of a sealed lead acid battery that is burned out
(aka: thermal runaway) is that it also vents off a sick vinegar
smell.And if the new high-rate sealed lead acid batteries were
truly reliable, then why haven't the golf cart manufacturers
installed them, making their vehicles lighter and moreresponsive? I
feel that those relatively expensive, compact, and high-performance
sealed lead acid batteries must be flooded (electrolyte added), to
enjoy their maximumpotential.
The electrolyte added, the six soft rubber cell caps were
replaced onto the battery cells, and any spilled electrolyte from
the top of the battery cleaned up with a papertowel. I then
punctured each of the six soft rubber cell caps, in the middle,
with a standard push pin, to eliminate the internal vacuum that
happens as the batteries coolback down to ambient temperature,
causing the electrolyte in the glass mats to deplete to less than
95% saturation (*** Warning: At one time, with an earlier
batterypack, I placed the battery cell caps on a wooden board and
punctured each one, in the middle, with a heated, red-hot
straightened end of a paper clip, for even betterventilation of the
cells, but the possibility of an electrical spark causing a battery
explosion is greatly increased by the larger diameter vent holes
and I no longer do it thisway). The now-flooded batteries, simply,
do not have to be completely "sealed". The plastic cover was then
fitted back into place, over the cell caps, and taped
shut,lengthwise, leaving the ends uncovered, to allow for venting
of the battery.
Working with battery electrolyte solution does require certain
precautions (some say it's dangerous -but so is using a table saw,
or driving a car):- Only use standard battery electrolyte solution
(an over-the-counter product of 35% sulfuric acid and 65% water).
Never use pure sulfuric acid. It is extremely dangerous,as well as
ineffective. And "topping off" with water will only weaken your
sla/agm batteries, as they are not at all like typical flooded
batteries.- Make sure that there is someone nearby, within shouting
distance, just in case electrolyte gets in the eyes, to help flush
your eyes with water, or better yet, specialemergency eye-flush
solution. Or, if heavy electrolyte contact, a trip to the emergency
room of a local hospital (but still do a first aid flush, as time
is critical).- Wear eye protection and wear old, worn out clothes.
Small droplets of electrolyte have the insidious habit of producing
large holes in your favorite yard work clothes,appearing a week or
two after exposure. Cellulose products are surprisingly vulnerable
to electrolyte solution (blue jeans, canvas shirt, wooden floors).-
Snug fitting latex (or nitrile) gloves should be worn. I only wear
them sometimes. But any case, afterwards, hands should be scrubbed
down with baking soda, and face,hands, and arms washed with soap
and water.
The four - 12Volt, 21Amp PowerSonic PSH-12180NB-FR batteries
were then wired, in pairs, in series, and then parallel wired, to
produce a 24 Volt, 42 Amp battery pack.
But further reading on the subject indicates that the batteries
may function better if first wired parallel, as 2 - 12 Volt groups,
and then wired in series, to produce a 24 Voltbattery pack. The
reason for this is that a weak battery will not degrade the
over-all battery pack as much, in this type of arrangement.
A 7/8" thick pad of Insulite, a closed-cell foam, resistant to
battery electrolyte solution, was positioned under the battery pack
to absorb road shock, as the shockabsorbers on the vehicle were
adjusted to maximum stiffness, to create a more efficient ride and
maximize the range of the vehicle.These high rate PowerSonic
batteries were actually developed for emergency power backup
systems, for computer networks, etc.. Although tried and proven in
electricwheel chairs that cruise at 3-4mph, these batteries have
not been extensively tested on higher performance powered vehicles.
But they are formulated for high-drainusage -without damage. Also,
being agm (absorbed glass mat) batteries, they have a strong
tolerance of the shock and vibrations of an electric vehicle
environment.The caution here is that the HCF-305 is unique in that
the OEM electronic controller allows the 600 watt motor to run the
vehicle at 14 mph. This is a world of difference,from running, say,
a 600 watt motor in a vehicle that will max out at 4 mph. In short,
a set of sla batteries that have successfully run a wheel chair for
years can quicklyburn out when connected to a high performance
electronic controller (as in the HCF-305) that runs a vehicle at 14
mph.The original OEM battery pack (2 - 24V 20A batteries) for the
HCF-305, at 24 Volts / 40 Ampere-hours capacity, is just not
durable enough to power the vehicle at a14mph cruising speed. It
should have been designed with a 24 Volts / 70 Ampere-hours
capacity sealed lead acid/absorbed glass mat battery pack + a 24
Volt / 70 Ampelectronic controller, for this type of load. The OEM
battery pack was designed to cruise at about 8mph, with , maybe,
occasional 14mph speeds for racing against othermobility scooters
out of the stoplight.
But this limitation can be worked around. Read on.
And another warning: Don't be tempted to build a custom 24 Volt
battery pack that exceeds 40-42 amps. Doing so will quickly burn
out the electronic controller. Andsubstituting a higher capacity
electronic controller will create a loss of many of the special
functions that are unique to the HCF-305's performance and
convenience. Inshort, a high performance, off-brand electronic
controller will simply run the motor -and nothing else.
Measuring the same height, the same length, and half the width
of the standard issue HCF-305 batteries, the pack of four
PowerSonic replacement batteries fit snuglyinto the HCF-305 battery
compartment. Be sure to fashion a means to tightly secure each and
every battery into position. The HCF-305 has minimal sized
shockabsorbers and any bumping and movement of the batteries WILL
cause the battery cables to come untightened and loose. And the
amperage running in the batterycables is strong enough to melt
steel.
Although the new batteries arrived pre-charged, it is imperative
that the modified "topped off" set of batteries were given a full,
overnight charge, using the standard HCF-305 charger. After
charging, each battery will test at 13.5-14 Volts -yet another
advantage of adding standard electrolyte to the sla batteries,
adding extra "pep" to theperformance, without overloading the
HCF-305 electronic controller.
It makes no sense to enhance the battery pack performance on the
HCF-305, if full power is restricted from reaching the electronic
controller, and the motor. Specifically,the OEM 12AWG wiring
harness needs to be replaced with a custom, more robust 10AWG
automotive wiring harness.
The problem with the OEM 12AWG wiring is that it is really not
adequate for fast discharge characteristics of running the HCF-305
at full cruising speed. The OEM 600watt motor is also wired with
the same 12AWG wiring, indicating that the motor manufacturer
probably never intended that their motor be run that hard.
Also, the cross-section of the OEM 12AWG wire has no less than
65 fine copper wires, that are extremely vulnerable to trace
amounts of battery electrolyte wicking deepinto the wiring (acid
wicked in and damaged 10-1/2" / 27cm of wire on my HCF-305!).
Whereas standard 10AWG automotive wiring is much heavier, capable
of handling60% more current and, more importantly, the
cross-section a typical 10AWG automotive wire has about 19 coarse
copper wires that are far less likely to absorb batteryelectrolyte,
and if that happens, is somewhat less susceptable to acid corrosion
eating through the wiring, blocking the high flow of current.
Once fabricated, the lugged contacts, on the new red and black
10AWG battery pack cables, need to be carefully "tinned" with an
electrical rosin core solder, to make thebattery wiring more
efficient. The battery pack cables have battery contacts that are
originally crimped on, which can sometimes restrict large amounts
of current to freelypass through, causing a "hot spot". Lead-based
solder, with a much lower melting point (374 degrees Fahrenheit)
than lead-free solder (430 degrees Fahrenheit) willfreely melt into
the copper braids of the wiring, with a 75 watt soldering gun, for
a clean, heavy flow of DC current. Lead-free solder will probably
require a butane penciltorch, to overcome the heat-sink nature of
the heavy copper wire and quickly melt the solder well into the
connector and wire.
But, if you choose to add electrolyte to your sla batteries (and
you should), "tinning" is a required step. The reason is that there
will always be trace amounts of electrolytethat somehow make it
outside of the battery (from riding the vehicle over rough
surfaces, etc.), and make contact with the battery terminals and
battery connections. And
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once on the connections, an even miniscule amount of electrolyte
can quickly wick into the braided copper wiring, to do its mischief
and impede in the proper flow of DCcurrent. "Tinning", while not
preventing this corrosion, will effectively ensure a clean, heavy
flow of DC current through the wiring at all times.
Initially, I simply cut off the OEM wiring connectors and
replaced them with heavy duty 12-10 AWG ring terminals, for a
#8-#10 stud, crimped onto the battery pack cablesand "tinned" with
liberal amount of solder. And then applied and worked in liberal
amounts of special battery terminal grease, which also has special
inhibitors toneutralize battery electrolyte.
The battery terminals and wiring connectors must be clean at all
times. The powdery deposits that sometimes form on the terminals
are result of battery acid corrosion.The battery pack can usually
be charged through corroded contacts. But the high rate of battery
discharge, required for driving the vehicle, will create "hot
spots" wherecorrosion is present, greatly diminishing performance
of the vehicle.
To remove corrosion from the battery terminals, I've found that
a good spray of "Windex" window cleaner (substitute brands don't
work as well), with its alkalinecomposition, quickly dissolves most
corrosion and also wicks into the wiring harness to further
dissolve any hidden corrosion. Saturating an old toothbrush with
Windexworks well in removing acid corrosion from the more stubborn
areas.
"CRC" brand Battery Cleaner with Acid Indicator is also a quick
and excellent aerosol product that has a thorough foaming action,
with a yellow colored foam that turnspink, upon contact with acid.
A second application, in the pink areas, leaves a thoroughly clean
set of battery terminals and connectors. The instructions on the
canrecommend flushing with water, but I simply wipe clean with a
paper towel, leaving some foam residue to neutralize any acid that
might reappear.
If this doesn't completely remove all corrosion, take a small
brass bristle brush (the size of a tooth brush) and carefully
remove the remainder of the corrosion from thebattery terminals and
connectors. Any stubborn areas can be removed with a small, sharp
knife. Medium-coarse steel (soap-free) can also be used ensure a
solidelectrical connection. Wipe dry and allow everything to air
dry completely. To prevent corrosive deposits from forming again,
coat the terminals and wiring connectors witha liberal application
of dielectric grease -or even better: A silicone dielectric
terminal grease.
The new battery pack also needs to be gradually "broken in".
That is, run your HCF-305 no more that 2 miles on the first test
run. Then completely recharge the batterypack. Run your HCF-305 no
more than 4 miles on the second run, and recharge. 7 miles on the
third run, 9 miles on the fourth run, 11 miles on the fifth run,
and 14 mileson the sixth run. Your battery pack is now ready for
hard use.
The HCF-305 should now have a maximum range of 15.5 miles on a
smooth surface in open country, or 9.5 miles in neighborhood
stop-and-go traffic, at 15 miles perhour.
The first test run on the HCF-305, the vehicle was driven at
full speed, for about 8-1/2 miles (but don't do what I did -see
above), before the heat sensor in the motorcaused the circuit
breaker button to fully extend out, turning off the power to the
vehicle. Following the instructions of the HCF-305 Operator's
Manual, the vehicle(actually, the motor) was allowed to cool off
for about 20 minutes, before the circuit breaker button was pushed
back into the flush (reset) position, and the HCF-305 wasturned on
and driven home, about a mile away, with power to spare.
Before the second test run, a digital speedometer/odometer was
installed to provide greater accuracy. A digital odometer is
especially useful when operating a LightElectric Vehicle, as it
provides a clear, precise display of the remaining mileage on your
vehicle.
* Here are the results with the PowerSonic battery pack (on a
smooth, paved surface, and with the modified bicycle trailer in
tow):Maximum speed: 15mph (24.2kph)* Maximum Range (on a smooth
surface, in open country):15.5miles (24.9 kilometers) @ 15mph
(24.2kph)31 miles (49.9 kilometers) @ 9.2mph (14.8kph)46.5 miles
(74.8 kilometers) @ 4.6mph (7.4kph)
* Maximum Range (in neighborhood stop-and-go traffic):10 miles
(15.3 kilometers) @ 15mph (24.2kph)20.5 miles (30.6 kilometers) @
9.2mph (14.8kph)31 miles (45.9 kilometers) @ 4.6mph (7.4kph)* It's
important to note here that the above are MAXIMUM ranges. That is,
I ran my electric vehicle, at full cruising speed, until the
electronic controller shut it down, andthen carefully noted the
miles. This is not recommended, if you want your battery pack to
enjoy a satisfactory lifespan. Doing so (driving your vehicle hard,
until it justcrawls back home) is commonly known as "batterycide".*
Running the above mileages, per charge, your battery pack will last
about 1,000 miles / 120 charge cycles. But simply running your
vehicle at 2/3 the above mileages,maximum (but still cruising at
15mph), will double the lifespan of the battery pack, to 2,000
miles / 240 charge cycles, which I've found to be a better
trade-off.* It's also important to note that the average annual
temperature of where I live and drive my electric vehicle is 58.6
degrees Fahrenheit (= 14.8 degrees Centigrade). Ifyour average
annual temperature is higher, then expect your battery pack to have
a somewhat shorter lifespan. If your average annual temperature is
lower, then expectyour battery pack to have a somewhat longer
lifespan.
The above mileage is at an ambient operating temperature of 70
degrees Fahrenheit. Driving in cold weather can reduce range, and
driving in warm weather canincrease range as follows:
100 degrees Fahrenheit: 128% range With dual LED headlights on:
115% range
90 degrees Fahrenheit: 119% range With dual LED headlights on:
107% range
80 degrees Fahrenheit: 109% range With dual LED headlights on:
98% range
70 degrees Fahrenheit: 100% range With dual LED headlights on:
90% range
60 degrees Fahrenheit: 87% range With dual LED headlights on:
78% range
50 degrees Fahrenheit: 74% range With dual LED headlights on:
67% range
40 degrees Fahrenheit: 61% range With dual LED headlights on:
55% range
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30 degrees Fahrenheit: 47% range With dual LED headlights on:
42% range
* Increase above ranges 75% if PowerCheq electronic balancing
modules are installed in the battery pack (see PowerCheq page in
this Instructable).One possible complication, though, is the
HCF-305 motor overload sensor. While this valuable feature will
prevent the motor from overheating and burning out,
thesensor-activated circuit breaker, after about 4-1/4 miles of
hard riding (at 15 mph) will kick in at the darndest times, such as
when speeding through a busy intersection,etc.. At full speed (15
mph), the heat sensor, inside the aluminum end plate of the motor,
signals the electronic controller, which makes the decision to shut
down thepower, at 126 degrees Fahrenheit, causing the HCF-305 to
come to a complete stop. A short wait, of a few minutes, is all it
takes for the motor to cool off, and thevehicle's circuit breaker
can be reset.
Or, a better option: Accelerate to full cruising speed, then
back off on the throttle until there is a noticeable drop in speed,
then increase the throttle ever so slightly back tofull cruising
speed. You'll cruise like a pro. And, more importantly, you'll be
able to cruise at a sustained cruising speed of about 15 mph, and
the electronic controller willnow allow the motor to operate at up
to temperatures of 145-150 degrees Fahrenheit, without overheating
the motor.
The replacement PowerSonic battery pack requires a full 8 hours
to charge, before the amber charging led turns green. But a full
overnight charge (12-14 hours) is highlyrecommended. After a full
charge, each 12 Volt battery will test at 13.5-14 Volts.
Note that sealed lead acid batteries have a slightly different
electrolyte, which influences the terminal voltage. If you have
installed a set of PowerSonic batteries -andchosen not to break
them open and add electrolyte, a full charge voltage should read
about 12.8 to 14 Volts.
ALWAYS recharge your lead acid battery pack after a good run
(4-1/2 to 7-1/2 miles, or more). Failure to do so can cause
deterioration of the lead plates.Also, like Ni-Cad batteries, I've
read that lead acid batteries can also develop a memory. This means
that after a short test run around the block, for example, the
batterypack should not be recharged before storing the vehicle
away. Recharging the battery pack, as such, may adversely affect
the next cycle, reducing the range. I don'treally worry myself with
this possibility, but posted it as a precaution.
So far, the results from the new battery pack have been
dramatic. Costing about $ 260.00 American dollars, which included
shipping (but the price is going up in 2009), Ifeel that these
batteries will provide a compact, yet powerful and reliable
high-rate discharge system to power the HCF-305's 600 watt
motor.
My HCF-305 is now being run on as many errands around town as
possible, to find out how tough these improvised batteries really
are. Occasional checks of the batteryelectrolyte levels required
only a light "topping-off" of one cell, of one battery only, with
electrolyte (with these batteries, don't ever use distilled water
for topping off). Thebatteries in the battery pack were also
occasionally rotated, from front to rear, to distribute wear (if
any) evenly on the batteries.I've been asked: How does one know
when the electric vehicle battery pack has reached the end of its
lifespan? The answer is that the performance of the vehiclesimply,
and quickly, degrades to half the range, after a year or two of
service. Lead acid battery packs, in electric vehicles, are usually
replaced when the capacity dropsto 80% (80% capacity = 1/2 the
range of a new battery pack) or less. To fully understand the
usefulness of an old battery that is now at 80% capacity: Mark out
the "21Amp Hour" rating on the outside of the battery and write in
"16 Amp Hour" and treat the battery accordingly. But my "discarded"
12VDC sealed lead acid batteries (butflooded) are more than
welcome, joining up with the old battery pack of my wind generator
-or sun tracking solar panel, where they will continue to enjoy
years ofsatisfactory service.
The purist may choose to charge their custom battery pack, using
four 12 Volt chargers, one for each battery, to ensure a "balanced
battery pack". But this isunnecessary with the HCF-305, since the
batteries were ordered from the supplier, specified as a matched
set. Also, the HCF-305 electronic controller never allows
thebattery pack to discharge below 40 percent, so a possible weak
battery in the pack becomes less of an issue. And periodic rotation
(done every time the batteryelectrolyte level is checked) of the
battery arrangement in the pack tends to balance out possible
system stress on any one battery. The four 12 Volt battery
packarrangement is also defined a "low voltage traction pack",
which is not as maintenance-critical as the newer, higher voltage,
multiple battery packs in the newer electriccars on the market. A
"balanced battery pack" is essential for a lithium-polymer powered
radio controlled model airplane, but not for a pack of four lead
acid batteries,carefully protected by the HCF-305 electronic
controller.
But I am building a lightweight 12 Volt fast charger, which will
be permanently mounted on the vehicle, to take advantage of the
locally proposed electric vehicleinfrastructure, to double the
operating range of the vehicle. And it will require four 12 Volt
chargers, in order to carefully control the fast-charge
process.
The new battery pack will soon be wired with a fuse, on each
battery, so that a short-circuited battery won't destroy the entire
pack. The OEM battery pack wiringharness, oddly, is not fused.
Also, the series-parallel arrangement pushes the limits of what an
amateur should really attempt on these sort of projects, so stay
posted forspecific wiring details, complete with photos.
Powering your HCF-305 / Light Electric Vehicle with other types
of batteries:
The HCF-305 comes equipped with small, compact sla-agm (sealed
lead acid - absorbed glass mat) deep cycle batteries. The problem
is that, while deep cycle, thestandard issue WP20-24E batteries are
not designed as "High-Rate" batteries, in that they are not
designed to survive the heavy discharge demands of a 600 watt
motor.
But with the new breed of high-rate sealed lead acid batteries,
there's really no better class of battery for the task. Sealed lead
acid batteries first appeared in the 1970's,and have slowly
improved and evolved into today's SLA's, which have twice the
capacity, for their size, than those of the 1970's and 80's.
SLA/AGM's are now a betterchoice than lithium-ion batteries. Even
if not used, an electric vehicle, equipped with sla-agm batteries,
will lose only about 8% of its battery charge, per month. And
eventhat tapers off to only about 20%-30%, total, over a 6 month
period. But breaking open and flooding the battery pack with
electrolyte will cause the batteries to behave liketypical flooded
lead acid batteries, and battery pack will self-discharge almost 1%
per day.
Traditional flooded lead acid - deep cycle golf cart batteries
are just too large and cumbersome.Traditional flooded lead acid
automotive batteries are not designed to survive the deep cycle
applications required by electric powered vehicles. Using
standardautomotive batteries, in the HCF-305, will do permanent
damage with each cycle, destroying them after about 25 run/charge
cycles.
Deep cycle "marine" lead acid batteries (both flooded and
absorbed gass mat) are not suitable for powering electric vehicles.
Marine batteries have an internal designthat is somewhere between
that of a deep cycle golf cart lead acid battery and a traditional
flooded lead acid automotive battery. The problem is that the
initialperformance will seem spectacularly successful -until the
battery pack finally dies after about 50 run/charge cycles. But,
one real advantage of using marine batteries, isthat the harbor
masters, in many marinas, will freely give you their surplus used
marine batteries. The batteries will work, but are just tired, and
not up to full capacity. Nota bad deal for someone on the
cheap.
Sealed lead acid - gel batteries are now making their way into
electric powered "fun" vehicles. Sealed lead acid absorbed glass
mat batteries are sometimes mislabeled"gelcells" -which they're
not, but creates to the confusion. But, like most compact sla-agm
batteries, compact gel batteries cannot survive the rigors of 500
watt and 1,000watt motors. And, more importantly, having an
electrolyte in a gel state, they cannot be tampered with and
effectively serviced by the handyman. Sla - gel batteries
are,essentially, disposable batteries.
And don't be tempted to install a pair (or a four-pack) of
readily available Fisher-Price Power Wheels 12 Volt, 9.5Ah
batteries (wired in series) -or a pair Peg Perego 12Volt, 12Ah
batteries. Although a reliable, long-running power source for
childrens' toy cars, these types were designed to handle only dual
20watt motors, geared down torun at 3 or 4 mph. Running these
through a 600watt HCF-305 motor will quickly destroy them.
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Nickel metal-hydride battery packs (made of multiple 1.2 Volt
cells) are still too problematic for mobility scooter applications.
So are nickel-cadmiums. And an electricvehicle, equipped with NiMH,
or Ni-Cad batteries, if not used, will lose almost 10% of its
battery charge, per day!
Lithium-ion batteries are sometimes used in cost-is-no object
projects, to appear high-tech and gain instant credibility. But in
fact, the only "advantage" is that it wouldcost about an extra $
1,000 American dollars to outfit your HCF-305 with a set of
lithium-ion batteries, and they would still be the same size, same
weight, and same 40Amp capacity. But one little-known
characteristic of Lithium-Ion batteries is that they just can't
tolerate a fast discharge rate -especially the demands generated by
anelectric vehicle.
Also, the OEM electronic controller on the HCF-305 would need to
be replaced with a custom unit, since the lithium-ion battery pack
voltage drops dramatically duringnormal discharge, and the OEM
electronic controller, sensing a low voltage, would shut down the
vehicle prematurely, with less range than the standard lead acid
batterypack would produce.
The same applies to the new lithium-polymer batteries -except
that they do handle fast discharge rates quite well.
Fuel cell batteries, while promising, are too fragile, too
expensive, and still under development for light electric vehicle
applications. And even, if and when, they aredeveloped and
marketed, there is, at present, no infrastructure for readily
fueling electric vehicles.
LiFePO4 (Lithium Iron Phosphate) battery technology just may
change forever the light electric vehicle industry. The technology
is here, but at a cost of about ten timesthe cost of an equivalent
set of SLA batteries.
The development of truly new batteries for electric powered
vehicles has been painfully slow and stubborn, with no real
break-throughs in sight. False hopes have beengenerated by the
fabulously successful lithium-polymer batteries, now used in many
high-performance radio-controlled model race cars and model
aircraft. But thetransition of lithium-polymer power into electric
powered vehicles has just not been cost-effective. And, quite
frankly, not even effective.So it appears that compact sealed lead
acid absorbed glass mat batteries, with after-market electrolyte
added, are the best bet for powering the HCF-305. With a 1:4weight
ratio (battery pack : total vehicle), this is what the good
electric car of the future should be.I've been tempted to re-fit my
HCF-305 with two, switchable, 42 Amp Lithium-Iron battery packs
(one main + one reserve), to double the range -without increasing
theweight, or overloading the electronic controller. But, quite
frankly, am not willing to spend my time, driving my vehicle more
than one hour, while doing local errands.
A more provocative -and fun, idea is investing the extra cash in
a 24 Volt, 450 Watt wind generator and 110W solar panel combo, a $
1,500.00 package that also includestower hardware and an electronic
charging panel. http://www.home.earthlink.net/~hcf-305userforum
Image Notes1. Photo of initial battery pack wiring: Two - 40 Amp
fuses have since been added,as well as two PowerCheq battery
equalizer units, as well as 24 Volt wiring for anoccasional
electronic desulfator hookup. Both the red (+) and black (-) cables
ofthe main battery pack harness has also been modified so that
cables to the batteryposts are the same length. Stay posted for a
new photo upload.
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http://www.instructables.com/id/Light-Electric-Vehicle-One-Passenger-14mph-21/
Step 2: PowerCheq Electronic Battery String Equalizers Increase
the Mileage of the Battery Pack By 75 Percent!PowerCheq is a
real-time, electronic battery balancing system that equalizes and
maintains batteries during charge, discharge, and while sitting
idle. By continuouslyequalizing individual batteries, within a
string, batteries are properly maintained and kept at the same
state of charge. Operation during charging ensures that all
batterieswill receive a full and equal charge, thus preventing
undercharging / overcharging.
An excellent demo as to how the device functions can be found
at:
http://henot.longrine.fr/EV/PowerCheq.swf
As mentioned earlier, the four - 12Volt, 21Amp PowerSonic
PSH-12180NB-FR batteries are wired, in pairs, in series, and then
parallel wired, to produce a 24 Volt, 42Amp battery pack.
But it is not well known that, in such a battery pack, the two
batteries, attached to the final positive wire to the electronic
controller, discharge much faster than the othertwo batteries,
attached to the final negative wire to the electronic
controller.
This creates a serious imbalance that not only leaves unused
power, in the two negative-end batteries, but also reduces the
lifespan of the over-all battery pack -evenwith periodic battery
rotation.
My initial plan was to wire in a cumbersome, heavy-duty electric
switch, with eight wires from the batteries entering one side, and
two wires exiting the other side, to theelectronic controller. The
switch would be used halfway through the vehicle run, for the
return trip home. The sequence of the battery pack would be
completelyrearranged (aka battery rotation) and, I figured, would
increase the range of the vehicle by 25 percent and extend the
overall life of the battery pack.Yet, at the same time, I heard
about the PowerCheq battery string equalizer, which seemed to be
far more user-friendly -and efficient. But the reviews on the
internetseemed less than enthusiastic. And the manufacturer
(PowerDesigners) had removed the device from their website
(www.powerdesignersusa.com).After reading about the low performance
gains PowerCheq users reported, I feel that the issue is that the
PowerCheq device, which was actually developed for
electricwheelchairs and mobility scooters, was, in fact, purchased
and installed in full size electric vehicles. And, as could be
expected, the performance gains were, at best,meager, due to sheer
size of the batteries. In short, a PowerCheq battery string
equalizer will improve the performance of a 75 Amp-Hour battery,
but common sensedictates that only so much power can be transferred
through the thin 16awg-18awg PowerCheq wiring.
But things change when the PowerCheq is used with 21
ampere-hours (AH) batteries: The revolutionary device functions at
its best!The PowerCheq module interconnects the two 12V batteries
connected in each 24VDC series string, in the battery pack,
creating a bi-directional energy transfer pathbetween the
batteries. The module intelligently equalizes batteries during
charge, discharge, and idle periods, keeping them properly
maintained at the same state ofcharge -critically important to
battery life and range of the vehicle battery pack.
Only two PowerCheq devices were needed, as the simple parallel
wiring of the battery pack naturally works to balance the two 24VDC
battery strings.
Voltage checks, as well as amp-load tests, have been performed:
After charging, halfway through errands, and after returning home,
and the battery pack is perfectlybalanced at all times, with the
LED indicator lights on the PowerCheq modules constantly blinking
on and off, busily at work.
Each module, operating at 85 percent efficiency, transfers up to
2 Amps, while consuming only about 5mA current from the batteries.
After charging, the 6 watt floatcharge of the vehicle charger is
raised to a 7 watt float charge, by the PowerCheq devices.
More information about the device can be found at:
www.evsource.com/tls_powercheq.php
www.broadenedhorizons.com/powercheq.htm#specifications
Here are the results (on a smooth, paved surface, and with the
modified bicycle trailer in tow) with the modified PowerSonic
battery pack (broken open and flooded withstandard battery
electrolyte solution) with two PowerCheq battery string equalizers
installed:Maximum speed: 15mph (22.5kph)* Maximum Range (on a
smooth surface, in open country):27 miles (43.5 kilometers) @ 15mph
(24.2kph)54 miles (87 kilometers) @ 9.2mph (14.8kph) *This mileage
has been calculated -not road tested.
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81 miles (130 kilometers) @ 4.6mph (7.4kph) *This mileage has
been calculated -not road tested.* Maximum Range (in neighborhood
stop-and-go traffic):19.2 miles (26.7 kilometers) @ 15mph
(24.2kph)35.8 miles (53.5 kilometers) @ 9.2mph (14.8kph) *This
mileage has been calculated -not road tested.54.2 miles (80.3
kilometers) @ 4.6mph (7.4kph) *This mileage has been calculated
-not road tested.The above mileages are for an ambient operating
temperature of 70 degrees Fahrenheit.
The above results are preliminary, as the actual mileages were
done under less than optimum operating temperatures (Fall season,
~53 degrees Fahrenheit) and thencalculated to the projected 70
degrees Fahrenheit (normal operating temperature), and will be
fine-tuned over the next few months.* It's important to note here
that the above are MAXIMUM ranges. That is, I ran my electric
vehicle, at full cruising speed, until the electronic controller
shut it down, andthen carefully noted the miles. This is not
recommended, if you want your battery pack to enjoy a satisfactory
lifespan. Doing so (driving your vehicle hard, until it justcrawls
back home) is commonly known as "batterycide".When the green led is
flashing on the PowerCheq unit it simply means that the device is
working hard at keeping the batteries in perfect balance, while
charging, or whilethe vehicle is running. Warning: The flashing
green led ceases to operate and the solid red led lights up when
the batteries discharge below a minimum voltage. At thatpoint, the
PowerCheq device ceases to balance the batteries and the vehicle
should be either recharged on the spot, or pushed home. Driving the
vehicle further willcause permanent, long-term damage to the
battery pack, shortening its lifespan.
Running the above mileages, per charge, your battery pack will
last about 1,000 miles / 120 charge cycles. But simply running your
vehicle at 2/3 the above mileages,maximum, will double the lifespan
of the battery pack, to 2,000 miles / 240 charge cycles, which I've
found to be a better trade-off.
That said, here are my most recent notes, to achieve maximum
range, as well as suitable performance:
Maximum Recommended Range At 15mph Cruising Speed:
100 degrees Fahrenheit: 17.0 miles .... With dual LED headlights
on: 15.3 miles
90 degrees Fahrenheit: 15.8 miles .... With dual LED headlights
on: 14.2 miles
80 degrees Fahrenheit: 14.5 miles .... With dual LED headlights
on: 13.0 miles
70 degrees Fahrenheit: 13.3 miles .... With dual LED headlights
on: 12.0 miles
60 degrees Fahrenheit: 11.6 miles .... With dual LED headlights
on: 10.4 miles
50 degrees Fahrenheit: 9.8 miles ..... With dual LED headlights
on: 8.9 miles
40 degrees Fahrenheit: 8.1 miles ..... With dual LED headlights
on: 7.3 miles
30 degrees Fahrenheit: 6.3 miles ..... With dual LED headlights
on: 5.6 miles
These revised mileages are not what I like, but are completely
satisfactory for local errands. Only time will tell if the lifespan
of the battery pack is truly doubled. There isanother advantage in
these reduced mileages in that the battery pack can truly be
charged overnight (9 hours), with the modest OEM battery charger,
and the vehicle willalways be ready to run again the next
morning.
When I purchased the PowerCheq devices, I figured that the
devices would increase the range of the vehicle by 25%. But the
tiny modules actually increased the rangeof the vehicle by 75% to
100%. And the humbling thing about it all is that I have no clear
idea as to why this happened, yet.
Anyway, the gold standard: A full run, on a smooth surface, in
open country (no stop-and-go) @ 70 degrees Fahrenheit, will be done
as soon as proper weather permits. But the final mileages are
actually expected to be slightly better.
I have to admit that I have been quite surprised with the above
results and waited over a month, after numerous test runs, before
reporting my results to the local ElectricAuto Association. And
it's also been fun running errands into the next town. It seems
that the age of the practical light electric vehicle is at
hand.
PowerCheq Electronic Battery String Equalizers (12V Module:
#401-PCHQ-12V-2A) can be purchased, for $ 58.99 each
at:www.evsource.com/tls_powercheq.php
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Step 3: 24V 40AH LifePO4 Battery Pack!Off-the-shelf technology
is changing so rapidly that as soon as I research, road test, and
fine-tune a high-performance deep cycle lead acid battery pack -it
becomesobsolete!
Specifically, the development of affordable ($ 450 + shipping),
drop-in-and-go Lithium Iron Phosphate (LiFePO4) battery packs,
complete with its own batterymanagement system and quick charger.
And this has all happened years before I thought it possible.
The reason why a LiFePO4 battery pack excites me is that it is a
true high rate battery (can take a heavy discharge load) and it has
a relatively flat discharge curve, sothat existing electronic
controllers, designed for deep cycle lead acid batteries, will work
quite well with the new LiFePO4 battery pack, without having to be
re-programmed.
The technology is improving so rapidly, that I am reluctant to
specify any brand names, as performance, quality, and prices are
expected to improve in the next few years(months?).But an excellent
first stop is www.ebay.com
Search for "24Volt LiFePO4 Battery" to bring up the latest
vendors.
I would buy and install a LiFePO4 battery pack right now, except
my deep cycle lead acid battery pack, with PowerCheq electronic
battery balancers, is expected to lastfor two years.
Note: The maximum discharge rate of these new LiFePO4 battery
packs range from 2C to 10C, depending on brand name. And I
recommend the high rate 10C units.
The C rating is the maximum safe continuous discharge rate of a
pack. If you see 10C on a battery pack, it means it can be
discharged at 10 times that packscapacity. Capacity refers to the
Amp-Hour rating of the battery, which will be listed as a number
followed by Ah (40Ah, for example).Theres the easy way to find your
batterys Maximum Discharge rate: Just multiply the number from the
C rating by the packs capacity.
Heres an example, using a 24 volt 40Ah - 10C battery pack:
40 Amps x 10 = 400 Amps Maximum Discharge Amperage
Divide by 2 = 200 Amps Rated (continuous) Discharging
AmperageThis means that you can safely draw up to 200 Amps
continuously from that 24 volt 40Ah - 10C without doing damage to
your battery pack, although I would still not
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want to put anywhere near that load on the battery pack.
A 24 volt, 40Ah LiFePO4 battery pack will also provide more
range than a 24 volt, 40Ah lead acid battery pack, because it can
discharge far more in a typical dischargecycle, to levels that
would damage a typical deep cycle lead acid battery pack. So expect
up to 50% more range.
LiFePO4 battery packs weigh only about half the weigh of
equivalent sealed lead acid battery packs, and are about half the
size of equivalent sealed lead acid batterypacks.
LiFePO4 battery packs are not as affected by low temperatures,
in contrast to a typical deep cycle lead acid battery pack, which
provides only half the range, at 30degrees Fahrenheit, than it
provides at 70 degrees Fahrenheit.
LiFePO4 battery packs have a useful life (down to 85% capacity =
69% range) of 1,000 charge cycles, in contrast to a deep cycle lead
acid battery pack (with electronicbattery management) that has a
useful life (down to 80% capacity = 50% range) of 250 charge
cycles.This technology naturally implies that larger, affordable
multi-passenger cars and utility trucks will be available to the
general consumer, soon.
Stay posted.
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http://www.instructables.com/id/Light-Electric-Vehicle-One-Passenger-14mph-21/
Step 4: Modifying the rake angle of the original HCF-305:The
rake angle of the original HCF-305's front wheels are
backwards!
Look carefully at any bicycle, or motorcycle, and you'll notice
that the front wheel slants well forward of the handlebars. A
typical motorcycle, for example, has a positiverake angle of about
30 degrees. The rake angle of a well designed bicycle, or
motorcycle, provides inherent stability, so that the rider can
easily ride without any hands onthe handlebars, yet continue in a
straight line.
But with the HCF-305, the problem can be corrected. The engineer
who designed the HCF-305 seems to have provided for a good,
positive rake angle, but, somehow,down the line, the front wheel
suspension was reversed (backwards). A quick examination underneath
will reveal that the front wheels need to be removed, leaving
thebrakes in place on the wheels. Both wheels are held on with
standard right-hand thread bolts, with 17mm heads. But be sure to
unscrew the tiny lock-screw, on thesteering arm, first. Then the
entire front swing arm / headset bearings / steering arm joint, on
each side, needs to be removed and switched left and right with
each other(leave the shock absorbers in place on the frame). The
steering arm, underneath the headset bearings, (also holds the
wheel axle bolt), will need to be installed upsidedown this
time.
But first, the original M10-1.5 pitch headset bolt needs to have
an additional 11mm of thread cut into it to properly fit into the
now upside down steering arm (a simplehandyman project). The brakes
(actually a drum, mounted permanently on the wheel hub, encircled
by a removable steel compression band), are designed to
primarilystop forward motion, so will have to remain on their
original sides and orientation. After the adjustments, the front
wheels will extend forward an inch or two, and thesteering tie rods
will now assume a more natural, horizontal position. My HCF-305 now
glides over bumps and rough roads much more smoother. Changing the
HCF-305's front wheel suspension to a proper rake angle will reduce
stress on the steering headset bearings, so that they will now
absorb bumps, at the angle they weredesigned to do, and pass the
shock of the bumps directly to the shock absorbers, which will also
now be in a better able to dissipate those impacts.
Modifying OEM 22" handlebar to a 29" Longhorn handlebar:The
HCF-305, being a "scooter", does NOT have pack and pinion steering.
This means, that at full cruising speed, the HCF-305 experiences a
slight loss of steeringcontrol, especially when riding over rough
paved surfaces. I initially planned to install a hydraulic steering
dampener in the undercarriage, but simplicity dictated thatadding
4" extensions to each end of the handlebars should provide the
proper leverage, a well as a natural steering dampener effect.
The steering system of the HCF-305 is well built, tight, and
secure. But the turning radius is just too tight for comfortably
running the vehicle at full cruising speed.I machined down two 7/8"
diameter hardwood dowels, 7-1/2" long: 4" @ 7/8" diameter + 3-1/2"
@ 3/4" diameter. The inside of the handlebars were degreased and
thewooden extensions were glued into place and then marine
varnished.
But the above steps are not a cure-all. My HCF-305 now leans
slightly out of the turn, and tends to slightly veer left and
right, from a straight line, while driving, but the theover-all
handling of the vehicle is definitely improved.
So feel free to alter the front-end suspension, but at your own
risk.
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http://www.instructables.com/id/Light-Electric-Vehicle-One-Passenger-14mph-21/
Comments9 comments Add Comment
lordgarion514 says: Dec 14, 2010. 2:04 AM REPLY12 volt lead acid
batteries don't top out at 12.6 volts, or even all that close
really. They actually top out at 13.8-14.2 volts(when newer of
course)This extravoltage used to be called "float voltage"(not sure
if they have a new name fir it now or not) But to get rid of
that'float charge" just run the lights for a few seconds-1 minute.
then you will be back to "normal full charge.Also heat affects
batteries very little nowadays, unless you have a battery installed
in a hot or cold climate and then move to the opposite climate.
Batterieslike gasoline are designed for the normal outside
temperature they are expected to run at.(example)batteries made for
use in very hot vlimstes have fewerplates that are thicker, this
allows the lead to withstand the extreme heat better but reduces
the cca's. Batteries made for extremely cold climates havethinner
but more plates increases the cca's but causing no problem with
lead deformation due to cooler temps. You wanna see a battery die
in a real hurry?Buy one from a desert location and then move to a
place like new york, or vice versa.
I found a good explanation of the effects of temps on battery
life on the net and will repost it here.
"Battery capacity (how many amp-hours it can hold) is reduced as
temperature goes down, and increased as temperature goes up....
Even though battery capacity at high temperatures is higher,
battery life is shortened. Battery capacity is reduced by 50% at
-22 degrees F - but battery LIFEincreases by about 60%. Battery
life is reduced at higher temperatures - for every 15 degrees F
over 77, battery life is cut in half"
Now this is usually not a real problem since the effects on
batters are not a one shot deal. In other words if your battery
spends 6 months a year at -22F yougain a 60% increase in battery
life.But if you spend the other 6 months of the year around 100
degrees you will lose about 60% of battery life, however it
willaverage out and the battery will last about the same as if it
was at 77 Degrees all year long.
lobo0x7 says: Jul 30, 2009. 6:16 PM REPLYwow shastalore! i am
amazed of your deeep knwoledge on batteries. good work, thanks for
sharing i am trying to put together some sort of e-vehicle and
youare the number one in my list of batterie gurus... can i make
you a couple of questions? one is: does it matters to mix diferents
sizes (amps) of batteries asfar as de volts are the same? and
diferents voltajes? the second one is a bit more general: wich
configurationn will you recomend for a ultralight e-motorcicle(or a
heavy bike) in order to have the better range possible (it will be
used mostly in town and in small road trips, so hi-speed is not a
must)? i meantbasically motor? watts? volts? (i still thinking in
mantain the pedals like in a bike specially for avoid the
motorcicle treatment by the road police), so, hubmotor? and wich
batteries do you recomend in order to have decent range without
beeing screwd by the prices of high.tec batteries? it was a lot
more than 2questions, after all thanks again
shastalore says: Jul 31, 2009. 11:31 AM REPLYThe batteries in
your electric vehicle should be a matched pack. That is, order the
batteries you need at the same time. All should be the same size
andcapacity. And, after receiving the shipment, be sure to fully
charge, and then test each individual battery with an amp / load
test. A simple $ 30.00 amp /load test meter can be purchased at
your local auto parts supplier. Check out my webspace link for the
details of using this device, as documentation andtechnical info is
notoriously absent with these inexpensive devices. And such an amp
/ load test will destroy a small SLA/AGM battery. A good rule
ofthumb is that 1 out of 10 (1 out of 12, in my experience) sealed
lead acid batteries, from the factory, will amp / load test as
"bad", or defective. I'm anadvocate of high-rate, sealed lead acid,
absorbed glass mat batteries, for light electric vehicles. They are
very tolerant of misuse and abuse. Other moreexotic batteries are
fraught with problems that the new experimenter is ill-prepared to
finance, problem-solve, and achieve satisfactory performance. Asyou
seem to just be starting into experimentation with light electric
vehicles (welcome aboard) I would suggest that you purchase a basic
electricconversion kit (rear wheel/brushless motor hub, battery
pack, controller, throttle grip), for an existing mountain bike.
Try for a 48VDC system, as it hasgreater torque, for hills and
such, than 24VDC (or 36VDC) systems. And a 500 watt motor would
provide enough power to go just about anywhere,although a 250 watt
motor would work just fine, if you live in a community with no
hills. I suggested a mountain bike, as I did just such a
conversion,about 15 years ago, by mounting a 2hp "chicken power"
2-cycle motor inside the bike frame, above the pedals. I replaced
the pedals with foot pegs,removed the chain and free wheel gears
(from the 26" rear wheel) and attached a half-gallon fuel tank
along the upper, horizontal frame tube. The frontfork had
motorcycle-like shock absorbers, and a large, round 12VDC malibu
halogen headlight completed the rig. The bike had a top speed of
24mph,and was street legal, in California, as long as the rider had
a valid California drivers license. And the bike was a totally cool
experience to ride: Isometimes passed oncoming Harley cyclists,
only to have them do a quick u-turn and catch up with me at the
next stoplight, thinking that I was riding avintage
turn-of-the-century "Merkel", or "Cyclone". But, to make a long
story short, it's essential that all electric vehicles be designed,
primarily, to beFUN. Otherwise, the performance will be just too
far behind that of gas powered vehicles, for most people to
tolerate their performance shortcomings.And 26" diameter wheels
(fitted with street tires @ 100psi) are, according to the simple
laws of physics, the most efficient size wheels to achievemaximum
speed, range, and comfort from your electric bike. Anyone, who
carefully thinks it through, will not purchase any of the foolishly
designed (yetexpensive) electric scooters with smaller diameter
wheels. An electric bike, with 26" diameter wheels, will achieve
about 50% more speed and range,than an electric scooter with 13.5"
wheels, even though both have the same battery packs. I really
don't know how the electric scooter manufacturersthink that they
can get away with this incredibly serious flaw. But, in China, the
typical electric scooter consumer is wise to this, and will only
purchase avehicle with a minimum of 24" diameter wheels (although
26" diameter wheels would be better). In fact, if I produce a
second version of my electric car, itwill have 24" diameter
die-cast aluminum wheels, while keeping the center of gravity the
same as the original version.
lobo0x7 says: Jul 31, 2009. 4:24 PM REPLYall right! thanks for
the advices and also for the nice story about your 2strokes bicycle
conversion. i did the same long time ago, but mine wasatachded to
the rear weel through a friction rubber caster! that allow to keep
the bicycle pedal wich, in spain, where a live, determines the
legaldiference inbetween a bicycle and a motorcycle, at least in
those times before the european regulations. my question about teh
size of the batteries isrelated with the position of the batts in
the frame. i was thinking in have a big 12v 45 amps from a car
right at the bottom of the frame to keep thegravity center al low
as possible and 3 more, small ones, designed for motorcycles, on
top, in order to reach the 48vots requiered. what do yo
think?thanks again, sash
shastalore says: Aug 1, 2009. 10:26 AM REPLYThe reason I
mentioned a mountain bike, with shock absorbers in the front fork,
is that in a motorcycle (or bicycle) 70% of the braking power is
inthe front wheel, and 30% of the braking power is in the rear
wheel, if one does a controlled stop. But, in sudden stops, that
ratio easily changes to100% of the braking power in the front
wheel, and almost no braking power is in the rear wheel, unless the
bike has shock absorbers in the frontfork (which will help keep,
somewhat, a 70/30 ratio). This is critical if you use street tires,
@ 100psi, for best rolling efficiency, but need to safelystop a
bike that has a heavy battery pack. Also, a mountain bike frame is
sturdy enough to mount a sizeable battery pack, and carry it
acrossvarying road conditions. And, as I mentioned, you should not
hesitate to romanticize when designing your electric vehicle. Every
effort should bemade to build it, primarily, to be FUN, and zany.
Otherwise, your electric vehicle will be perceived as lagging too
far behind, when compared to
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http://www.instructables.com/id/Light-Electric-Vehicle-One-Passenger-14mph-21/
gas powered vehicles, for most people to tolerate its
performance shortcomings -including you. In fact, I see this
strategy as the only thing thatwill prevent the demise of
contemporary electric vehicles. As for mixing different sized
batteries, to fit in your frame, it not only won't work, butwould
be dangerous. The reason I suggested a complete bike electric
conversion kit is that it usually comes with several battery pack
options topick from. And you can always design your own custom
battery pack, when you eventually know your rig inside and out, and
feel comfortable andproficient in designing your own battery pack.
12VDC SLA/AGM batteries come in all sizes and shapes, and it would
be possible to mix andmatch different shapes of identical Amp Hour
capacity, but you would no longer have a matched battery pack.
Also, electric bikes, motorcycles,and light electric vehicles all
require what is called a "traction battery pack". That is, a tough
battery pack that quickly discharge large amounts ofcurrent,
rapidly, without burning out. And the closest battery on the market
is the High-Rate 12VDC SLA/AGM battery, even though it was
notdesigned for an electric vehicle (it was designed for emergency
computer power systems). And, even then, I strongly advocate
breaking openthese new batteries and adding standard battery
electrolyte to the cells, which complicates things, as bicycles
tend to sometimes fall over on theirsides (and leak battery acid!).
But High-Rate 12VDC SLA/AGM's are the best available for the task,
and they are, at this point, relatively few sizesand shapes
available of this type.
lobo0x7 says: Aug 2, 2009. 6:28 AM REPLYhi, S! you are totally
right in your philosophie about to keep the vehicle as fun to ride
as possible. "it's essential that all electric vehicles bedesigned,
primarily, to be FUN. Otherwise, the performance will be just too
far behind that of gas powered vehicles, for most people totolerate
their performance shortcomings." yeap, and mine will be really fun
fun to ride and fun to wacht, i hope. i am thinking on it as a
weirdmixture out 2 bikes: a good one, the front one, carrying the
front suspension fork, the hydraulic brake disk, and a nice set of
everything , and asecond one, the scavenged one, wich will hold the
motorhub rear wheel, room for the electric setup, and all the space
that i think i will need,for stuff or for extra batteries due is
the only way that i can extend the range, right? the idea is to
make a tandem where the pasenger place istaken by an electric
fellas, and allowing the room for cargo or eventually for a human
passenger. it got to be strong as a rock but i can make itwith a
proper treatment of the lower conections inbetween the 2 bikes. i
shaw a couple of designs like this in instructables, an a lot of
similarconversions for 1 weeled cargo trailers, resulting in a 3
in-line vehicle. an easy adaptation to an electric pusher can by
taken from this point,but i want the real thing! a very long
bycicle, stable and fast as posible. light enough for still being
able to move it by pedals. but capable ofextend my range to at
least 100 kms, being lazy with the pedals, wich means colaborate
only when climbing and at the starts. i have beenmaking some
googling in sla batts and it seems to be ok for me except for one
thing: heat i read that heat will kill them pretty fast, and in
thecenter of spain we get 40C in the summer without any effort.
this vehicle should withstand stayin under the sun in such
conditions, wichmeans a few more degrees than that, due to the
facts than meteo readings are taken from a thermometer protected
with a shadow from dedirect sunlight. this is a lot of heatand i
think that this can be an issue. this is a lot of heat, wich batts
do you think can be the best for very hotclimas? one more question:
i am a bit afraid of the treatment that you recomend specially for
the leaking factor, smalls drops o streams of acidis the las thingh
that i want to see in my bike, but i am still thinking in give it a
try. the pictures of the batteries that i shaw did not show anyclue
on how to open them, they look like plastic bricks with 2 terminals
emerging. so i will prefer to try first the nice way and then, if i
feel like ineed more of the little boxes, broke open them and flood
the cells with electrolitic fluid, as you recomend. theres is any
problem with this? orthe treatment must to be done in a set of
fresh batts? thanks!! L
shastalore says: Aug 7, 2009. 10:20 AM REPLYI already have
another light electric vehicle in the works. I've accumulated a 750
watt electric motor, an electronic controller withmotorcycle
twist-throttle, and 3 used 12VDC batteries (from my existing light
electric vehicle), for a 36VDC system. The pedals werereplaced,
long ago, with foot pegs. Conservatively, I expect it to have a
range of about 24 miles (39 kilometers).When designing a light
electric vehicle, I urge one to plan a battery pack that will
transport the vehicle, passenger, and payload, at fullcruising
speed, for only one hour. Too many light electric vehicles are
designed with greater range (= longer cruising times), but then
alarger, heavier battery pack is needed, as well as a sturdier (and
heavier) vehicle, to carry the additional load. And this escalation
forgreater range and performance invariably creates an electric
vehicle that is so heavy that it has the daunting obstacle of
simplytransporting itself, much less a passenger and payload. Also,
are you really willing to drive more than an hour a day, doing
errands?
Everything (listed above) will mount on my old converted
mountain bike (with the 2hp chicken-power 2-cycle motor removed).
I'll also adda fake tear-drop "fuel tank" that will actually open
up as a glove box.
I'll also build a lightweight, removable side car, for hauling,
or to carry an occasional passenger.
But, an important note: The mountain bike wheels will have to be
replaced with a pair of diecast aluminum wheels. The side car will
alsorequire the same. The reason is that spoked bicycle wheels are
designed to handle tremendous stress, but only if they lean into
the turns(which is what ALWAYS happens on a bike). In short, if you
build a rig of more than two wheels, with standard spoked bicycle
wheels, allthe wheels will warp and destroy themselves, within in a
couple of weeks. They were just not designed to handle any side
stresses what-so-ever. There are some spoked wheels on the market
that are specially designed to handle the side stresses of a
3-wheel, and 4-wheellight electric vehicle, but proper spoke
adjustment/maintenance could be a problem.But the 3 wheeled rig you
described above, with all the wheels in-line, could be built with
standard spoked bicycle wheels, but the finishedrig might be
unwieldy, in actual practice.
Of course, I have yet to locate a set of 3 diecast aluminum (or
magnesium, or plastic) wheels, 26 inches diameter. And this project
hasbeen on the drawing board for almost two years. But don't rush
me, will ya.
As for your battery pack heating up in the hot climate, you
could always protect it with a reflective, insulated cover
(fashioned from achromed-plastic-bubble windshield shade). But I
just feel that the intense ambient heat, even in the tropics, would
only enhance theperformance of your electric vehicle. But you could
reference the technical notes of your battery(s) and simply find
out what temperaturerange they were designed to operate in.
KevinM says: Jun 14, 2009. 1:30 PM REPLYI'm flabbergasted at
your treatment of the batteries here. (wow!) Would you recommend
doing this to a standard car battery? I'm wondering about mine,
myvan has a tendency to kill the battery somehow, and after a while
it won't hold a charge from the alternator anymore. (I still have
to check the voltage accrossthe bettery with the vehicle running)
I'm thinking 'topping off the fluid' could be a solution to my
problem. I'm building a desulfator for this as well, as I think
itcould be a factor, but still.
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http://www.instructables.com/id/Light-Electric-Vehicle-One-Passenger-14mph-21/
shastalore says: Jun 14, 2009. 10:35 PM REPLYYour question is a
little out of the realm of this Instructable, but I'm answering it
because I have serious safety concerns: A standard automotive
floodedbattery is quite different from the high-rate sealed lead
acid, absorbed glass mat batteries, used in my vehicle. As for your
battery, the only fluid the end-user would ever add to the battery
would be an occasional topping off with distilled water. NEVER top
off with pure sulfuric acid. And don't top off withstandard battery
electrolyte solution (even though that's what is already in there).
Your alternator, if properly functioning, should register 13.5 VDC
to14.0 VDC across the battery terminals, while the motor is
running. If that's what you're getting, the the alternator is fine.
And when fully charged, and themotor off, a good automotive battery
should register at about 12.5VDC across the terminals. But that, in
itself, doesn't necessarily mean that the batteryhas the raw
cranking amps that you need. Is the battery old? Then it might
benefit from a 12VDC electronic desulfator. They can be purchased
for about$ 30.00, on ebay. They use very little battery power and
most can be left on the vehicle, even when it's running. Don't
waste your time with chemicaldesulfator additives on the market. Do
you use the vehicle for numerous stop-and-go errands? Or do you
have numerous, or high-drain 12VDCappliances on the vehicle? That
could explain the short battery life. Again, an electronic
desulfator may help. Also, there may be a short, somewhere onthe
vehicle, on wiring that is not fused. If so, turning on the key
switch (short of starting the motor) may cause the battery to
quietly boil inside, indicatingjust that. Also, check with a good
mechanic, about the brand names of good, reliable batteries on the
market. It your battery woes are from heavy useand demands on the
battery, they will be able to recommend special high capacity
brands, of the same size and dimensions. They'll also be quick
topoint out that that some of the cheaper brands are just false
economy. There are other unorthodox ways to rejuvenate automotive
batteries, but they'remessy, dangerous, environmentally unsound,
time-consuming, and I'm not going to go into them here. I hope this
helps. Good luck.