Best Practices for Warehouse Optimizationcdn.modexshow.com/seminars/assets-2012/219.pdf · Best practices to extend battery life • Equalization –Select ―weekend,‖ ―equalize‖
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Welcome to Session 219
Sponsored by: Presented by:
Joe LaFergola
Marketing Manger of
Information & Business
Solutions
Best Practices for Warehouse
Optimization
Best practices for
warehouse optimization
• Many factors for consideration:
– What are my maintenance costs?
– Do I have too many/few lift trucks?
• Are they being used properly?
– Am I maximizing my productivity?
– How am I managing other assets?
• How can I manage energy usage?
Best practices for
warehouse optimization
• One area that can have enormous benefits
to the bottom line:
– Lift truck battery
maintenance
Best practices for
warehouse optimization
• Agenda
– Battery 101
– Best practices to extend battery life
– Tools to make tracking easier
Battery 101
• Lead-acid batteries
– Rechargeable batteries
– Represent about 60 percent of all industrial
batteries sold worldwide
• Types
– Flooded (wet)
– Gel cell
– Absorbed glass matt (AGM)
Battery 101 • Advantages of each battery type
– Wet • Longer service life
• Easier to recharge when completely discharged
• Lower cost
– Gel cell • No liquid electrolyte to spill or leak
• Can be deep-cycled several times without damage
• Totally corrosion- and maintenance-free
– AGM • No liquid electrolyte to spill or leak
• Can be deep-cycled several times without damage
• Less expensive to ship (nonhazardous material)
Battery 101
• Electrical process
– All lead-acid batteries work on the same set of
reactions and use the same active materials.
Battery 101
Lead
Dioxide
(PbO2)
Lead
(Pb)
LOAD Anode - Cathode +
A chemical reaction within the battery causes electrons to
flow from the negative plate to the positive plate.
H2SO4
Electron flow
e-
e- e-
e-
Battery 101
• Battery life
– Average of five years
– Approximately 1,500 cycles
• A cycle is a discharge
(80 percent) and
charge (100 percent).
Battery 101
• Ampere-hour capacity – The electrical capability of a storage battery
• The number of ampere hours the battery can deliver under specified conditions
– Temperature
– Rate of discharge
– Final voltage
• Determined by multiplying the number of amperes the battery will deliver by the number of hours during which the current is flowing
Battery 101
• Rated capacity – The number of ampere hours the battery is
capable of delivering when fully charged and under specified conditions
–Temperature
–Rate of discharge
–Final voltage
–Specific gravity
– United States industry standards for motive power batteries always specify rated capacity to be at the six-hour rate of discharge.
Battery 101
• Voltage – Many voltage conditions have been
recognized for storage batteries.
– The most important of these are: • Open circuit voltage
• Initial voltage
• Average voltage
• Final voltage
Best practices to extend
battery life
• Charging – Under normal circumstances:
Charging is recommended
when a battery reaches 80
percent depth of discharge.
– Three ―8s‖ • 8-hour charge
• 8-hour cool
• 8-hour run
Best practices to extend
battery life
• Never overdischarge a battery – Will harm the battery and cause a lift truck’s
electrical components to run excessively hot
– Can easily increase the recharge time to recover, resulting in a battery that is only partially charged for the next day
– Can impact the ability to recharge because most automatic chargers must sense a minimum battery voltage to activate and turn on
Best practices to extend
battery life
• Temperature range
– Battery capacity is reduced
as temperature goes down
and increased as
temperature goes up.
Best practices to extend
battery life
• The standard rating for batteries is at room temperature (77°F). – At approximately -22°F,
battery ampere-hour capacity drops to 50 percent.
– At freezing, capacity is reduced by 20 percent.
– At 122°F, battery capacity would be about 12 percent higher.
Best practices to extend
battery life
• Equalization
– Select ―weekend,‖ ―equalize‖ or ―weekly‖ charge (depending on your brand of charger) approximately every five to 10 cycles to keep the battery performing at peak efficiency
– Failure to do so or selecting this option too often will harm the battery and shorten its effective life
Best practices to extend
battery life
• Watering
– New batteries require water approximately every five charges
– On both new and reconditioned batteries, check two or three pilot cells every two charges to see that the water level is just above the Element Protector
• If low, add only enough water to cover the Element Protector after charging to avoid ―boil over‖
What does this mean in ―$‖?
Scenario No. 1 — $$$
• 50-truck fleet
• $5,000 per battery
– Useful life = five years
– Typical life is four years or
20 percent reduction or
$1,000 per battery
• $50,000 in savings by extending
life to a full five years
Scenario No. 2 — Productivity
• 750 ampere-hour battery – 600 ampere-hour useful work
• 20 percent loss – 480 ampere-hour useful work
• 15 minutes to change battery – 4.2 percent productivity loss
– More batteries needed to accommodate a multiple-shift operation
– Added labor costs for more frequent battery exchanges and recharging
– More energy lost in more frequent recharging (the process is only about 80 percent efficient)