Transcript Maintenance of Batteries- Cost Effectiveness

Financial Impacts of
Battery Charging, Maintenance,
and Operational Problems
Potential Solutions & Benefits to Consider
Today’s Agenda
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What does a Battery Do?
Battery Operations and Expectations
Battery Ownership & Maintenance
Battery Ownership Costs
– Quantify the costs
– How to address these costs
– Benefits of implementation
What Does a Battery do?
• The battery provides two basic
functions:
– Power for the forklift
– Counterweight
How a Battery Works
• Fully charged
PbO2
– POS = PbO2
– NEG = Pb
– Electrolyte =
2H2SO4
Pb
H
2
S
O
4
• Two unlike metals
in sulfuric acid
++
Battery Design
• Forklift batteries are “Deep Cycle” batteries
– One discharge and one recharge is a “cycle”
– Our batteries are designed to exceed 1,800
cycles
– Today’s batteries’ lives are measured in
AH throughput, too
– When the battery fails to deliver 80% of its rated
capacity it is at the end of its life cycle (BCI
standard)
Battery Design
• A battery consists of:
– Two or more cells, connected in series
– Each cell is two (2) volts (nominally)
• 18 Cell Battery = 36 Volts
• A cell consists of:
– Alternating positive & negative plates
• Always 1 more negative than positive
– Plates are separated by microporous
separators for electrical insulation
Plate Design
• The structure of a plate
is the grid
• The grid is pasted, then
cured in ovens
• After curing, the plates
are “Formed” in our
exclusive open tank
formation process
– Fully formed plates
– Each one individually
inspected
The Deka Difference!
Battery Basics Summary
• Batteries consist of:
– Cells
• plates
– Steel tray
– Cables
• Life is measured in cycles & AH
throughput
• Proper use, charging, and care will
deliver long life and value to the customer
Battery Operating
Specifications
• The battery is to be discharged to 80%
depth of discharge daily
• The battery is to be fully recharged
daily (to nameplate SpG)
• The battery requires maintenance
– Equalize charging weekly
– Water when it is fully charged (~weekly)
– Washing about once a quarter
– Periodic testing and repairs
The Expectations of a
Properly Operated Battery
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Long life of the battery
High day-to-day capacity
High reliability
Minimal, if any downtime
Low operating temperatures
Lowest lifecycle cost to power the
forklift
The Deka Difference!
The Expectations of an
Improperly Operated Battery
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Shorter life of the battery
Reduced day to day capacity
Reduced reliability
Increased downtime
Higher operating temperatures
Higher lifecycle cost to power the
forklift
Operational & Maintenance
Areas of Concern
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Over-Discharging
Improper Charging
Lack of Equalize Charges
Watering
– Over or under watering
• Cleaning
• Physical Damage
– Cut cables
– Dented and/or damaged battery
Overdischarging
• Causes the battery to work “harder”
– Increases heat
– Stresses the cells
• Requires the battery charger to charge
at higher rates for a longer time
– Increases heat
– Increases gassing
– Accelerates “aging” and shortens life
– Can lead to thermal runaway where the
battery heat goes up and up and up...
Overdischarging
(Cont’d)
• Causes the forklift to operate at lower
voltages
– Shortens life of contacts/contactors
– Shortens life of motors
– Increases “down time” of forklift trucks
– Increases costs associated with operating
the forklift truck
Improper Charging
• Under or over-charging are detrimental
– Overcharging heats the batteries (>120°F)
– Undercharging creates:
• Lead sulfates
• Stratification (strong acid in the bottom)
• Heat shortens battery life
– For every 18°F >77 °F, life is halved
• Undercharging requires more frequent
changing and charging and reduces
overall life
Lack of Equalize Charges
• The required weekly Equalize charge is
simply a three (3) hour extension of the
normal recharge.
– Raises each cell SpG & Volts to their
maximum potential
– Reverses lead sulfates formed during
discharge
– If not provided, battery capacity will
diminish resulting in more frequent battery
changes and shorter life
Potential Causes of Over
or Undercharging
• Improper AH Matched Batteries & Chargers
– Charger too high, overcharges & overheats
– Charger too small, undercharges…
• Lack of Weekly Equalize Charging
– Can lead to sulfation not being removed,
reduced capacity, reduced life
• Both lead to shortened battery life,
capacity, and increase lifecycle costs
Under-Watering
Concerns
• If a portion of the plate “dry’s out”
– That portion cannot be resurrected
• Battery capacity is diminished
– The remaining SpG electrolyte increases
• Higher SpG accelerates grid corrosion
• Battery life is reduced significantly
• Battery failure is immanent
• Results in increased costs to operate
Over-Watering Concerns
• Electrolyte leaves the battery, spilling
into the truck compartment and onto
the floor. The result:
– Corrosion on the battery and/or cables
– Streaks on the battery sides
– Floor deterioration
– Reduced electrolyte SpG = less capacity
– “Overcharging” of the battery occurs…
• Heating results
• Reduced capacity, life, & performance result
Over-Watering Corrections
• What can we do?
• Send the battery to the shop for acid
adjustment and evaluation:
– Remove weaker and add stronger acid
– Battery capacity and recharge testing is
performed
– Train battery people to properly water
• Initiate watering equipment & PM of the
batteries & chargers
• Result: Battery capacity is returned
Cleaning
• When properly watered and maintained,
batteries should be slightly dusty on
their cell tops
– Ideally, the batteries should be clean & dry
• Quarterly washing seems to be
adequate and optimal
• Less frequent washing causes voltage
“tracking” on battery tops
– Can cause truck “faults”
– Corrosion is probable
Physical Damage Concerns
• Cut battery cables
– Potential for short circuit (safety)
– Battery is out of service
• Dented tray - damaged cell
– Battery is not functional
– Battery is out of service
Approximate Costs Incurred
• Sometimes the cost of repairs is material,
other times, costs are lost production.
• Production costs may be greatest...
• Improper charging, heat, & short life
$2,000
• Overdischarging and truck component
failures. Motors & contactors $1,000 to
$3,000
Approximate Costs Incurred
(Cont’d)
• Lack of equalize charging - short life
$1,000
• Acid adjustment & evaluation-$300 to
$500
• Cleanliness - causes warm batteries,
corrosion, rotted cables, holes in
operators’ clothing $100 to $500
• Damaged batteries $300 to $800
Recommendations
• Match the Battery AH to the Charger
• Replace if necessary
• Color code connectors
• Equalize Charge Weekly
• Set up chargers for auto equalize by:
• Day of week or Number of cycles
• Establish Maintenance Schedules
• Watering, washing, periodic testing
• Extend battery life
• Lower lifecycle costs, increase reliability, and value
The Deka Difference!
Summary
• Battery maintenance is known and affordable
• Battery maintenance can be done by your
adequately trained technicians, or, by the local
Deka Representative
• Costs associated with improper battery
operations and maintenance programs can be
substantial in terms of repair costs and lost
productivity. Corrective action saves money.
• Proper maintenance will yield lowest costs to
power the forklift trucks
Thank You!
For letting us present costs
associated with improper
operating and maintenance as
well as potential solutions.
How can we help you achieve,
The Deka Difference?