ELECTROLYTE LEVEL:
A low electrolyte level exposes active material, and any sulfate hardens and resists chemical action. Loss of electrolyte may be caused by a cracked case, poor maintenance (not adding water when needed), or severe overcharging which causes high internal heat and excessive gassing. Too much electrolyte is just as bad. Overfilling dilutes the electrolyte and spillage may corrode battery terminals.
OVERCHARGING:
Overcharging by the vehicle's charging system
or separate battery charger causes excessive gassing and
high internal heat. Too much gassing can wash
active materials off the plates, as well as cause
excessive water usage. Too much heat can oxidize the positive
plate material and warp the plates.
UNDERCHARGING:
A faulty charging system will not maintain the battery at full charge. Severe undercharging allows sulfate on the plates to become hard and impossible to remove by normal charging. The weak electrolyte freezes easier. The undercharged battery may fail to crank the engine.
CORROSION:
Spilled electrolyte
and condensation from gassing may cause corrosion
on terminals, connectors,
and metal holddowns/carriers. Such corrosion increases electrical resistance,
which reduces available voltage and charging effectiveness. It may also create a current leakage path to allow
self-discharge.
CYCLING:
Repeated cycling - from fully charged to fully discharged and back – may cause loss of active material from the positive plates. Thisreduces battery capacity and its useful life.
TEMPERATURE:
High temperatures from overcharging or engine heat can shorten battery life. Low temperatures can cause freezing of weak electrolyte. At 0°F (-17.8°C),
a fully charged battery provides less than half its normal power. At the same time, the cold engine requires twice
as much cranking power as it does with normal temperatures. The electrolyte in a fully charged battery will not
freeze until -60°F or lower, while the electrolyte in a fully
dis- charged battery will
freeze at +18°F.
VIBRATION:
A
battery must be mounted securely. Vibration can loosen
connections, crack the case, and damage internal
components.