| Battery Applications & Technology
One of the most detrimental conditions for a
battery is high temperature, particularly above 55ºC,
because the rates of corrosion, solubility of metal
components, and self discharge increase with increasing
temperature. High operating temperature during cycle service
requires higher charge input to restore discharge capacity
and self discharge losses. More of the charge input is
consumed by the electrolysis reaction because of the
reduction in the gassing voltage at the higher temperature.
While 10% overcharge per cycle maintains the state of charge
at 25 to 35ºC, 35 to 40% overcharge may be required to
maintain state of charge at the higher (60 to 70ºC)
operating temperatures. On float service, float currents
increase at the higher temperatures, resulting in reduced
life. Eleven days float at 75ºC is equivalent in life to
365 days at 25ºC. Batteries intended for high-temperature
applications should use a lower initial specific gravity
electrolyte than those intended for use at normal
temperatures. Manufacturers should be consulted on
acceptable temperature ranges for operation of their
batteries and on the associated effects of temperature.
Nickel-cadmium batteries may be more suitable for
higher-temperature applications.
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