TM 116140203141
at the end of charge (approximately 130F).
1979 will not break down in the alkaline environment
(2) When the constant potential charging method
of the cell as did cellophane, and therefore thermal
is used, the current gradually increases rather than
runaway is much less likely with these materials. How-
gradually decreases.
ever, even with these new improved plastic materials,
(3) If the constant current charging method is
overheating and spewing of electrolyte can occur if ex-
cessively high potentials and temperatures are en-
used, runaway will be indicated by a decrease of bat-
countered.
tery voltage with time rather than an increase as is
usual.
d. Detecting Thermal Runaway. Thermal runaway
may occur if the batteries are charged for long periods
at high charging voltages or high temperatures.
The nickel-cadmium battery displays a much greater
Thermal runaway may be detected by the following
low temperature operation capability than the lead-
signs
acid battery. Usually, design specifications list the
(1) Battery temperature shows a significant rise
