Kyocera 7135 - Manual (Page 100)

82 Phone Care
Caution
Always turn the phone off before removing the battery.
Do not disassemble or short-circuit the battery.
Keep the metal contacts at the base of the battery clean.
If you have not used a battery for more than a month, recharge it before
using it.
Do not charge any battery if the temperature is below 32ºF (0ºC) or above
122ºF (50ºC).
Do not store any battery in hot areas for long periods of time.
Use these guidelines:
under 1 month: -4º to 140ºF (-20º to 60ºC)
over 1 month: -4ºF to 113ºF (-20º to 45ºC)
Never dispose of any battery in or near a fire. It could explode.