It seems everything we use takes a battery, and battery life is not even close to that advertised. If you have battery troubles, here is the straight skinny, direct from the horse’s er, mouth:
DO charge your new battery overnight (14 to 16 hours) before you use it the first time.
DO store new or unused batteries in a cool and dry area. New batteries can be stored for up to two years without significant loss of charge/discharge cycles.
Do charge batteries that have been in storage: OVERNIGHT.
Do leave batteries in the charger an additional 1 to 2 hours after the GREEN light appears, when using Motorola chargers.
DO charge batteries only when they are fully discharged, to prolong battery life.
DO bring the batteries up to room temperature (72 degrees F) BEFORE charging.
DO NOT charge below 40 degrees or above 104 degrees F or battery life will be decreased.
DO NOT leave your radio or battery in the charger when charging is unnecessary. Continuous charging will shorten Ni-Cad battery life. So don’t use a charger as a radio stand.
DO NOT return fully charged batteries to the charger for an “extra boost.” You will significantly reduce battery life if you do.
That is from Motorola, obviously, and it applies to all Nickel Cadmium batteries.
Now, let me add something. If either a NiCad or a Nickel Metal Hydride, NiMh batter feels more than faintly warm to the touch take it out of the charger and discharge it completely. Flat! Then try charging it again.
Excessive warmth will raise the internal pressure in the battery, rupture the seals, and you may get another cycle or two out of it but it would be a good idea to start hunting new batteries.