The higher the ambient temperature the better the reaction.
This is the reason battery sales spike in the winter months of the northern hemisphere when temperatures are lowerest.
1. Boil a cup of water. 2. Stand back and gently plunge 4 AA baterieries into the cup. 3. Let sit...untouched... for five minutes. NEVER MICROWAVE THE BATTERIES ! ! !
In most cases the batteries are good for 3 to 6 months more.
Sincerely, Gargoyle (I have used nearly a dozen hacks....but the hands down best....is to turn the #1 battery backwards until needed for use...the pack is always fresh.)