Charging batteries

[Booldawg]

I can never remember the correct practise for charging a battery. Do you charge when completely flat or before it gets to that point?

[Khandro]

It is best that they are completely empty, my charger has a 'discharge' facility, allowing the removal of any 'juice' still in them.

[chas2008]

think its depends on the type of battery and usage,what Khandro says was the normal way but i have come across a couple of things recently where it states dont let the batteries go completely flat before charging.

[Hopkirk]

I think a car battery can be damaged by going completely flat.

[Graham-W]

Ni-Cad batteries need to be discharged before recharging as they develop a "memory" for the lower charge if charged early.
Lithium-ion batteries can be charged at will as they do not develop a "memory" like the Ni-Cads and generally hold a greater charge than the Ni-Cad equivalents.

[heathfield]

For some tips, scroll all the way down to 'Prolonging Battery Life'...

http://en.wikipedia.org/wiki/Battery_charger