What is an over-discharge?
This is a common problem when using batteries in a multi-battery application. Say for example a flashlight that uses 4 AA batteries in series. When 1 battery is charged for 50% and the other 3 to 100%, and you use the flashlight, the batteries will drain and the 50% charged battery will be empty before the others and the current keeps flowing through the battery which will damage this battery and increase its internal resistance.
It is therefore always advised to use sets of batteries always together, and the Eneloop limited editions will greatly help to keep track of your sets.
I asked some Eneloop engineers, who said that over-discharge is much worse than overcharge.
Over-discharge starts at 0.8V, and at around 0.6V damage will occur.
More questions about charging (Eneloop) batteries
+ Is slow charging better than fast charging for Eneloops?
+ What do mA and mAh stand for? And what’s the difference?
+ How many times can Eneloop rechargeable batteries be recharged?
+ Do Eneloop batteries need a special charger?
+ How long do Eneloop batteries hold a charge?
+ What is the recommended charge current for Eneloops?
+ What’s the best Eneloop charger?
+ Eneloop Voltage – what’s the deal
+ Can you overcharge Eneloop batteries?
+ What is the maximum charge voltage for Eneloops?
+ Do I need to charge my new Eneloop batteries before I start using them?
+ Should I discharge my Eneloops completely before charging them?
+ How long does it take for Eneloop to charge?
+ How do I need to Refresh my Eneloops?
+ Can I refresh Eneloops if I don’t have a charger with a refresh option?
+ How many years do Eneloops last?
Advanced Eneloop charging info
+ What is -dV/dt charging? (termination)
+ What is 0 dV/dt termination?
+ How are Eneloops tested to claim a 2100 cycle life? (IEC 61951/ JIS 8708)
+ Non-charge related questions can be found in the Eneloop FAQ