Can you overcharge Eneloop batteries?
Yes, unfortunately, you can definitely overcharge Eneloop batteries. This is possible when you use a dumb charger (time-based charger). The charger will continue supplying a charging current for X number of hours. The battery charger will only stop when the timer has run out.
Another way is by trickle charging.
The most common problem is with using DECT phones that stand on a charging cradle most of the day. These charging devices provide a very low charge current to keep the batteries charged. The problem however is that Eneloop batteries don’t like this type of charging.
For Eneloop PRO batteries it is even disastrous because this will reduce their cycle life tremendously. This is because they are much more prone to heat and overcharging.
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