What is -dV/dt charging ? (termination)
This is a charge termination method that detects a full battery when the Voltage of the battery drops within a certain time during the charge.
– means negative
d means delta/change
V means Voltage
t means time.
Delta can be translated as a Change. So if the charger senses a change in voltage so that the Voltage drops (which means negative) within X amount of time it knows the battery is fully charged. See this graph that HKJ made and look at the Red line. Just before it stops charging you can see it going down. The charger that uses a -dV/dt algorithm detects the battery is fully charged and terminates the charge.
The problem with low C charge rates is that the Voltage drop is difficult to measure. Therefore it is better to use a .5C or 1C rate when using this algorithm. Also notice that the black line, and temperature rises at the same time, they go hand in hand.
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