The normal resting voltage for Eneloops is somewhere between 1.2V and 1.4V. During use, the average voltage is about 1.2 Volts.
So, why does my Eneloop charger stop charging at 1.6 Volts and sometimes at 1.45 V?
What is the maximum charging voltage for Eneloop?
That is normal behavior. It depends on the battery you charge, the charge speed, and how old/often it is used. But the ambient temperature also influences this a lot. If you charge a battery in a very cold room, your end Voltage will be higher than in a warm room. Also, keep in mind that the voltage will drop after it finished charging, so you usually don’t see the highest voltage unless you test it directly after the charge.
Please take a look at this graph below that is taken from a 4th generation Eneloop standard product sheet. You will see quite a difference in Voltage in relation to Ambient temperature.
The blue line almost reaches 1.7V when the ambient temperature is around 0 degrees Celsius. Many chargers have a cut-off voltage at around 1.65V.
When the temperature is 40 degrees Celsius, the end-voltage is much lower at around 1.55V.
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