A customer charged some new Tenergy Premium D batteries on the xtar VP4 plus, fully charged up for the first time. Then, he took the batteries off and immediately back in the charger repeatedly, and they were showing around 80%, not full. So why did the charger not show full again for these NiMH batteries? More info here.
When the NiMH battery is nearly fully charged, estimating the charge in the charger to check its charging or not, is actually difficult, hard to gauge the SOC. For charging the NiMH battery, the full charge detection occurs by observing a slight voltage drop after a steady rise ( 0ΔV and -ΔV method). And the charger relies on the change of the voltage over time to determine when the battery is charged.
After a NiMH battery gets fully charged, take it out, and put it back into the charger again. The -ΔV is not so obvious, and the charger will make further charging. The charger may "re peak" the battery, automatically measure the battery voltage again, and may to charge it a bit more when it reaches its peak value.
To charge the NiMH battery in a smart charger, the data display on the charger is a reference value based on the voltage, not the actual battery capacity. Pls don't remove the battery until you see "FULL" on the screen. That means the battery got fully charged. To avoid over-charging, it's also suggested not to take the fully-charged Ni-MH battery out, and put it into the charger repeatedly.
When the NiMH battery is nearly fully charged, estimating the charge in the charger to check its charging or not, is actually difficult, hard to gauge the SOC. For charging the NiMH battery, the full charge detection occurs by observing a slight voltage drop after a steady rise ( 0ΔV and -ΔV method). And the charger relies on the change of the voltage over time to determine when the battery is charged.
After a NiMH battery gets fully charged, take it out, and put it back into the charger again. The -ΔV is not so obvious, and the charger will make further charging. The charger may "re peak" the battery, automatically measure the battery voltage again, and may to charge it a bit more when it reaches its peak value.
To charge the NiMH battery in a smart charger, the data display on the charger is a reference value based on the voltage, not the actual battery capacity. Pls don't remove the battery until you see "FULL" on the screen. That means the battery got fully charged. To avoid over-charging, it's also suggested not to take the fully-charged Ni-MH battery out, and put it into the charger repeatedly.
