Vapcell S4 Plus V3.0 Cap Test shows two different Wh values?

[ronfc]

I’ve been using the charger for a month now and only today I noticed that the charger gives two different watt hour values during the cap test.

For context, I was cap testing a Fenix ARB-L21-5000 21700 5,000 mAh 18 Wh battery. 2A Charge current, 1A Discharge current. After the discharge phase, the charger measured 4,785 mAh 15.74 Wh, while after the end of the charging phase, it measured 17.22 Wh. The mAh remains unchanged. What does this mean?

[raccoon]

Thanks for joining the party, ronfc!

[texas_shooter]

It takes more energy to charge a battery than it holds. Some lost as heat in the cell as it charges. Some lost as the charging devices percentage of inefficiency.