XTAR VC2 charger

I got an XTAR VC2 charger today. I took one of the 18650 batteries that my old charger indicated was charged, put it in the VC2 and the needle swung around to 4.2V. The capacity counter then started slowly counting up - what’s happening there? Surely it can’t determine the capacity without discharging the battery… there are no buttons to change from charge to discharge though. What’s going on?

It’s just displaying how much it has put in so far. Kinda like filling up your gas tank it doesn’t know how big your tank is only how much it has added it it.

Ah i see, so I’d have to completely flatten the battery before charging it to find out its true capacity.

Well, you got that kinda backwards. To get true capacity, you need to fill the battery, THEN discharge it while monitoring capacity. This is why analyzing chargers have an edge over chargers that claim to do capacity but don’t have dedicated discharge cap testing.

Filling a li-on from empty > full while monitoring isn’t ‘too’ bad. But it’s not optimal.
Filling a NiMh from empty > full while monitoring is pretty lousy and not accurate at all. You REALLY need to do discharge capacity on NiMh.

Ehh they’re panasonic cells from a trustworthy source and my PD35 runtime seems about right, I don’t think I care to find out the exact mah.

u need drain battery to around 3 V then u can get a estimated capacity when reached full.