I recently purchased 4 Samsung batteries which were delivered in the guise of Panasonic(Sanyo) NCR18650GA high drain cellsin an EVVA wrapper. I've been assured the batteries I received are as good as or better than the ones I ordered. Okay, I'm new at this I can roll with it.
As part of my ongoing education and current obsession with all things related to LED flashlights and the batteries which power them I ran them through the mAh detecter mode of my relatively new Hohm Tech Base 4 Bay Digital Battery Charger. As I understand it, the charger charges the batteries (cells?) until the voltage stabilizes and then discharges them measuring the output in the process. Then it charges them back to full capacity.
These named/rated 3500 mAh cells completed the process indicating the following capacities:
1 @ 3322 mAH
1 @ 3328 mAh
1 @ 3039 mAh
1 @ 2381 mAh
I'm pretty sure the first two are considered within acceptable levels by battery people. The last two not so much.
This charger has something called a Battery Doctor Mode. It apparently oscillates and pulses with constant and stepping current to "revive, repair and nuture" weak or tired cells.
Well, after 10 hours or so, the cell previously measured at 3039 mAh finished up with 3322 mAh. After 13 hours the cell previously measured at 2381 mAh had increased capacity to 3328 mAh.
I don't know a lot about chargers but I believe Martha Stewart would call this one a "good thing".
I'm pleased.
I purchased the charger at the 18650batterystore
The owners manual (little sheet of paper actually) is here .