I received this charger free for review, but after using it I would spend $40 to buy another if needed. I found that once I bought a BLF Q8 that the 2-cell charger was no longer keeping up with my charging needs.
I have recharged a bunch of cells this week. It took all sizes that I own, and charged them quickly and safely. The Protected Keeppower 18650 – 3200mAh cell is long for some chargers, but fit fine. It states that it fits the 21700 cells, but I do not have any so I could not confirm this. It fits the fat 26650 cells in all four bays.
If I filled all 4 slots then plugged it in, I had to be quick to choose the rate of charge. I found I was not always fast enough and the fourth slot defaulted to the lowest setting. Double clicking the button put it back into select mode, then I could choose the rate.
The way I found I prefer to use this charger was to plug it in then add one cell at a time, starting with the outside slots. That way I could leisurely choose the fastest rate for each.
The picture shows 3 Samsung 30 Q button tops with the outside ones charging at 3 amps and another at 2 amps for a total of 8 amps. If you use all 4 slots then the most you can do is 2 amps each slot.
The two outside slots show 3000mAh which is three times faster than my Xtar VP2.
You can see that in this picture that I am charging two 26650 batteries at 2000mAh and two 18650 at 100 mAh. I could have done all 4 at 2000mAh.
What I like is that you can mix it up and do each slot a different cell type and a different rate.
Here I have one NiMH eneloop and a mix of protected and unprotected cells charging at different speeds.
What made me want this was the charging fast speed you are never going to get from a USB charger. I found that I just really like the simple controls: It always seems to know what type of cell I am using, but I can override it if I wanted to. There is one button over each slot and I can choose the speed I want, changing it mid-charge if needed.
In writing this review I read the others and I wanted to link to what I consider the definative review and the last word in testing. HKJ review of this charger:
http://budgetlightforum.com/node/56695
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