Runtime test: Malkoff M61 and Keepower 16650 2000mah

I figured I'd post my results in case anyone else was interested. I'm running a Malkoff M61 in an otherwise stock Surefire C2 and powering it with some new Keepower 16650 2000mah cells I just got. This is the first use for this cell after charging it when I received it.

The light ran strong for about 2.5 hours before going dim and starting to taper. I'm not sure how long it would've continued to taper before (or if) protection had kicked in. At 2 hours 40 mins I decided to pull it and recharge the cell. It measured on my ZTS tester as having less than 10% of capacity remaining.

Just curious, the batteries are 18650 not 16650 right? I did some tests with an MD2, M61w, and 18650 3100 mah and was getting pretty decent output at the 2.5 hour mark and a volt reading of 3.42. At the 3 hour mark it was dimmer and reading 3.22, and at the 3.5 hour mark it was noticeably dim in output and read 2.77.

P_A_S_1 said:

Just curious, the batteries are 18650 not 16650 right? I did some tests with an MD2, M61w, and 18650 3100 mah and was getting pretty decent output at the 2.5 hour mark and a volt reading of 3.42. At the 3 hour mark it was dimmer and reading 3.22, and at the 3.5 hour mark it was noticeably dim in output and read 2.77.

Click to expand...

16650. Or maybe 16670, I can't remember. My C2 is stock, unbored, and I cannot fit 18650. I think 17s could fit, but I don't have any.

Are those cells charged to 4.20 or 4.35?

4.2 volts

Has the battery charged up fine after being drained thus.?
Or is it damaged?
I was looking at these and they have more capacity (manufacturer specs) than the 17650 version.

Looks like a good option for those who dont want to/cant bore out surefire lights and the like.

Charged up just fine. Much greater capacity than the two RCRs.

I've heard good things about these cells and the greater capacity compared to the 17670. I can get them in Europe and will have to get some. I have a M361 in a VME head and Vital Gear FB2 - this cell will be perfect. I thank you for your test and post. My wallet doesn't.