Protection Circuit (Against over charge, over discharge, over current and short-circuit.)
4.20V maximum voltage and 2.50V cut-off voltage
Over 500 charge-discharge cycles
This is a high current protected 18650 cell from Keeppower
Very good tracking in the discharge curves.
The cell gets rater hot at 15A
At 20A I stopped the test due to temperature.
This test only goes to 15A and did not trip the build in protection.
Protection will usual trip on 3 conditions: Over current, over charge and over discharge.
Conclusion
This is a good cell, but the build in protection do not trip on overload (It will probably trip on higher currents).
Results are pretty much identical to Enerpower’s VC+3000 cell (low voltage sag PCB).
Interestingly, there is one difference though. At 20A, the Keepower did not trip, and test was aborted due to heat. The Enerpower did trip before getting hot.
stephenk, or better don't buy lights which force you to use button tops, they're probably hiding some design deficiency (like lack of reverse polarity protection) or plainly wanting to rip you off. This is of course an opinion, not a rule.
Cheers :-)
P.S.: this KeepPower rewrap is likely Samsung 30Q based. The battery assembly slightly overheats at 15A continuous, this extra heat arises from the protection circuitry MOSFETs.
Hi! I was thinking of purchasing this particular Keeppower for both a ThruNite TN42 and also a BLF 8Q by ThorFire I am looking at purchasing. Would the Keeppower be a good match for these two flashlights or are there more compatible batteries? Thoughts? I currently have mostly ThurNite flashlights and ThurNite batteries that state they are 18650 “High Discharge performance Li-on” with “Integrated battery overcharge/discharge protection circuits.” This is why I was thinking of going with the Keeppower as it seems to sound the same as my current ThurNite batteries? Help is greatly appreciated as I am so confused by all of the different batteries and their compatibility….
Flat top, Button Top, Protected, Unprotected, 5A, 10A, 20A, 3.6V, 3.7V, etc… I am so worried I will not select the right battery and safety is very important to me.
I currently have these flashlights, but all with FACTORY batteries…
I do not know the different light and what batteries fit in them. Generally you have to look for;
Flat/button top: The positive connection in the flashlight, for a flattop battery it needs a dimple or spring to connect.
Protection: Do the light automatic turn off when batteries are flat, single cell LiIon light usually does and do not need protection. Light with batteries in series usually needs protection.
Length: Standard 18650 battery length is 65mm, but protected can be up to around 70mm. Light designed for protected batteries may not have long enough spring to handle 65mm batteries and light designed for unprotected batteries may not have enough space to handle 70+mm batteries.
In my experience, even cheap flashlights like the UltraFire SK98 or Convoy S2+ will do fine with flat top unprotected cells. This is because even if they lack low voltage warning or protection, their extremely simple drivers won't drain a cell below 2.5V even if left on unattended for days. I have not tried this, I tried an even more radical approach instead: I left a cell direct driven in parallel with a pair of wires attached to an led emitter until the emitter die was barely lit, it took a few days to reach that level. Despite this and the cell being an old chap, it still climbed back to 2.99V.
Boost drivers or multiple cell buck drivers are different beasts, these need and usually feature low voltage warnings and/or protection.