Good source/brand for the 26650 batteries?


Hi, I just bought the 2.6 kit ... and now I need to get 6X 26650 batteries.

Are there any recommended brands/sources? Doing a bit of digging online it seems like some passionate LED flashlight users recommend TrustFire 5000 mAh from DealExtreme ... has anyone had any experience with them? They are "protected" cells (protects against too-high-temperature and too-much-current draw, I think); is that OK/recommended?

Or any other suggested brand/sources?

Thanks! Looking forward to building this with my kids :)


Hi Michael:

If you look in the Dozuki instructions for 2.6, you'll see we recommend the TrustFire batteries.

We are considering changing our recommendation, since the Trustfire batteries do have a couple of issues related to ruggedness in extended field operations, and the over-current protection cuts out the cells just a little too easily. The batteries will work just fine at lower power settings, but at high power you will sometimes get nuisance trips of the protection circuitry.



Thank you Walt.

I bought the TrustFire 26650s, from Amazon, but I'm disappointed ... when I measure them with a simplistic battery tester at a slow (~220 ma) they are ~2500 mAH. The batteries claim 5000 mAH and others have tested them around 4000 mAH. I'm considering sending them back to Amazon ...

I may instead buy the IMR (high discharge current, no protection circuit, more "stable" chemistry maybe, popular with vapers mods!) 26650s instead, e.g.

But, it looks like the mAH of 18650 batteries (just thinner versions of the 26650) are not that much lower than 26650s, so I was wondering: is it possible to power the OpenROV with 18650s instead? The batteries would rattle around I suppose ... I could just stuff something in there to hold them tight. Has anyone tried that?


I just found these converter sleeves, to convert an 18650 into a 26650:

Seems promising...


Hi Michael:

Lithium Manganese batteries are indeed more stable that Lithium Cobalt, but I wouldn't recommend running them without a protection circuit. Here at OROV HQ we're in the process of switching over to Lithium Iron Phosphate (LiFePO4) batteries, which are the safest of all the Lithium chemistries. Look for an announcement on the blog in the next couple of days.

You can certainly use 18650 batteries in place of 26650, though be aware that it will change the buoyancy of the ROV quite a bit- you're going to have to add more ballast to make up for the lighter weight of the 18650 cells.



Thanks Walt.

I wound up returning the TrustFire 26650s to Amazon: they tested at only ~2500 maH, I'm not sure why (other's have tested them at ~4000 maH).

After reading some recommendations in flashlight and vaper's forums, I bought these LiMn 26650s instead:

I just tested one of them at ~3900 maH, much better!

However they don't have a protection circuit ... I'll try to be careful not to over-discharge or over-charge.


Also, you can buy the batteries with tabs, which I assume are then easily soldered together. I bought mine without tabs but now I'm wondering if I should have gotten the tabs for a better electrical connection...


Any ambition to claim myself as vaping/flashlight/battery expert, I’m real noob (especially in vaping), but MNKE batteries from seems to be a nice option for anyone looking for high-amps 26650s.