Imren 21700 4000mAh 35A Battery - Pack of 2

These batteries do great, I’ve been running them for over 24 hrs and they still have well over 50%. I’ll add that I am constantly ripping my vape. I’m not sure why people are leaving bad reviews because they purchased the wrong batteries. It clearly states the size in the description

I may be one of the only reviewers that actually like these batteries, or so it seems... I LOVE my old (Dovpo Topside 90w squonk) setup bc of the huge amt of juice it holds along w/ the fact that I can use either 18650's or 21700's - so I rarely have to worry about my power running out after a full day of heavy vaping. THESE BATTERIES give me that option, to go all day long - though I really wish they were 4500mAh (or evn 5000-5500mAh if they evn make them... if not, they should!) I will say that I agree w the last review about them being a little thicker** - though for me, that's a good thing bc they otherwise tend to rattle in my mod, BUT... as an **FYI sl(so ppl are aware), the HIGHER the mAh battery you go - the SIZE of the battery also slightly INCREASES ‐ which may be that reviewers issue, rather than the wrapper being the problem. I've tried several brands of batteries & always try to get the highest mAh they have in both 21700 & 18650's and that slight increase is always the case. As for these batteries, they're pretty spot on for power (as most usually test much lower than labelled), and the price is right for 2 w a case - originally about $19 & they seem to recharge in no time. Another hint for the last guy when charging - sometimes when they look like they're not connecting well, just give them a little 'spin' while sitting in the charger. For some reason it works like a charm ;)

I purchased these knowing they were 21700 size cells, but was surprised to encounter sizing issues as well. These batteries have extra thick wrapping causes the positive terminal to be submerged beneath the top of the battery, making them difficult to charge. The only charger they fit in for me was my 8 slot nitcore intelligcharger, and even then they have to be forced to fit. Inserting or removing them in a charger ends up damaging the wrap, and even rewrapping the batteries does not seem to fully resolve the issues. It's like they are a half a milimeter too big making them hard to use. Perform well otherwise, if you can fit them in chargers or devices.

I inadvertently ordered the wrong sized battery these are way too big.

Wrong size.