There was a point in my life where I was going to make my own solar batteries and I purchased around 300 21700 lithium sales to get started… Thankfully I got them from a bulk auctioner for almost nothing because I never ended up putting in the time to make more than one of the batteries as life just kept putting more important things in the way. At this point I have already said fuck it and simply purchased a large supply of premade solar batteries I did still get them from a bulk discount supplier to save some money.
The problem is that now I have a large supply of cells that I don’t know what to do with them they aren’t the standard 18650s so it’s not quite as easy to find things that will accept them. I have found a couple decent usb-c portable power bank cases that will accept these cells and I now have like five of those and it’s enough to charge pretty much any phone a good four times over which is nice but I need more uses I would like to put some flashlights in each of my vehicles to always have on hand and it would be neat if I could use these cells I’ve done a little bit of Googling but it seems like the options to accept this particular size is limited and I’m worried that they might be of poor quality.
Anyone got any recommendations on ones from a reputable supplier?
You must log in or register to comment.
There are many; the size has become very popular in the flashlight world. They range from $20ish budget options from Convoy to premium $100+ lights from Acebeam and Zebralight.
I maintain a recommendation guide that has some 21700 options, though that battery doesn’t get its own section. For an inexpensive general-purpose light to buy several of, I like the Convoy S21E configured as linked. The Nichia B35A LED provides outstanding color quality with good efficiency.
This light isn’t especially demanding electrically, so the concern another comment mentioned about pulling too many amps doesn’t apply here.
Wow thank you for the detailed reply the guide and the specific recommendation this should help me find exactly what I need to start making use of at least some of these cells
I hope it helps. Feel free to post about your short list to get additional insights. If you’re thinking about several lights for different purposes and you don’t have a lot of flashlight experience, it may help to start with one low-cost option and think about what you’d like to be different in subsequent purchases.
I do notice that a lot of these flashlights reference protected versus unprotected cells but I’m not 100% sure what they mean by that here is a picture of the cells I have I don’t know if those count as protected or not
Those are unprotected flat tops (bare cells).
Be aware that many high-power flashlights that take 21700 cells can pull a lot of amps, and since your cells are of questionable bulk origin, they might not be high-drain cells. It also varies whether flashlights take protected or unprotected cells.
For unprotected batteries, I like this site: https://18650-21700.com/
It’s been a while but I think it’s a two-person business. Unfortunately, my one experience buying from them was quite poor and I bought elsewhere. But the site has excellent info and seems to stay up to date on the best and latest batteries for high performance use cases.
One thing to note is that the site admin (Austin) focuses on rcs racing or something. It’s a different use case than flashlights and so I found that the judgements mixed into the information aren’t quite right. Still, the information is excellent and well presented. And it’s a simple place to find “the best” batteries currently available.
I have the molicel p50b’s. They’re excellent. Just be sure that you have a charger and flashlights that handle unprotected cells!
I have a wurkkos ts21 which is a fantastic all around flashlight that takes 21700 batteries and also works as a battery bank. There’s the sofirn lt1s lantern which also allowed reverse charging. Anything from sofirn, wurrkos, or lumuintop is going to be high quality.
There’s also some from Noctigon/Emisar.
Convoy S21e
