How many powerbanks do YOU have?

Because this is just what I could find of the “assembled and operational” variety. I’m fairly certain there are a few more out in my office, I just don’t know exactly where in my office…

Yes, I did play Ingress, why? And now, I’m pretty sure one or two of these would literally run my phone for the whole year. I should try it…

Slightly more on topic for power and reuse and such, these “assemble it yourself” packs (the nicer ones to work with are spring based and don’t require a spot welder) are a decent enough use for repurposed 18650s. It’s a 1S pack, so capacity balance between cells isn’t a problem, and as long as they’re all the same chemistry class (don’t go putting any LFP cells in with other stuff and a charger that terminates at 4.2V), it works out fine.

I could probably get rid of one or two of these if anyone local needs some capacity on the go.

None, but I’m becoming increasingly fond of using power tool (DeWalt in my case) batteries for this purpose.


  • Folks may already own a decent amount of capacity/chargers.
  • Often built with very high quality cells capable of very high charge/discharge rates with the adapter hardware.
  • The batteries are useful for their original purpose when one is not traveling or otherwise using them as powerbanks.
  • The fast charging makes tool batteries a pretty effective way to shift moderate amounts of load away from off-grid lead-acid batteries if one charges them during the day and after the lead-acid batteries’ charge rate has started decreasing.


  • Many of the adapters don’t come with a functional low voltage disconnect so be prepared to do a bit of surgery to add one - or use them very cautiously.
  • Could add wear to batteries that might have “higher value” use.
  • Expensive.

Outside contractor daily use, I’d expect tool batteries to calendar out before cycling out, so probably fine for personal use. What do you use as a charger, just a wide input range USB charger? It’s outside automotive 12V range by a good bit, but not compatible with the 24V coach system chargers either.

DeWalt makes an adapter which supposedly has working LVD, but I use a cheaper off-brand “LANMU” one and just am careful not to allow it to fully drain the DeWalt battery.

I’ve been meaning to figure out how to mod the LANMU adapter to add a nice LVD, but haven’t gotten around to it yet.

The other downside to most of these adapters is that they don’t do fast-charging. Not a deal-breaker for me, but may be for other folks.

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Has anybody here run something like the Xtar PB2/PB2S? I have a growing number of things that run off bare 18650 cells, something that works as a combination powerbank and charger seems a handy idea.

I have… um… a lot.

Everything from 400w/h with built in mppt trackers to a couple of 10k ah (@5v dc) pocket size lipo packs.

‘fast charge’ is likely bad for cell life anyway.

probably about 10 and growing, since I learnt how to 3d design and print them. Currently using a lot of flat cells from laptops and tablets with such 3d-printed enclosures. Example.

That’s an interesting way to reuse the pouch cells! They’re certainly more common than 18650s in laptops anymore.

Do you just size an enclosure to whatever you’ve found?

One unfortunate thing is the board they link needs a cell that handles 4.35v charge OK.

Most modern cell phone or laptop cells will. However, doesn’t look hard to change the board out for one that only charges to 4.2V, and for a power bank, you probably want to do that. Putting lower than rated voltage into cells is a great way to improve longevity if they’re spending most of their time fully charged. If I could find a board that did 4.1V, even better!