How to charge long batteries? 90mm and longer

I am testing a flashlight with a very long battery (46120)… But the flashlight has onboard charging, which is very slow.
What do you use to charge larger batteries?

I was thinking about buying one of those RC chargers that charge Lipo batteries etc.
Then get an XT60 female cable, and build some connectors to some type of clamp, and then tighten the clamp to charge a battery.
I could use this for other types of batteries as well (46950), including my son’s RC car’s Lipo battery that is currently charging with a cheap USB charger.

Some of these RC chargers can also charge other battery types, and at different voltages. (1S to 6S).
Plus, they can charge at a much higher charge rates than normal chargers (up to 15A).

But perhaps there is something out there that holds longer batteries… or a special charger.

Magnets. Use them to connect wires with the charger and battery terminals.

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That’s definitely an option. You were not afraid of them touching by accident when connected?

Olight used to make the best magnet charger, but last I checked it’s been discontinued… I suspect the charging current would have been too low for your requirements anyway.

Id go with an RC charger and build a custom cell holder to charge it, you could probably 3D print something really nice.

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FYI, the Olight magnetic charger (well, the 4/7s version) is available from 4/7s. It’s a great charger to have around, although you’re right in this case I’m sure the current would be too low.

edit- after checking the site to provide a link, I don’t see it available anymore. Disappointing, it’s a great product.

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Maybe fireflylite magnetic charger will work instead?

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I actually have the Four Sevens magnetic charger, but I need something more powerful :smiley:
Right now onboard charging is at a maximum of 22 watts, 12.XV, 1.7XA
I think the magnetic ones can only do 1A?, at 5V. or around there.

Ideally I need something to charge at 10A and 5V, or better, 10A and 12V :smiley:

The battery I am trying to charge is supposed to have 42,000mAh
Which is ridiculously large.

I’ll continue my search for an RC charger, with some XT60 plugs+cables, and then make my own.
If anybody has any better/other idea, don’t feel hesitant to share.

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I use an Accucell 6 for charging batteries that don’t fit well in my other chargers. I connect the ends of the charger’s leads to the battery’s terminals with magnets.

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That’s probably what I will also do, if I can’t find anything else.

Edited this post a few times with new findings :

I found a few intresting holders… Now I have to dive a bit deeper, but this is likely what I’m after + RC charger & cables.
This is made by Gamry


I found this, which is available on Amazon

And some on Alibaba

and this one

This one on Amazon.in

I think now we’re coming close with this one: This says it’s a 4680 battery tester

And Aiexpress; YR1030, YR1035 zubehör 18650, 26650, 32650 zylindrische batterie test stehen - AliExpress 1420

And this: 5a (max 10a) 4-Draht-Prüfstand Batterie halter clip für 26650/18650 aa/aaa/Knopf batterie (Batterie nicht im Lieferumfang enthalten) - AliExpress 1420

And this one on Aliexpress… supposedly 15-20cm :smiley:

These look promising.
Now I need something that is like 150mm / 15cm long… perhaps 130mm might be enough

I made something similar myself:

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I saw your picture earlier… and it’s nice how easy it is to tighten it.

I have some of the 3rd holders from Vapcell.

Perhaps you could use a bench power supply with a holder.

Or as was originally mentioned a hobby charger. Which has built in algorithms for all of the common cell types. I have been using one of those for 26800 cells for quite a while.
BTW, I use cube magnets 1/4" (about 6 mm) on a side. N52 magnets. Theystay on the cells very well. Then alligator clips once they are on the cell from the banana plugs/sockets on the charger… No problem with the magnets shorting out with leads attached… As long as you disconnect them from the clips, of course.
I can charge at 3 amps with these without problems. Probably could go higher, but I have not tried.

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Nice… I contacted Vapcell to see if they can sell these ‘adapters’ through Aliexpress… Dennis replied they can sell them, but waiting on how to go forward.
They have them on Alibaba, but not on Aliexpress (yet).

I got lost… What adapters are you thinking of?

Be careful with cell length. I have quite a few different holders for measuring IR. Not all of them will fit even 21700 cells.

sorry, I just wanted to reply to the thread :smiley: and not directly as a response to your post. Vapcell sells one of these adapters on Alibaba, so I reached out to Dennis to see if he can sell it on Aliexpress.

Vapcell also have a direct webshop, no? Id be interested to see these holders, I couldn’t find the Alibaba link

Good question. I didn’t know they had their own e-store. I used Google Image search to find these adapters.
I just visited their online store, but couldn’t find these adapters.