What to do with all the 18650 that are about 500 mAH

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Jul 11, 2017
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After sorting through my 18650 batteries, I have a lot that end up as dead or around 500 mAH. Is there anything we can use the 500 mAH 18650s for? I don't want them to go to waste. Is there any benefit to adding them to my wall build in their own 80p rack?

Any Ideas?

Thanks,
 
Flashlights and toys that have leds and sounds (motors probably not so much)
 
HappyCamperHomesteader said:
Is there any benefit to adding them to my wall build in their own 80p rack?

Yes absolutely (if you enjoy soldering) .... If they can hold 100mAHrs and don't self dischargeI would use them , but keep them in a separate pack
 
Personally, I would just use them with a low voltage solar panel along with a low wattage LED(1W) for outside/emergency light.
 
Yeah I have the same issue, I put anything less than 1000mah aside because I have no real use for them. I have quite a few and No real use for them.
 
Everything below 500 here is thrown back to the recycler
up to 800 for just experiements and blow them up. 800-1300 simple toys. 1300-1800 atv and other things. 1800 and up goes to powerwall like stuff.
 
I'm using some of my low-cap cells here, instead of two AA batteries :D . Have about ten of those in the house, just added a battery holder and a voltage regulator. With a 1000mAh cell, it works about 6 weeks:


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AveRageJoe said:
Damn that would be AWESOME!!! To bad I dont have a crap ton of the same cells. Ill have to see what I got cause a charge controller is all thats holding me back right meow.

Sorry, by "same cell" I didn't mean same exact model. This is the first time I did that. The normal grouping I use are "Sanyo Heaters", "0v Cells", then usually I'll group the low capacity cells to something like 1000-1500, 1500-1999, etc.
 
mike said:
AveRageJoe said:
Damn that would be AWESOME!!! To bad I dont have a crap ton of the same cells. Ill have to see what I got cause a charge controller is all thats holding me back right meow.

Sorry, by "same cell" I didn't mean same exact model. This is the first time I did that. The normal grouping I use are "Sanyo Heaters", "0v Cells", then usually I'll group the low capacity cells to something like 1000-1500, 1500-1999, etc.
Ok well I might give it a try once so I can get to using my "Power Rack". Im not looking to compete with anyone else sellin there stuff. Thats not my intention at least. Thanks Mike [emoji106]
 
I'm toying with the idea of making a 3360 battery bank 14s240p because I have so many 18650s that have about 500mAH capacity. I'm wonder if 240 batteries in parallel will last long enough to be a productive battery bank (even though they only hold about 500mAH capacity)?

What do you think?

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HappyCamperHomesteader said:
I'm toying with the idea of making a 3360 battery bank 14s240p because I have so many 18650s that have about 500mAH capacity. I'm wonder if 240 batteries in parallel will last long enough to be a productive battery bank (even though they only hold about 500mAH capacity)?

What do you think?

image_dzpxfj.jpg

Its possible because the pack will be so big. The amp draw would be TINY!!!
 
It's possible that you might actually get more than 500mAh in practice because your amp draw will be so low. It'd be like getting the full capacity of a cell without it having voltage drop. There's usually a little capacity loss due to voltage drop when pulling a load. In this case, that load wouldn't cause the drop in the first place. (I'm guessing; even if it does, it'd be in the mV range)
 
I'm thinking about it giving it a try. The only cost to will be the fuse wire and the plastic cell holders. If this works I'll probably do the same thing for all the other cells I have that are around 1000mAH.

Next question I have is the number of 18650s in parallel. Is 14s240p actually a waste of space and cells? I wonder if I can achieve the same results with less cells (my only requirement is to produce 48V for my inverter)?

I'm trying to guess the optimum number of 500mAH cells in parallel to produce a productive battery bank. I believe you are correct that given enough cells there will be no loss because of the small draw on each cell.

Any ideas about the optimal number of cells I should use in parallel?

Thanks
 
Personally, what I'd do, is build each small 48V pack. Then start connecting the packs in parallel. This way you will have lots of flexibility and if you need to add more, it's easy to do. Now, you could do a few series in parallel in a pack. Say, 14s4p = 56cells/pack; 2000mAh/pack. Doesn't seem like a lot, but then you start adding the packs in parallel. So, if you had 10 packs, you'd have 20Ah; and you can continue to add packs till you run out of cells (which, in this line of work, is virtually endless atm)

But that's my .02 worth
 
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