Advice on li-ion battery controllers

Tags: #<Tag:0x00007fa49b1ecf48> #<Tag:0x00007fa49b1ece08> #<Tag:0x00007fa49b1ecc78> #<Tag:0x00007fa49b1ecb38>
#1

With the rapid rise of single use nicotine vaporisers, the number of li-ion cells being thrown away is quite depressing.

I had an idea to collect a bunch and use them to power a boombox.

I sadly have no electronics experience and so wondered if anyone can point me in the direction of resources to learn about the techniques and requirements for safely charging and discharging li-ion, and where I might purchase battery controllers.

From what I understand already, I would need to:

  • ascertain the specifications of each cell
  • arrange them in such a way to match the voltage requirements of the system
  • have control over both the charging and discharging profiles for safety (overvoltage protection)
  • have temperature sensors linked to cut offs

If anyone has any advice I would greatly appreciate it!

Cheers, Felix

#2

Hint have a bucket of sand on hand.

2 Likes
#3

What are your requirements? It will be more difficult to charge them if you have 2 or more cells in series.
Since you are salvaging cells, having matched cells in series will be a challenge since they come from different manufacturers.
Also, as far as I understand, the vapes generally use LiPo cells, that are far easier to puncture relative to LiIon with metal casing (18650, 21700).

#4

It is really hard to give you an advice here without it being unsafe, because it would be to short to be complete.
Battery controllers with right profiles (read: tp4056/ tp5100) and protection are dime a dozen, but

  • You cannot really ascertain specifications of anything you found lying on the streets. It is not repeatable outside a factory. Any two cells you find are different. Some of them will be damaged before you test them. Some straight after.
  • You cannot connect these cells in parallel, current will flow from one to another and they will overheat.
  • You can connect them in series. However, you should not balance-charge them as cells may be too different for balancer (same as parallel connection).

Your best bet is try charging them individually. Bucket from above may prove handy.

1 Like
#5

You can connect them in parallel if all of them are properly discharged. If you want to be extra safe, you can use a parallel battery charging board that comes with automotive fuses and PTCs.
However, it is the cheapest pouch cell the vape manufacturer could find and the requirement is it has to last one cycle. I think this is the main risk.

#6

properly discharged

You are assuming none of them are damaged internally on a brink of fail.

1 Like
#7

That’s my point as well, they are dodgy pouch cells, maybe you charge them and they go boom, maybe you discharge them and they go boom, maybe you press them too hard and they go boom.

1 Like
#8

The mission is admirable, but there are two problems as a few people raised:
A) I do not trust disposable vape batteries when it comes to Quality Control, nor the fact that they’ve probably been bumped around when being binned

Which leads into
B) Lithium cells are finnicky, fragile, temperamental and most critically, very explosive. The margin for error is narrow and the last thing you want is a thermal runaway where one battery ignites the rest in an array. Bad times are to be had down that route.

#9

Powering a boombox is a bit of a stretch, you’ll probably find tutorials and videos online of people turning them into smaller things like emergency torches/bike lights.

Even then, if you’re not careful you risk over-discharging a cell which will also ruin the battery and make it swell.

If you want to do something good, you’re best collecting the batteries and putting them in a specialist battery recycling box that you can find in many supermarkets.

#10

You can balance cells by connecting them together with a suitable resistor so that one discharges into the other at a safe rate until the voltages are equal. You should then be able to wire them in parallel.

#11

Thank you all for the input this is all very interesting. So in summary:

  • LiPo not Li-ion
  • low quality & not designed for multiple cycles
  • high risk of fire & explosion

That make them quite unsuitable for long term reuse.

Perhaps I’d be better using the time to lobby their ban (vs reusables) !

Thanks again for the help. Onto the next idea…

1 Like
#12

I’ve never heard this about the cells being only designed to survive one cycle. Does anyone have some literature to back that up or are people just being very cautious? Is it really significantly cheaper to make a cell that won’t survive being recharged than one that will, considering the market for cells that can be recharged?

The abandoned vapes I’ve found are in stout plastic cases or aluminium tubes. I don’t see how the cells could be physically damaged without abuse of the case being obvious.

#13

Not my proudest moment but I once accidentally dropped my vape into my pint and it started getting very hot very quickly - I’d imagine if they’ve been out in the rain there could be something similar going on with the ones you’ve found.

#14

I have no specific knowledge around this particular case, but in any kind of manufacturing with some sort of quality control you get products that don’t pass. And sometimes these products can be repurposed for another application that’s not so demanding.

So I wouldn’t be surprised if there are batches of batteries that don’t pass quality control for whatever reason, but get used in these vapes because the manufacturers don’t have to worry about the vapes being recharged.

It would be interesting for someone to collect and test a bunch of these batteries to prove or disprove that they’re lower quality, but you’d need to do this in a lab, in controlled conditions, and with good fire suppression measures :wink:

#16

My guess there is that liquid got into the controller (with the air pressure sensor) and caused it to switch on the heating element permanently. This would have both caused the reservoir of liquid to overheat (through time and through no air flowing through it) and possibly the battery, which wouldn’t be rated for continuous discharge at that current. No reflection on the quality of the battery if used within its operating parameters. Your drink wouldn’t have got inside the battery itself, and as it’s only 3V, little current would have flowed directly between its terminals through the drink.

(Edit: sorry about the withdrawn post - I thought it hadn’t replied properly to yours.)

I haven’t got any vapes to had to measure, but my guess is that the current taken by their heating elements is quite high compared with the capacity of the battery, and therefore this is quite a demanding application. Of course there could be other issues with the cells, like they just don’t have the capacity claimed, but I’m still not really convinced that there is a safety issue in particular with these cells.

#17

Oh yeah 100%, was just trying to illustrate how far outside of normal operating parameters some of these batteries have been pushed :smile:

1 Like
#18

Have any of you seen BigClive on YouTube about this? He gives some great advice on how to use these batteries safely. He recommends using charge control boards and USB Powered boards that look after charging, preventing over charging, over current situations and they also prevent over discharging as well.
I have collected literally over a hundred of this LiPos from discarded vapes (remember to stay hygienic) and have several that have been through dozens of charge/discharge cycles. Simple controller boards are available on eBay for pennies each (in 10’s). I’d suggest that to use them in a BoomBox you’d need to use them in Series and parallel with an appropriate controller board from the internet.

1 Like
#19

This one?

#20

Yes - that’s the fella. He has lots of informative videos including several about re-using Vape cells the right way. He seems pretty clued-up about electronics safety in general and so, if he’s happy to reuse them so am I. I have a couple of project ideas that could utilise a rechargeable cell such as these. I’d only use cells from intact vapes and not any that have been run over by cars or found in puddles.

1 Like