Lithium batteries, fires, and possible paranoia - Page 1
Forum section: electronics / general

author: Infraviolet
author_rank: Super Contributor
timestamp: March 13, 2022, 02:25:23 pm
content: I've just realised quite how many aging LiPos I have around the house in seldom used devices. Things like spare laptop batteries, never used since bought. Li 5V powerbanks, used a few times since bought but mainly stored away incase I should find a use for them someday. Spare phone batteries, and the odd little rarely used gadget with an inbuilt LiPo. They're all several years old, and many haven't been charged in several years (though would have been at 50% to 100% charge when out away). Some are brand new as purchased, some of those inbuilt are on second hand devices.These are all in seldom used things, but I'd rather not just throw them away if they are in working order.They're also all, assumedly, reasonably reputably made, and probably have inbuilt protections, so not the big RC car style cells.Except the phone batteries none have the cell itself visible, so I can's see if any may have subtle bulging (clearly none have enough bulging to pry open the casings).I don't know for certain how the second hand devices were treated by previous owners, but everything else has been free of being electrically or mechanically abused, except for being left very long periods of time without recharging.The thing is I'm a bit paranoid about lithium cells, having read much about their failure modes some years ago, and opted as a consequence of that not to put an Li based battery in the project I was designing.I'm wondering what the best place to keep these batteries is, so that if they spontaneously ignite while lying around the flames can't spread. I'm mainly thinking of the risk of them setting things alight while I'm not around.I know of lithium battery bags, but I think they just contain some of the flames, yet let enough hot gas and such leak from their vents that if the batteries are in a store pile near things like books and cardboard then those papery things can be ignited.I've also seen videos of storage in ammo cans or other sealed metal boxes, where a battery going off blew the entire thing apart and threw flaming fragments everywhere.Would I be best to maybe use battery bags inside a screw tightened metal box or something? What else could I do so if the batteries decide to ignite some day they can't set light to anything else around them. And no, I don't have a shed or garage to leave them in where there would be nothing around which mattered if they did go bang.

author: rstofer
author_rank: Super Contributor
timestamp: March 13, 2022, 05:49:25 pm
content: In my case, I have to park my Chevy Bolt in the driveway, never in the garage and not on a hill (unless hill mode is selected) until GM finally replaces the batteries. I think they're hoping the car dies of old age before they spend money on fixing it.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 13, 2022, 06:37:01 pm
content: Li-ion batteries are still problematic as far as safety is concerned, however we look at it. They're not all made equal, certainly, but problem is, you don't always know.And, whether they are very well constructed or not, the chemistry is still fundamentally unsafe. It's prone to catching fire, and since they pack a relatively high energy density, that just makes things worse.As to old batteries that haven't been charged in years - I would just dispose of them. If you absolutely don't want to waste good ones, what should be done would be to check them every few months, possibly recharge them a bit (I think keeping them around 50% SoC for long-term storage is reasonable) before putting them back to storage. The ones that have dropped below 3V or even 3.2V, I would get rid of them.Bulging is a bad sign indeed, but unfortunately that's something you can see only with the soft pouch cells.

author: Infraviolet
author_rank: Super Contributor
timestamp: March 16, 2022, 11:36:10 pm
content: Issue for checking voltages, and observing bulging, is when you've got battery cells within a sealed pack you can't get an individual cells to measure the voltages, or to see if there is any bulging. For a phone type battery you can check this, but for a laptop battery or USB powerbank the cells are hidden behind glued-shut casings and the voltages hidden behind output regulators.Wish Li wasn't quite so popular, that said I might have a go at making a USB powerbank with NIMH in it, those I trust not to go boom, even if they are a bit weighty.

author: G7PSK
author_rank: Super Contributor
timestamp: March 20, 2022, 03:32:17 pm
content: I do not worry about lithium batteries any more, I have seen the ones on you tube explode or burn when punctured etc but all the ones I have tried this with have not done anything so dramatic. I have put nails through them, shot them and pounded them with hammers but nothing other than a punctured or deformed battery, both pouch type and metal cased. I have even tried grossly over charging them without them catching fire, I once connected a single 18650 across a car battery and the only casualty was the wires connecting the two which got hot and burnt through. So to my mind the dangers from well made lithium cells s rather over rated.

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: March 20, 2022, 04:00:14 pm
content: How bad the fire is depends on the battery size. The ones found in most phones etc. likely won't set fire to nearby items, just release some steam and maybe spill electrolyte. The phantom power draw from the BMS on most packs would eventually drain them. I have a bin full of RC lipos (no BMS), some bulging, but all were stored in a discharged state.Quote from: rstofer on March 13, 2022, 05:49:25 pmMay want to check with your dealership, GM contacted me a couple of weeks ago and asked to bring mine in for inspection. This coming week I'm getting a new battery, and reports online indicate the replacements are 64 kWh instead of 60.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 20, 2022, 07:08:12 pm
content: Quote from: Infraviolet on March 16, 2022, 11:36:10 pmYou could consider LiFePo4 instead, which is much safer while having a higher energy density than NiMH.

author: coppercone2
author_rank: Super Contributor
timestamp: March 22, 2022, 01:27:47 pm
content: Quote from: G7PSK on March 20, 2022, 03:32:17 pmwhen I crushed it with a hammer through a 18650 it went off like a rocket engine. Took maybe 6 good whacks with a 6 pound maul before, as expected, there was about a 3 foot long high thrust fireball and a 'oh shit' from the neighbors. I put it so it fit tight into a crimped pipe that I stuffed into some rocks to 'direct' the flame. Think about when they activate the thruster in one of those modern planet of the apes movies from the 2000's. The fire lasted about 1.5 seconds and left the cell looking 'roasted'. If I did not have the cell seated in the apparatus to direct thrust and anchor it then it would have flew away like a CO2 cartridge filled with acetylene.I made big NiMH batteries with banana jacks and fuses on them after that lolI would rate your experience as deceptively lucky. OP, I would say you DO have a point. Good to at least monitor those shitty devices for bulging. No shame in alkaline/NiMH for a good nights sleep IMO.