What battery to choose after your last one burned your house.
- Thread starter dogman dan
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krlenjuska
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armandd said:
Can you recommend some good 6S BMS?
liveforphysics
100 TW
flippy said:
Nissan LEAF = A pouch cell pack >369,000 vehicles on the road. A single battery fire event reported.
Tesla Model S = 18650 cell pack >243,000 vehicles on the road. 14 reported battery fire events.
The cell type is irrelevant. The internal cell chemistry is largely irrelevant (but slightly effects).
If you design/package a pouch or 18650 pack poorly with respect to corrosion protection, vibration protection, busing insulation, management, it burns down all the same, the difference is if you hear popping sounds or whooshing sounds as it goes.
flippy
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the leaf is a quarter of the size of a a tesla pack and can deliver only a fraction of what the tesla pack can do. the tesla's also have driven a LOT more then leafs and due to the nature of the car are also more suseptible to "driver induced events". often you will hear such stories about a burning tesla but they forget to mention they hit a concrete or steel pole just before it caught fire.
i am not saying tesla packs are perfect or even inplying it. but considering when a event DID happen it happend in a very controlled manner and with pently of time for people to vacate the car. or did you guys forget that richard hammond was almost burned alive when he crashed the rimac and the pouches went nuclear almost immediatly?
its logical to expect batteries to fail due to whatever reason. but beware for people just out for getting his 5 min of fame.
otherwise you get these kinds of assholes: https://bgr.com/2018/12/17/tesla-fire-battery-pack-lawsuit/
a tesla catches fire after hitting a block of ice on a frozen lake, when was the last time you saw a leaf doing burnouts and slides over a frozen lake?
yup, highly dangerous stuff. before or after shooting it? what will be more "eventful", a 18650 cell holding 11Wh or a leaf pouch holding almost a kWh going instantly thermal?
despite the fact a tesla pack is the biggest and baddest out there i still have to see a case where a driver/passenger died because the battery burned to fast he could not get out, ignoring the morons that wrapped their car around a tree at 150mph ofcourse.
id love to see a tesla sized leaf battery go thermal after hitting a wall at 100mph. (ignoring the fact a leaf cant even hit 100mph...)
i am not saying tesla packs are perfect or even inplying it. but considering when a event DID happen it happend in a very controlled manner and with pently of time for people to vacate the car. or did you guys forget that richard hammond was almost burned alive when he crashed the rimac and the pouches went nuclear almost immediatly?
its logical to expect batteries to fail due to whatever reason. but beware for people just out for getting his 5 min of fame.
otherwise you get these kinds of assholes: https://bgr.com/2018/12/17/tesla-fire-battery-pack-lawsuit/
a tesla catches fire after hitting a block of ice on a frozen lake, when was the last time you saw a leaf doing burnouts and slides over a frozen lake?
yup, highly dangerous stuff. before or after shooting it? what will be more "eventful", a 18650 cell holding 11Wh or a leaf pouch holding almost a kWh going instantly thermal?
despite the fact a tesla pack is the biggest and baddest out there i still have to see a case where a driver/passenger died because the battery burned to fast he could not get out, ignoring the morons that wrapped their car around a tree at 150mph ofcourse.
id love to see a tesla sized leaf battery go thermal after hitting a wall at 100mph. (ignoring the fact a leaf cant even hit 100mph...)
dogman dan
1 PW
The pack that burned my garage was being charged at the time. It had been behaving fine, which is why I suspect a bms failed. I suspect it let a cell group overcharge to the point it went thermal.
Generic no name cells from the cheapest vendor in china in that 18650 pack. Insurance company wanted to sue, but in china, and the company had vanished. They sold on ali express for a few months only.
I see no point in keeping them inside anymore, since they must charge outside from now on. But I agree, pretty damn safe to store cells at 30% state of charge. But then you can't ride very soon in the morning.
Pretty warm storage all summer, but a few less cycles beats the hell out of another year in the shitty rental house, while a contractor tries to rip me off every day on the remodel. But I'm simply done taking chances. When I travel in the RV, the cells will be on the rear carry rack of the trailer, in an ammo box.
Generic no name cells from the cheapest vendor in china in that 18650 pack. Insurance company wanted to sue, but in china, and the company had vanished. They sold on ali express for a few months only.
I see no point in keeping them inside anymore, since they must charge outside from now on. But I agree, pretty damn safe to store cells at 30% state of charge. But then you can't ride very soon in the morning.
Pretty warm storage all summer, but a few less cycles beats the hell out of another year in the shitty rental house, while a contractor tries to rip me off every day on the remodel. But I'm simply done taking chances. When I travel in the RV, the cells will be on the rear carry rack of the trailer, in an ammo box.
Philaphlous
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I'll throw my 2 cents in here...
I built a "cheap" pack over a year ago..more like 2 from laptop cells...some new some old. I tested most of the cells and they came out to be right around 2000mah at 1 amp discharge. Well I beat the crap outta them and was regularly pulling 5A from these cells... Took the old pack apart a month or so ago and low and behold I only got about 500mah in a 4A discharge...when in the exact same tests for the Panasonic cells I was still getting at least 2200mAh... Im surprised the cells just didn't fail right away. The sag was so bad at 4A per cell I was looking at like 3.4V after a full charge when put under that load...
I'd say that new cells are a must. Or at least old stock of reputable cells is fine. Fortunately I found a dealer to get all panasonic cells which are the same ones in the Tesla roadster and these are great now! So much more capacity and I feel 100X safer. Also preventing there from any sort of physical damage to the pack is another must. I started to dent one of the cells because it was just hot glued and duck tapped together...not good. Now I've got all these dumb cells sitting on my desk that I need to dispose of.....what a waste.
I built a "cheap" pack over a year ago..more like 2 from laptop cells...some new some old. I tested most of the cells and they came out to be right around 2000mah at 1 amp discharge. Well I beat the crap outta them and was regularly pulling 5A from these cells... Took the old pack apart a month or so ago and low and behold I only got about 500mah in a 4A discharge...when in the exact same tests for the Panasonic cells I was still getting at least 2200mAh... Im surprised the cells just didn't fail right away. The sag was so bad at 4A per cell I was looking at like 3.4V after a full charge when put under that load...
I'd say that new cells are a must. Or at least old stock of reputable cells is fine. Fortunately I found a dealer to get all panasonic cells which are the same ones in the Tesla roadster and these are great now! So much more capacity and I feel 100X safer. Also preventing there from any sort of physical damage to the pack is another must. I started to dent one of the cells because it was just hot glued and duck tapped together...not good. Now I've got all these dumb cells sitting on my desk that I need to dispose of.....what a waste.
Chalo
100 TW
Philaphlous said:
A waste of your time, I suppose-- except to the degree that you learned some valuable things that way. But if I'm not mistaken, your laptop cells were already somebody else's garbage when you got them. So that part can't really be characterized as a waste, can it?
999zip999
100 TW
Take those old cells and put in the backyard BBQ. New cells only name brand cells. I bought 35 Makita tool packs or 350 Makitne cells the seller can only find 27 Packs. The next day he found the rest to fill my order. I open the top on one and fire shot out the top of one cell. Happen 5 times more. No use cells. These used Canadian return packs are drop in the frozen pond or worse and return to the factory. Just like gambling on a cheap Chinese battery pack.
dogman dan
1 PW
FWIW, definitely have vent holes in the ammo cans I store the lipo in. I may not have been the very first to do that, but It was many years ago that I vented my cans. The ammo cans just seal too good.
Before the fire, my lipo did get stored inside, inside my fireplace, with those vent holes pointing into the firebox.
During the remodel, we took out the fireplace. Good thing too, it was so improperly installed that the wall framing was scorched black behind the thing. I gained the old fire damaged kitchen stove in the remodel, so that became my lipo bunker. Its in the backyard, close to a steel shed, but far from the house.
The real reason I burned my house was very simple. While I never trusted the lipo, I trusted the 18650's. You got them on your desk? Get a bunker for them, or discharge and dispose them.
Before the fire, my lipo did get stored inside, inside my fireplace, with those vent holes pointing into the firebox.
During the remodel, we took out the fireplace. Good thing too, it was so improperly installed that the wall framing was scorched black behind the thing. I gained the old fire damaged kitchen stove in the remodel, so that became my lipo bunker. Its in the backyard, close to a steel shed, but far from the house.
The real reason I burned my house was very simple. While I never trusted the lipo, I trusted the 18650's. You got them on your desk? Get a bunker for them, or discharge and dispose them.
krlenjuska
10 W
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dogman dan said:
Is there any easy way to add smoke detector to battery case? Or any other alarm system - temperature or something else.
Sure.
Put any battery powered smoke detector on there. You can get them at home improvement stores, and probably a lot of other places, and of course, the interwebs.
There are probably also plenty of battery-powered thermal alarms out there.
The smoke detectors are also available in networkable / AC-powered (battery backup) versions, such as those in my house (so if one goes off, they all do...though the installers never hooked them up (at least, not correctly), so mine only run off of batteries). I think mine are "First Alert" brand.
Put any battery powered smoke detector on there. You can get them at home improvement stores, and probably a lot of other places, and of course, the interwebs.
There are probably also plenty of battery-powered thermal alarms out there.
The smoke detectors are also available in networkable / AC-powered (battery backup) versions, such as those in my house (so if one goes off, they all do...though the installers never hooked them up (at least, not correctly), so mine only run off of batteries). I think mine are "First Alert" brand.
SniperGaulois
10 kW
The PTC in Panasonic are pretty effective. Try shorting a panasonic from 2019.
SniperGaulois
10 kW
Good info flippy! I tried to find a PTC specification from a top 18650 company which states PTC limits and statistics, that's the most information I have for the moment.
I remember when liveforphysics sorted this out many years ago.
The one really impressive cell in his tests were the ungodly heavy headways lifepo4 cells. But who wants those on their bike? worse than a ping..
18650s and pouch cells contain the same flammable elements and respond the same when abused.
If dogman hadn't made up his mind already.. i'd say wait on the choice, because solid state batteries seem to be really close. There is at least one factory in China producing them today, and a couple other companies claiming they will be producing them in 1-2 years.
Solid state cells should be extremely safe compared to today's lithium. The first generation cells will probably be unimpressive in terms of the whrs/kg gained from the new technology, and they may be rated at a measly 1C at first, but by god, all indications are that these will be extremely safe cells.
I'm personally waiting and nursing my ~200whrs/kg 18650 packs in the meantime.
The one really impressive cell in his tests were the ungodly heavy headways lifepo4 cells. But who wants those on their bike? worse than a ping..
18650s and pouch cells contain the same flammable elements and respond the same when abused.
If dogman hadn't made up his mind already.. i'd say wait on the choice, because solid state batteries seem to be really close. There is at least one factory in China producing them today, and a couple other companies claiming they will be producing them in 1-2 years.
Solid state cells should be extremely safe compared to today's lithium. The first generation cells will probably be unimpressive in terms of the whrs/kg gained from the new technology, and they may be rated at a measly 1C at first, but by god, all indications are that these will be extremely safe cells.
I'm personally waiting and nursing my ~200whrs/kg 18650 packs in the meantime.
ElectricGod
10 MW
I know battery fires are possible, but despite abusing them a few times to see what would happen, nothing ever happened.
I've dead shorted single 18650 cells that were fully charged, over charged them to 4.5 volts...all that happened is they got hot. Same for LIPO, except those cells bulged.
I had a bunch of LIPO cells that were near end of life. I charged several of them to 100% and then drove a nail through the cells. All I got was some minor fizzling and some tiny whiffs of smoke. Over charging them had the effect of making them hot. Driving a nail through the over charged cells produced small whiffs of smoke and some sizzling sounds. These were 8000mah cells.
Maybe my problem with complete failure to get fire is I wasn't trying to destroy a complete pack, just individual cells and so heat had no chance to build up sufficiently? I don't know, but I'm not willing to blow the money in an investment like that to find out.
I'm not operating in fear either. I'm not even slightly concerned about burning my house down. I've been using LIPO and LION chemistries for 15 years and the worst problem is a few whiffs of smoke when I deliberately destroyed cells. That doesn't seem like a very big risk to me. The gas cans in my garage are probably more dangerous. The open parts washer that has gas and kerosene in it that I use for washing parts is probably way more dangerous! One spark with those fumes and WHOOM!
I've dead shorted single 18650 cells that were fully charged, over charged them to 4.5 volts...all that happened is they got hot. Same for LIPO, except those cells bulged.
I had a bunch of LIPO cells that were near end of life. I charged several of them to 100% and then drove a nail through the cells. All I got was some minor fizzling and some tiny whiffs of smoke. Over charging them had the effect of making them hot. Driving a nail through the over charged cells produced small whiffs of smoke and some sizzling sounds. These were 8000mah cells.
Maybe my problem with complete failure to get fire is I wasn't trying to destroy a complete pack, just individual cells and so heat had no chance to build up sufficiently? I don't know, but I'm not willing to blow the money in an investment like that to find out.
I'm not operating in fear either. I'm not even slightly concerned about burning my house down. I've been using LIPO and LION chemistries for 15 years and the worst problem is a few whiffs of smoke when I deliberately destroyed cells. That doesn't seem like a very big risk to me. The gas cans in my garage are probably more dangerous. The open parts washer that has gas and kerosene in it that I use for washing parts is probably way more dangerous! One spark with those fumes and WHOOM!
markz
100 TW
The LiMn chemistry is pretty safe.
https://endless-sphere.com/forums/search.php?keywords=LiMn+safe&terms=all&author=doctorbass&sc=1&sf=all&sr=posts&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
You could even pot your battery, like what Justin does to their LiGo branded battery.
I would suggest you build your own pack or buy from reputable supplier, like www.ebikes.ca and EM3EV, Unit Pack Power. Atleast when you build your own pack, you know exactly how its built. Then when another battery is needed, you save even more money! because you already have the tab welder!
https://endless-sphere.com/forums/search.php?keywords=LiMn+safe&terms=all&author=doctorbass&sc=1&sf=all&sr=posts&sk=t&sd=d&st=0&ch=300&t=0&submit=Search
You could even pot your battery, like what Justin does to their LiGo branded battery.
I would suggest you build your own pack or buy from reputable supplier, like www.ebikes.ca and EM3EV, Unit Pack Power. Atleast when you build your own pack, you know exactly how its built. Then when another battery is needed, you save even more money! because you already have the tab welder!
markz
100 TW
armandd said:
Ya but how does one know they have a good BMS?
markz
100 TW
I just had an idea, find an appropriate steel gauge, for lightness yet thick enough. Make your battery box out of that, instead of using ammo can.
Better yet....
Build an ebike that encapsulates the battery and is apart of the frame, yet your can slide it out. That would deal with corrosion issues as LiveForPhysics shared, deal with protecting from physical damage from falls, and protect you from your bad experience.
Better yet....
Build an ebike that encapsulates the battery and is apart of the frame, yet your can slide it out. That would deal with corrosion issues as LiveForPhysics shared, deal with protecting from physical damage from falls, and protect you from your bad experience.
tomjasz
1 GW
Another report of a UPP, Unit Pack Power battery up in flames.
Matador
100 kW
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armandd said:
In my experience, BMS quality is almost universally overlooked. We assume that "just as long as you have a BMS, you're good... Regardlrss of the quality".
There is NO BENCHMARK to compare the rpos an cons of BMSs. nobody knows enough about them. Buying a BMS is a gamble .... Maybe that praised supposedly "high quality BMS" will fail and burn down your house, maybe this super cheap low quality BMS will do its job perfectly well forever protecting you.
The average neophyte who builds a lithium battery has no way to tell what quality bms he is buying. I challenge you to prove otherwise.
I can tell balance currnet, max current and all that... But i can't tell is one of the component will fail after a month or never.
For computers, we have website tat give CPU benchmark tables so you can tell which one is the best performing CPU.
Same thing for GPU.
The website raank them from first (best) to worst.
Why can't we have the same thing for BMSs ????
EV are now mainstream enough that their should be such a ressource for gauging the quality of the BMS your buying...
