What battery to choose after your last one burned your house.

[e-beach]

Yea, I have been thinking about those TO cells in a bike application. My cursory calculations are something like a 80 to 100 LB bike. The battery pack could be 48v and 40ah (20s 1p) and could travel around 75 miles with a maxim output of 400 amps to the controller. It could be fully charged in 6 minutes if one could supply 400 amps to the cells without frying the controller and or BMS. (That would be like needing 7 cycle satiators in parallel.) As of today, the cells would cost around $1200 USA and would last for something on the order of 50 years if they were used for one full cycle each day of the year for 20,000 cycles.

It could be a nice bike, although heavy.

 

[999zip999]

In 3 years batteries will be 5volt and higher ah.

 

[e-beach]

Are you speculating or do you have proof?

 

[999zip999]

Dreaming of the future. No dreams no future.

 

[Skaiwerd]

Any thoughts on these Panasonic batteries? Picked up 280 from a recycling bin at work. They are in packs of 20 for 24 volts with a date of only a few years old. I will post actual pack photo soon. This looks like the data sheet.

https://www.digchip.com/datasheets/download_datasheet.php?id=3683005&part-number=HHR-450A-1Z

At around $10 each retail I’d hope they are usable.

 

[e-beach]

My first impression is that you will need a lot of cells to make a good battery. Like 600 cells maybe? I looked at the data sheet and could not determine what the maximum continuous discharge would be. Somebody correct me if I am wrong, but maybe .5C? Like 2 amps per cell?

So in my mind it would go like this: 48v divided by 1.2v is 40 cells. So you would need 40 cells in series to make a 48v battery.
To have something like a 30 amp discharge, then you would need 15 cells in parallel.
So a 48v battery with a 30 amp discharge would have to be 600 cells, (40s15p)

With your cells I would discharge them all the way and then recharge them, and then discharge them through a watt meter to check for actual capacity.

 

[fechter]

Any thoughts on these Panasonic batteries? Picked up 280 from a recycling bin at work. They are in packs of 20 for 24 volts with a date of only a few years old. I will post actual pack photo soon. This looks like the data sheet.

At around $10 each retail I’d hope they are usable.

The problem with those is they don't like being put in parallel. During charging, toward end of charge the voltage actually drops, which could cause a thermal runaway if you have a bunch in parallel. I have seen guys do it successfully though. Make series strings and parallel the strings at the ends. Watch carefully during charging, especially toward end of charge. This is the same chemistry as a Prius battery. It is pretty safe.

 

[JNorth]

re: idea of storing battery in your oven (in house).....the problem is someone coming along and turning the oven on to 415 degrees to heat it up to cook a frozen pizza...without looking inside.

 

[999zip999]

When I was 19 we drove No Cal for a lb of weed then went out for Chinese. We got back and his sister wanted to make fudge brownies they turn the oven on and then mix it all together in the kitchen I'm in the living room when I start to smell something he hide the pound of weed in the oven and forgot about it. We almost lost 1,800 usd.
Richard always did knucklehead stuff

 

[amberwolf]

If it's electric, usually the oven/stove is on it's own breaker, so if you flip it off, and lock the breaker box with a padlock you have the only key for, it'll be difficult for that to happen.

If it's gas, the shutoff's petcock can be turned off at the wall (though this may be behind it and hard to reach, that will also be a further deterrent to turning it back on). (some old houses may have only the main shutoff valve, which turns the gas off everywhere...if you want to install individual shutoffs, this page has some details, though I couldn't say if it's the correct way, the information is still useful: http://xj.cdevco.net/gas_line/ ).

 

[Dui ni shuo de dui]

The safest big use ebike battery if fits. Would be an A123 20ah pouches ....

Wasnt it Fisker who used A123 pouches in their cars ?
..and didnt their whole busines fail when those pouches started to burn those cars up ?
Sure, i know it was tracked to a manufacturing fault at the A123 plant, producing a practically undetectable defect in the cell,....... but it still shows thar any cell can flame .
....and there are probably still thousands of those original A123 pouches around , selling cheap, somewhere.
So you have to be wary !

Not really what happened according to Wikipedia:

"The company suffered a setback on October 29, 2012, when Hurricane Sandy flooded and destroyed its entire European shipment of 338 Karmas at Port Newark, New Jersey.[30] Sixteen of the cars burned, because six to eight feet of seawater caused a short circuit in a vehicle control unit in one Karma, and high winds spread the resulting fire to 15 others.[31] The company said that its lithium-ion battery was not at fault."

https://en.wikipedia.org/wiki/Fisker_Automotive

Also:

"A Fisker Karma was involved in a home fire that also burned two other cars in Fort Bend County, Texas in May 2012. The chief fire investigator said the Karma was the origin of the fire that spread to the house, but the exact cause is still unknown. The plug-in electric car was not plugged in at the time the fire started and it was reported that the Karma's battery was intact. The carmaker released a public statement saying that there was uncertainty and conflicting reports surrounding the event. Fisker Automotive also stated that the battery pack "does not appear to have been a contributing factor in this incident."[71] The NHTSA is conducting a field inquiry of the incident, and is working with insurance adjusters and Fisker to determine the fire's cause.[72]

A second fire incident took place in August 2012 when a Karma caught fire while stopped at a parking lot in Woodside, California.[73][74] According to Fisker engineers, the area of origin for the fire was determined to be outside the engine compartment, as the fire was located at the driver's side front corner of the car. The evidence suggested that the ignition source was not the lithium-ion battery pack, new technology components or unique exhaust routing.[75] The investigation conducted by Fisker engineers and an independent fire expert concluded that the cause of the fire was a low temperature cooling fan located at the left front of the Karma, forward of the wheel. An internal fault caused the fan to fail, overheat and started a slow-burning fire. Fisker announced a recall to repair the faulty cooling fan unit.[65][76]"

https://en.wikipedia.org/wiki/Fisker_Karma#Fire_incidents

 

[dogman dan]

The only way to use those nimh, is to make a lot of packs that you connect only in series. Then parallel only for discharge. To charge, each pack separated again and charged with no parallels. Pain in the butt to charge. You got a lot of flashlight cells though.

Lots of ways to have a vehicle fire. I had a 65 international truck melt every wire under the hood, and in the dash. Big short on the battery wire to the alternator. Back then, so little plastic in the vehicle, it burned only wire insulation off. Now, any short can nearly consume a car, making it very hard to say where it started unless it is witnessed.

My bike fire was definitely the battery. We heard it popping cells, and when we ran to the garage to try to put it out, saw the fire involving only the battery area of the bike. But by then, the garage was just about to flashover, and we shut the door to the garage and started getting pets out of the house.

 

[Hillhater]

The safest big use ebike battery if fits. Would be an A123 20ah pouches ....

Wasnt it Fisker who used A123 pouches in their cars ?
..and didnt their whole busines fail when those pouches started to burn those cars up ?
Sure, i know it was tracked to a manufacturing fault at the A123 plant, producing a practically undetectable defect in the cell,....... but it still shows thar any cell can flame .
....and there are probably still thousands of those original A123 pouches around , selling cheap, somewhere.
So you have to be wary !

Not really what happened according to Wikipedia:

https://en.wikipedia.org/wiki/Fisker_Karma#Fire_incidents

Ok, so the defective A123 packs was not the main cause of Fisker fires or business failure, but many of their packs were defective and were replaced , both at Fisker and other pack customers (power storage etc).
So my point remains that there were, and likely still are, many defective A123 pouch cells on the used cell market.

 

[Dui ni shuo de dui]

Ok, so the defective A123 packs was not the main cause of Fisker fires or business failure, but many of their packs were defective and were replaced , both at Fisker and other pack customers (power storage etc).
So my point remains that there were, and likely still are, many defective A123 pouch cells on the used cell market.

Sure, but this doesn't have much to do with this thread, since none burned.
The packs were replaced because of performance degradation, not safety concerns.

The only incident who did ever occured was an explosion in the R&D center of GM, when some prototype batteries released gas who ignited in a closed, sealed chamber. The chamber blew out because of the huge pressions and injured employees, but the battery itself wasn't destroyed.

To my knowledge at least, none of their cells burned. So probably no need to be concerned that much.

 

[TheBeastie]

Well, its been two years now since the fire, and I'm finally going to buy a battery.

I really got tempted to go back to lifepo4, and get another pingbattery. But the low discharge rate, heavy, and large size still turns me off.

I came to the conclusion that what type does not matter all that much, since no e bike battery is ever going to enter my house or garage again. Storage is now in the old smoke damaged electric stove in the backyard

I was thinking maybe this story that just came out the other day about a Tesla owner might make you feel a tiny bit better.
Shows that it doesn't matter how much you spend you can still be unlucky with battery charging.

https://teslamotorsclub.com/tmc/threads/burnt-model-3.149655/#post-3581054
https://twitter.com/IAFF2878/status/1118533324492791809/photo/1
https://patch.com/washington/sammamish/sammamish-home-badly-damaged-fire-tuesday-night

If you got an industrial-strength equivalent "charging stove" in the backyard, you also have the option to then safely "low-amp/charge slowly" overnight, slow charging gives more battery cycles.

---------------------------------
*ADD/EDIT*
I think one of the weirdest most memorable moments I have had on Facebook/Twitter was about a good year ago where I said lithium batteries are quite flammable and shouldn't be considered any safer than combustion cars.
Back then there had been basically no Tesla/EV fires in mainstream media.
Someone jumped on and claimed I was the biggest moron in the world to believe lithium is anywhere remotely as dangerous as traditional combustion cars and that we are likely to NEVER see a lithium EV fire.
This counterclaim to me got 1,000s of likes maybe even 10,000s of likes. It really highlighted to me how dumb the world is and how much the human mind is biased towards ideology over anything to do with fact or logic.

https://www.youtube.com/watch?v=cTJh_bzI0QQ&t=347s
^Lithium battery inside burning on top of a bowl of water.

 

[flippy]

as long as burning EV's are still proper "news" they are still safer then the average car that runs on liquified dino's.

tesla and spacex also get a shafted on news cycles, just look at their recent "anaomaly" with crew dragon and why they havnt said anything about it. the exact same happend with starliner many weeks ago and they also havnt said anything and they had a brand new setup, not even a pod that actually went to space but nobody is pressing boewing about why their (brand new unused) setup exploded.

 

[Kajman]

How did a123 26650 burn? It was chemistry burn or just thing causing short circuit burned? Or heatshrink on cell because of heat? Very often cell does not have to have flamable chemistry, enough is what is doing short circuit or something close enough to catch temp.

 

[Hillhater]

Not easy choosing a “safe”. Option......
Recent house destroying Ebike battery fire in Sydney and a recall on defective Ezee batteries
https://www.smh.com.au/business/consumer-affairs/an-orange-flash-then-melanie-s-house-burnt-down-20190426-p51hj2.html?btis
Apparently Ezee are blaming the LG cells for a defect ?

 

[liveforphysics]

How did a123 26650 burn? It was chemistry burn or just thing causing short circuit burned? Or heatshrink on cell because of heat? Very often cell does not have to have flamable chemistry, enough is what is doing short circuit or something close enough to catch temp.

LiFePO4 still uses a graphite anode and additive stabilized carbonate ester electrolyte base. Most LIB failure mode initiates from the anode. They experience the anode breakdown failure mechanics almost identically to cells using different cathode materials, aside from that the lower voltage reduces electrolyte stress. When they are failing though, they need to get substantially hotter before the cathode material gives up it's Oxygen (which is part of why they can burn the electrolyte and separator plastics so vigorously like a little rocket motor). The thing is, if your battery was already at the temps where an NMC cathode would be liberating it's Oxygen (~170degC), then it's already experiencing a runaway anode failure. The big advantages in stability are lower voltage stresses making it a bit harder to upset the anode, but it's a misconception that they can't burn or experience runaway. The first gen A123 26650 cells had some pretty intense failure modes and got tamed down in the next generation (which sadly raised cell impedance).

 

[jonyjoe303]

The A123 that caught on fire was when I was dissembling a batterypack (96 cells), using pliers I was trying to remove the the nickle strip. The nickle strip tore the green sleeve on the cell and that shorted the cell which caused a hole in the can. The cells are capable of 70A discharge.

The fire coming from the hole was similar to a blowtorch, pouring water on it would cause the fire to die down but as soon as you removed the water it reflashed. It was a classic lithium fire. I no longer underestimate the hazards of lifepo4 which I think is about the same as 18650 li-ion. Thats why I always share my incident to let everyone know lifepo4 will catch on fire if improperly handled. If overcharged I'm sure it will catch on fire also, but I build my packs with multiple safeguards to prevent overcharging. After the fire I was more careful removing the nickel strip and was able to remove all cells without any more fires, thats close to 200 cells. In other words take your time when doing work around lithium cells. Never get complacent like I did, I always heard lifepo4 was safer so I was just rushing to take the pack apart.

I still use/build lithium battery packs. I think they are very safe as long as you don't mistreat them or underestimate them. The majority of fires are from overcharging or punching holes in them, both of which can be easily avoided.

 

[TheBeastie]

Don't know if these have been posted elsewhere but they are pretty spectacular lipo fires.
I was looking at HK's new lipo carry box and YouTube had a recommended video that tests HK's lipo holder box.

The ending part of this video is pretty funny bcos u think it flawless until he puts a bigger lipo in the box that destroys it.

[youtube]WR-Rw0PLgpA[/youtube]

[youtube]CnNId0mDnBo[/youtube]


Seems to me the most effective thing you can do against lipo fires is deny the battery oxygen.
You can buy large fibreglass fire blankets at your local hardware store for very little, wrap your battery up in this as well as putting it in a steel box. https://www.bunnings.com.au/family-first-1-8m-extra-large-fire-blanket_p4210536

This drone fire video is amazing, even though its in the snow it continually burns until basically every part of the drone is turned to ash.
https://www.youtube.com/watch?v=uQkgr5NjTVo

 

[dogman dan]

That's a cool box, and even better test of it. Put that thing inside your oven, or at least on the stove top under the hood would be a good idea. My current battery, 12s 10,000 mha would require two of them to charge safe.

Pretty clear that the vent holes in my lipo containers, ammo boxes, are too small. I used to put them with the vents pointing to the back, in my fireplace. My fire was not RC lipo, but "safe" bms protected 18650's. They are NOT safe.

What I ended up with after my fire, was a no longer usable electric oven. Its outside now, away from the house, and I keep all my batteries in it. I charge in the open air, on the glass cooktop.

My batteries do freeze in the winter in there, but it could be heated.. When its that cold, I'm pedaling now, so I go slower and stay warmer. But on a nice winter day, I put the cells in the sun for an hour to thaw before I charge them, if actually still frozen.

 

[tomjasz]

Just finishing a new 20MM ammo can with lid gasket removed and two 3/4 rubber grommet lined holes into the box for wires. First the sharp edges shorted a BMS ordered rubber grommets to sort that issue.

Next a double walled steel fire cabinet. Waited till Zorro had a 25% off sale and free shipping. Score a new cabinet for less than used on Craigslist. Waited anxiously for months before finding a livable price.

 

[obcd]

I am a newbie, but just wanted to put in my 5 cents open for discussion.

I disassembled a gazelle innergy battery for it's BMS board, as I had a battery with good cells and a bad BMS.

The first thing I notice on it is that the cells are separated from each other with some plastic holders.
This seems to be a way to prevent heat transfer from one cell to another.
Even when the plastic would melt, the batteries would still be held by the nickel strips holding them together.
The second thing I noticed is a temperature sensor directly connected to some cells of the pack.
Makes me wonder if an overheating cell could be detected before it goes into thermal runaway. (Or nuclear if you want to call it like like that.)
Most aftermarket chinese BMS boards don't seem to have such a temperature sensor and only check cell voltage and current.
This makes we wonder if most accidents happen during charging?
Obviously, a poorly build pack could get a short circuit at any moment.
That's another scary thing to think about. If you have a 4p or 5p pack, what happens if one of those cells becomes bad. If it drops voltage, the other parallel cells will release their energy into it and bad things can happen. Maybe the nickel strips connecting them should be carefully chosen so that they act as a fuse in case of overcurrent?
Obvious, leaving some space between the cells decreases the pack density.
I sure decided to keep the things with respect after what happened to Dan's battery.
Maybe 10 will just puff and be fine when you mistreat and/or short them, but the eleventh might burst into flames.
I also read some cells have a buildin security that disconnects the cell if things go wrong, and others don't have such. Some 18650 cells even seem to have a small electronic circuit buildin like a 1 cell BMS.

So do you think separating the cell a little from each other is a good idea?
Can we see the temperature measurement as an additional safety against thermal runaway?

 

[e-beach]

...........
So do you think separating the cell a little from each other is a good idea?

Cell separation for heat dissipation is a good idea. It also depends on other things like, how hard you drain (drive) your cells, ventilation, ambient air temperature, cell age, and I am sure there are more reasons cells get hot. The main point is to keep the cells from getting hot because that causes a lot of problems with lithium cells.

Can we see the temperature measurement as an additional safety against thermal runaway?

Yes, sure, it your battery pack is set up for that kind of monitoring. The question is, will you be monitoring your cells 24/7/365?
While you are riding you might keep an eye on the cell temperature, sometimes, but how about when you charge? Do you really want to watch your battery all day long? The point being is that, yes, monitoring cell temperature is a good thing, but it has it's limits as to how much time we have to spend looking after our batteries.