My Project Lithium Battery Caught Fire

Sorry I didn't reply sooner... I got really sick last week... seems like a combination of covid and allergies, although I tested negative.

Please review the previous posts. One test (the one that yields 50%) was performed in a noble gas, hence there was no chemical reaction due to flame, unless that flame was oxidized by chemicals within the cell (unlikely for LiFePO4)).

I'm always down to read quality sources.

Yeah, A123 initially only sold to those that would allow A123 to review their designs. They didn't want some rando to tarnish their name by designing and selling dangerous products. Even the KillaCycle guy got a slap on the wrist after he crashed his A123-equipped bike into a parked truck. At the time A123 was the only game in town for high charge/discharge lithium, so you basically had to play by their rules. I'm still amazed they managed to go bankrupt.

Related: I still have an A123 cell on my long term tester that hasn't failed yet.

In general there are three broad categories:
-Overcharging (chemical breakdown)
-charging too fast (electrical resistance)
-failure to account for cell aging (NexPower packs lack any method to control this)

Interesting stance.
I would counter (again) that selling an LFP product without a BMS is a recipe for disaster.
I would counter that in at least five cases (that I know about), it "didn't work"... the pack experienced a thermal event.
I would also counter that the customer shouldn't expect their product is going to have a thermal event. Doesn't matter if that is fire, smoke, or just a thermite meltdown... the pack should have the requisite parts to prevent it from disassembling itself in a gooey form under the rear seats. No customer wants that, and well designed products have measures to prevent this from occurring.

I agree this happens, albeit infrequently.
Note that NiMH voltage dips slightly as each cell hits full, which the OEM computer can detect. This allows the OEM computer to determine when a cell is full. It's not perfect, but it's something. Note that this chemical property of NiMH cells is measurable even with multiple cells in series between BMS leads, whereas lithiums gradual (and then faster) cell rise is much harder to detect without per-cell BMS leads).

 

I like how you embraced the honda boy. :: wink ::

 

In each of these instances, cell voltage rise or drop below the stable voltage limits precedes temperature rise .... stop the charging or load when the voltage goes outside these ranges and the thermal run away never occurs, negating the need for thermal measurement per cell.
Once more than a single cell in series is involved in the voltage measurement, it becomes a bit trickier to stay within the stable voltage range for each cell in the series group, the more in the group, the closer to impossible voltage alone can avoid a thermal event in any cell within the group.

T1 Terry

 

Unfortunately for my wife and I, a day after we returned home to attend doctors appointments, both our house and motorhome burnt to the ground. From what I can tell, the power companies electrical meters in the power box or something within this metal box, started the fire. It burnt the corrugated iron garage it was attached to, the motorhome was parked between the garage on the house, so it caught fire and carried it over to the house.
We were at the doctors some 40kms away when the neighbour rang to tell us the whole lot was on fire, by the time we reached, there it was a matter of watching everything go up in flames .... we had what we were wearing and the Prius we were travelling and Coco the dog, and that was it. Our business workshop burnt down 15 mths ago, nearly to the day, between them, everything we had is now gone ..... had to go to a late night supermarket to buy jocks and socks and the next day, buy a computer because we both lost ours and all the back up hard drives .... we had stored one in the house and one in the motorhome for redundancy ...... the wife is ex IT, so has zero faith in the cloud keeping anything secure, very recent events have confirmed her doubts it seems ......

So, unfortunately, there will be no results from tests on the different Na ion cells (15Ah cylindrical and 200Ah prismatic) because they appear to have been destroyed in the fire as well ...... still can't get in the place until the forensic investigators for the house insurance and motor home insurance companies have been and recorded their findings ......

T1 Terry

 

As the title refers to a battery catching fire that would require some sort of intervention to stop the vehicle being engulfed in flames and destroyed, it clearly didn't happen, did it?
An actual fire would be a serious issue, a cell venting is more of an inconvenience issue, a serious one, but at no stage life threatening.
On those grounds, it falls back to "buyer beware" and in reality, the LFP is a far safer chemical formula than any that contain cobalt, that would have resulted in fire without a doubt under the same conditions.
I still dispute the hydrogen being part of an LFP electrolyte vapour release .... if you have ever witnessed a fire where hydrogen was in the gas mix, the heat and intensity of the rapid fire front is very close to an explosion and very little partly burnt vapours or gasses remain in the smoke cloud ..... not a "smoke cloud" but rather a fireball .....

T1 Terry

 

I'm very sorry for your loss, glad you and your wife and Coco are ok.

Something very similar happened to my parents years ago. The insurance company sent 'round a forensic electrical guy who hacksawed out the meter box and tossed it in the trunk of his car and drove off. My parents assumed for some time that they might eventually hear something from him about the cause, but he never seemed to make any report to anyone but the insurance company that sent and paid him.

The forensic guy happened to be the dad of someone I knew through contra dancing, but that didn't give me any extra leverage to learn what happened.

 

Interesting, we had the fire and police fire investigators visit the site when the last of the fire was being extinguished. They seemed to avoid looking at anything that might point to a govt body fault and rather attempted to twist the finding to point to the fire starting in the motorhome ..... even though it was obvious from the damage pattern, the prevailing wind direction and the fact the meter box was laying on the ground completely burnt out, just where the fire started.
It will be interesting to hear what the two different insurance company forensic people find, they will be desperate to blame someone other than their insurer for the fire. My guess, and only a guess on my part, the electrical people accept the blame and pay up, with the condition being a total non disclosure ...... the last thing they would want is an investigation or scare campaign to start and all power boxes requiring a safety audit ........ The power company recently installed new meters that both report to the electrical supplier to eliminate the need for a meter reader, and change the power charging to time of use rather than a flat rate ........

T1 Terry

 

Off Topic

T1 Terry, sorry to hear about the loss of your property. I’m a residential electrician and have been dealing with “smart” meter issues. I have had issues with AFCI/GFCI circuit breakers constantly tripping or failing, or costumers losing appliances to electrical damage. Surge protectors seem to solve some of the issues, but it seems to be more like a bandaid on a bigger issue. Costumers with older meters have not had any issues. Thankfully no electrical fires.

Sorry for my late post since mudder invited me here July06. My grandfather passed away and I was his executor of estate. That is a job on its own.

On Topic

I experienced a thermal event with my V2.5 battery pack back in April. My experience was similar to sworzeh’s so, to keep this short, I will point out the differences.

Differences

My car is a Lexus CT200h with +180,000 miles and is driven in the hill country of central Texas.
My V2.0 batteries were purchased 2023Aug.
My V2.5 battery upgrade was 2024Feb and it came with the signal soother.
I had a P0A80 pending code with the V2.5 pack, whether the signal soother was install or not. Drive cycles nor Techstream could not clear the code.
I did not notice any engine reving, start/stop, or car and battery “sync” issues.
My incident happened in 2024Apr, the temperature was around 75°F and I was driving 35mph on a divided 4 lane highway in afternoon traffic.

I found out about sworzeh’s post via a cross post on Reddit.

I used the word “issue(s)” six times.

 

Can you post a picture of the failed module(s)?

 

Here ya go.

 

3 cells in series with no voltage monitoring, a failure waiting to happen even if the 3 cell average high voltage and low voltage was monitored. Each cell monitored for a max of 3.8v and min of 2.5v, still outside the damage voltages but enough to allow for heavy charging or discharging, and that sort of thing can't happen .... even a dead short within any single cell will shut the battery down if a cell drops below 2.5v, the higher the cell capacity, the less likely the short will last more than milli seconds, the arc simply burns off the contact area ..... except when it comes to pouch cells, all bets are off when it comes to using pouch cells in parallel

The real problem is these pouch cells in parallel series have no method for transferring the heat out of the module. The centre parallel group got the hottest and would have caused multiple pouches to fail, they simply aren't designed to hold any pressure really.

So many major manufacturers are learning the errors of using pouch cells without cell voltage monitoring and heat monitoring and not using state of the art heat exchangers, a small start up doesn't stand a hope.

The Kia EV6GT 567hp unit runs the pouch cell 800v architecture, "a braver man than I Gunga din" if you start messing with one of them ......

T1 Terry

 

Factual Correction that nobody disagrees with:
NexPower's V1/V2/V3 products are actually 5 cells in series between voltage measurement taps.

Unfortunately, I cannot reply to your other points, as this forum's moderators have instructed me to not post further feedback that might upset NexPower's fanbase. I am staying in my lane, lest they ban me for reasons I disagree with. Information wants to be free.

 

My 2 cents...
Project lithium advertises the batteries as having "260 amps of peak power over the original NIMH pack's 100 amps".
Putting something with a lot more amperage than before, especially almost 3 times as much, is never a good idea. All of the high voltage wiring, inverter, motors, etc is designed for a certain amperage.

Also I'm pretty sure the safety plug has a 150A fuse, so this seems like a moot point.

 

Regardless of peak continuous amps capability, a power source only provides what the load requires. What can be changed is capacity and more capacity (storage) is generally desirable. What often happens with newer chemistries is the voltage stays higher even when significantly discharged. This causes the NiMH control logic to be “tricked” into using battery power longer. As a result the party trick of full ev in a hybrid is enhanced and in theory more capacity means more regen storage. All noble quests until it suddenly fails without warning with unpredictable consequences.

 

125, if I remember right. Gen 3 anyway. I don't know about later gens.

 

I suppose I should test this claim in the lab and then post my results on youtube.

Unfortunately, I cannot post that video here, as this forum's moderators have instructed me to not post further feedback that might upset NexPower's fanbase. I am staying in my lane, lest they ban me for reasons I disagree with. Information wants to be free.

 

The moderator seems more interested in hurt feelings than science, safety or reliability.

 

Well when you are a new member here and all you do is post attacks on a member that has been here since 2017 who has been helping this community with the Dr. Prius APP that we all know and use and trying to keep our cars on the road with new HV batteries, then it doesnt look good for that new member and any other new members who decide to attack out of the blue.

 

Odd that the mod would attempt to curb scientific discourse for so pedestrian a reason. It's certainly not what I would've expected from this forum.

 

Sometimes common sense isnt so common and it takes time for those whos logic is delayed to comprehend.

Clearly the moderator has logic and can see what is going on.