Where there is smoke, there is Fire

[Russel]

I’m sitting at my computer last night when I smell a strong odor, something like nail polish remover. I call for my wife to see if she is working on something that might cause this. She says no, but that she also notices a strong odor near my desk.

Not far from my desk is my latest solar project. Could that be the problem? I open my plastic battery box and see smoke! I’m stunned. My LiFePO4 batteries, charged at 0.1C, have been top balanced a few days ago, but have not yet been connected to anything. How can this happen?

As fast as possible, I move the battery box out to the patio as the house is filling up with smoke. I expect flames to erupt at any moment, but no flames appeared, just lots and lots of smoke.

Once the battery box was on the patio, I removed the batteries from the box and put the now heavily smoking battery in the middle of my yard, just in case. I could see some fluid in the bottom of the battery box.

Questions:

What the hell just happened?

How is it that I and only I seem to have these types of issues and I only have a few batteries? (I would think that Will, Lithium Solar and others, who test batteries and have lots of different ones laying around, would have also experienced something similar at least once.)

What should I do next? (I am now honestly afraid of this technology. What if I had not caught it early? What if I was sleeping or out for the day and this happened? What if I was out and my wife was home when the smoke started? What if, instead of a battery box with wheels, they were mounted in a rack or some other fixed location, like in my basement, etc. or worse, an RV, etc. I would rather lose money on my batteries than lose my house or my life.)

The batteries in question are sold by Eco-Worthy and are the 150 Ah version with a blue label. I cannot recommend this product to anyone. With one battery initially DOA and this issue, I don’t believe this company has poor quality control. I believe that they have NO quality control.

Now I have a hazmat issue to fix as well.

 

[HRTKD]

Perhaps the top balance was too high? Did you have a way to measure the voltage of each cell?

 

[Mattb4]

Although ECO-Worthy slaps their label on it I would bet the battery is simply a generic Chinese assembled unit. From China to you it is hard to say what it might have experienced during shipping. The big question is does Eco-Worthy stand by any Guarantee they claim for the battery?

I can certainly understand how your experience would make you leery though. Just have to keep in mind if it is a rare situation or a more common thing. That is where those that have used the battery type for years can give their experience on. It is like pointing to Teslas that caught on fire after being submerged in saltwater by the Hurricane that hit Florida. I would not use that example to state Teslas batteries are no good.

 

[Wjm1964]

Very unsettling experience. 1st call should be to Eco-Worthy as I'd imagine they would want to know what happened too. Glad no one was hurt.

 

[Russel]

If this CAN happen to any battery, does this make a case for including a smoke detector/heat sensor in your battery box? What do you do if it goes off?

Perhaps the top balance was too high? Did you have a way to measure the voltage of each cell?

The batteries are sealed. No way to measure individual cells. I have four of these batteries, counting this one, and other batteries as well. Never a problem. My charger puts out a max of 10A @ 24 (nominal) volts. The batteries state a max charge rate of 100 A. I don't see a problem there. Once the charrger is finished, it shuts off.

I just used an infrared thermomoter to measure the case temperature on the failed battery. It's over 80F and has a new swell spot. I'm not sure it is done cooking so I could not ship it anywhere until it stabilizes. Looks like another cell is is the process of failing.

This battery was purchased 5 months ago, and was not yet put into service. I'll let the forum know what the vendor has to say about this.

 

[MrNatural22]

Contact ECO-Worthy ASAP and use the warranty. Hopefully your pics and documentation will trigger an easy refund or replacement. It will be a good test of how their customer service responds to consumers.

 

[Bluedog225]

Sorry for your troubles. I’m curious how much this battery cost?

Trying to better understand the cost/quality/safety tradeoffs of various batteries. With Battle Born 100 amp hour at the top being about $800 and seemingly issue free for the great majority of customers for 10 years.

 

[wattmatters]

The batteries are sealed. No way to measure individual cells.

My LiFePO4 batteries, charged at 0.1C, have been top balanced a few days ago

Curious as to how you do a top balance if you can't measure individual cells?

 

[mikefitz]

Why are you charging a 12v battery with a 24 volt charger?
What is this 'top balance ' you are attempting?
Was the battery attached to a charger or anything else when it failed?
What charger are you using?

 

[DJSmiley]

How can you topbalance a sealed cell?

And you state you're using a 24V charger, so I assume 2 batteries in series? Were both batteries at equal SOC before connecting, and does the BMS allow serie connections at all?

And as said by others, Ecoworthy is just a cheap chinese one which does put their own stickers. They might use proper BMSses, but it might be just a random cheap BMS as well. Did you do a teardown and/or check which BMS is used in these specific batteries before connecting in series?

To me, it looks like 2 batteries with different SOC's are used in series, thus eventually overcharging 1 battery, and/or a BMS which is not rated for series connection or failed to do its job.

But anyway: Most important is you're still fine, and apart from shittig your pants, nothing worse has happened.

 

[Supervstech]

If this CAN happen to any battery, does this make a case for including a smoke detector/heat sensor in your battery box? What do you do if it goes off?

The batteries are sealed. No way to measure individual cells. I have four of these batteries, counting this one, and other batteries as well. Never a problem. My charger puts out a max of 10A @ 24 (nominal) volts. The batteries state a max charge rate of 100 A. I don't see a problem there. Once the charrger is finished, it shuts off.

I just used an infrared thermomoter to measure the case temperature on the failed battery. It's over 80F and has a new swell spot. I'm not sure it is done cooking so I could not ship it anywhere until it stabilizes. Looks like another cell is is the process of failing.

This battery was purchased 5 months ago, and was not yet put into service. I'll let the forum know what the vendor has to say about this.

I strongly suggest you purchase a 12V charger and use it with the remaining batteries...
Don't use the term "top balance" as you are using it wrong.
My guess is their bms failed, and your charger just kept trying to get 24V ...

 

[Russel]

Sorry for your troubles. I’m curious how much this battery cost?

Trying to better understand the cost/quality/safety tradeoffs of various batteries. With Battle Born 100 amp hour at the top being about $800 and seemingly issue free for the great majority of customers for 10 years.

This battery is about $500 on Amazon. I was attracted to it as it was rated 150Ah vs 100Ah of other batteries in that price range.

 

[Russel]

I strongly suggest you purchase a 12V charger and use it with the remaining batteries...
Don't use the term "top balance" as you are using it wrong.
My guess is their bms failed, and your charger just kept trying to get 24V ...

At the time of failure, this 5 month old battery was in series with a similar battery to provide 24v, but it was not connected to anything. Other than the initial charge when I first got it, and then again about a week prior to the failure, nothing was ever connected to this battery. It was just sitting there idle when it failed.

What if this was installed on a boat or in an RV?

 

[Russel]

Curious as to how you do a top balance if you can't measure individual cells?

I connected this 12v battery in parallel with another 12v battery and charged them both @ 12 volts. If there is another name for doing this, please let me know what it is?

 

[Russel]

Why are you charging a 12v battery with a 24 volt charger?
What is this 'top balance ' you are attempting?
Was the battery attached to a charger or anything else when it failed?
What charger are you using?

The charge is auto 12v and 24v. You can see what mode the charger is in and it was correct.

 

[Russel]

How can you topbalance a sealed cell?

And you state you're using a 24V charger, so I assume 2 batteries in series? Were both batteries at equal SOC before connecting, and does the BMS allow serie connections at all?

And as said by others, Ecoworthy is just a cheap chinese one which does put their own stickers. They might use proper BMSses, but it might be just a random cheap BMS as well. Did you do a teardown and/or check which BMS is used in these specific batteries before connecting in series?

To me, it looks like 2 batteries with different SOC's are used in series, thus eventually overcharging 1 battery, and/or a BMS which is not rated for series connection or failed to do its job.

But anyway: Most important is you're still fine, and apart from shittig your pants, nothing worse has happened.

The 12v batteries are sealed, so no way to inspect the BMS. And yes, the batteries were of equal voltage before they were connected.

 

[wattmatters]

I connected this 12v battery in parallel with another 12v battery and charged them both @ 12 volts. If there is another name for doing this, please let me know what it is?

Top balancing means ensuring the individual cells inside the battery (there are usually 4 of them in series) are at equal voltage when the battery is at or very close to a 100% state of charge.

Putting two batteries in parallel will equalise the voltage between them. That's about it. But it won't top balance anything.

At the time of failure, this 5 month old battery was in series with a similar battery to provide 24v, but it was not connected to anything. Other than the initial charge when I first got it, and then again about a week prior to the failure, nothing was ever connected to this battery. It was just sitting there idle when it failed.

Are the batteries rated to be placed in series? Many are not.
The specifications need to explicitly state they are rated to be connected in series.

The 12v batteries are sealed, so no way to inspect the BMS.

Some battery BMSs provide a bluetooth connection and mobile device app.

 

[Supervstech]

I connected this 12v battery in parallel with another 12v battery and charged them both @ 12 volts. If there is another name for doing this, please let me know what it is?

Hmmm. Charger set to 12V, but the failed battery wasn’t being charged at the time.
Only connected to another battery in series… and the set wasn’t connected to anything else?

I would love to know what failed.

 

[eemarty]

At the time of failure, this 5 month old battery was in series with a similar battery to provide 24v, but it was not connected to anything.

Could you explain exactly what was connected to the two terminals of the battery? Do you mean that you had two batteries with the positive of one battery connected to negative of the other and there were no other connections to either of the batteries?

 

[Russel]

Could you explain exactly what was connected to the two terminals of the battery? Do you mean that you had two batteries with the positive of one battery connected to negative of the other and there were no other connections to either of the batteries?

Two batteries wired in series, connected to two other batteries wired in series, connected to NOTHING. The wiring was done compliant with Victron's recommendation.