Tesla Battery charged to 28 volts, popping and shorted out

[John Frum]

The lesson is a never run a lithium ion battery without a BMS.

The other lesson is lifepo4 is certainly safer than "explody" lithium chemistries.

 

[snoobler]

This picture shows the 6 cell zones of the module:



measure voltage from these six zones to the same region on the opposite side to get the 6 voltages.

 

[MikeinElease]

Thanks for the info. All the zones were 4.3 to 4.4 except for the zone closest to the negative terminal. That is the area that got hot. It only reads.97 volts.

 

[snoobler]

You just confirmed the module is destroyed. Sorry. Very fortunate you didn't experience a fire.

 

[MikeinElease]

Module meaning the entire battery? Damn. That was a costly experiment, changing the settings.

 

[snoobler]

With the 5 zones at over-volt of 4.3-4.4, they are likely damaged. With the 6th zone at 0.97V, definitely damaged. Could this be salvaged in some way? Possibly, but it would take some knowledge and detailed testing.

 

[Ampster]

Unfortunately I dont know how to test the voltage on each string.

I see you figured it out.

With the 5 zones at over-volt of 4.3-4.4, they are likely damaged. With the 6th zone at 0.97V, definitely damaged. Could this be salvaged in some way? Possibly, but it would take some knowledge and detailed testing.

I agree they are probably all damaged. If he has the skills he can try to revive it but it is not for the faint of heart. First he needs to pull down those overvolt modules with a headlight or big resistor. Then he needs to try to slowly see if he can charge the remaining brick. Then attach a BMS and do a capacity test, watching the cell voltages as they reach the knee at the top of charge cycle and bottom during the discharge cycle. I would do the first capacity test with very conservative settings watching for a runner. Then if everything remains balanced he could be more aggressive to see if he has any useful capacity left and no cells bricks that much weaker that the others.

 

[MikeinElease]

You just confirmed the module is destroyed. Sorry. Very fortunate you didn't experience a fire.

Thank you guys. I really appreciate all your advice and help. Very sad now that my entire system is down.

 

[gnubie]

Sad that your system is down, but on the bright side things didn't get out of control and burn your house down.

 

[MikeinElease]

Hopefully one last question. If I get a battle Born battery, I should switch the charge controller to the po4 setting correct? And will I need a BMS for just one or two batteries?

 

[John Frum]

Hopefully one last question. If I get a battle Born battery, I should switch the charge controller to the po4 setting correct? And will I need a BMS for just one or two batteries?

Please enumerate the charge profile names so we can better advise you.

 

[snoobler]

I linked the manual earlier:

https://www.victronenergy.com/upload/documents/Manual-SmartSolar-charge-controller-MPPT-150-70-to-150-100--250-70-to-250-100-VE.Can-EN-NL-FR-DE-ES-SE-IT.pdf

28.4V charge, 27.0V Float

Looks fine according to:

The Basics of Charging LiFePO4 Batteries

Click here to read all about charging your LiFePO4 batteries and the recommended charging parameters from Battle Born Batteries!

battlebornbatteries.com

(28.8V Absorp, less than 27.2V float)

If he has the bluetooth unit and can use Victron Connect to program it, he can hit their numbers exactly.

 

[MikeinElease]

Thank you. Lots to consider. May need to get a solar pro to help me.

 

[snoobler]

The Battleborns are going to be very spendy and you'll have about 1/2 the capacity you did prior. Another Telsa module with a suitable BMS is probably still more cost effective per kWh.

I am partial to LiPo as I have about 39kWh of individual 24Ah LiPo cells from Ford Fursion Energi packs. My build is going to happen one day...

 

[John Frum]

The Battleborns are going to be very spendy and you'll have about 1/2 the capacity you did prior. Another Telsa module with a suitable BMS is probably still more cost effective per kWh.

I am partial to LiPo as I have about 39kWh of individual 24Ah LiPo cells from Ford Fursion Energi packs. My build is going to happen one day...

@MikeinElease please don't do this.
Alternatively you could get some of the lifepo4 prismatic cells and a bms more capacity and less scratch than the Battleborn.
Search the forum for Xuba to see the current popular choice.

 

[Ampster]

I am partial to LiPo as I have about 39kWh of individual 24Ah LiPo cells from Ford Fursion Energi packs. My build is going to happen one day

I would be surprised if they were trully Lipo, aka LiPoly or Lipol. I suspect they are some form of NMC chemistry with Cobalt. They are manufactured by Panasonic.

 

[John Frum]

https://www.victronenergy.com/upload/documents/Manual-SmartSolar-charge-controller-MPPT-150-70-to-150-100--250-70-to-250-100-VE.Can-EN-NL-FR-DE-ES-SE-IT.pdf

Hmmm according to the doco none of the profiles were suitable for that tesla battery.
The lifepo4 profile was actually slightly better than the default.

 

[snoobler]

I would be surprised if they were trully Lipo, aka LiPoly or Lipol. I suspect they are some form of NMC chemistry with Cobalt. They are manufactured by Panasonic.

Correct. I'm lazy. I call everything not LFP, LiPo...

 

[gnubie]

Hopefully one last question. If I get a battle Born battery, I should switch the charge controller to the po4 setting correct? And will I need a BMS for just one or two batteries?

Victron's built in lifepo4 profile is good enough in terms of voltages for a lifepo4 battery but you should adjust the default absorption charging time to suit your setup. If you have a Victron shunt you can use the tail current method, if not you may find that 15 mins is sufficient to bring the battery up to 28.4V and let it do any cell balancing.

 

[John Frum]

Hopefully one last question. If I get a battle Born battery, I should switch the charge controller to the po4 setting correct? And will I need a BMS for just one or two batteries?

Battleborn batteries have a built in BMS.