diy solar

diy solar

Tesla Battery charged to 28 volts, popping and shorted out

snoobler said:
No. Tesla batteries are typically a crapton of 18650 or 2170 cylindrical LiPo cells.

You say battery voltage was 28? Then battery voltage was 5.3V? Then battery is 21V?

WTF?

You have an incredible shit storm you need to deal with. I would disconnect that battery completely from everything and measure all the parallel cell groups and record their voltages (7 voltages). Visually inspect it for signs of blown fuses (the tiny little wires on each cell) if they're visible.

Take some pictures and post.
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Let me clarify. When the popping started, I went into the room where the system is housed. I heard a couple of loud popping sounds. I noticed the voltage on the charger controller was 28 volts. I shut off the battery cutoff switch and noticed the group of cells near the negative terminal were quite warm to the touch. At that time I checked the battery voltage and it was 5.3 volts. I was an electronics technician In the navy and this made no sense. I noticed the battery protector was flashing an error code of E1 (short). I assumed one of the cells was shorted. I went outside and disconnected the solar panels so the charge controller would shut down. Thats when I contacted you guys. I have since removed the entire battery from the room and its outside on a chair. I just checked the battery voltage now and its 21 volts and has been steady at 21 now for a while. Does that clear up any confusion? I dont believe the battery protector is the same thing as a battery management system (BMS). Any advice Now? Lol
 
Most Tesla Model S and X models have 6 cell bricks in parallel. (As @snoobler mentioned)
Nominal. 22.8 = 3.8 per cell.
Maximum 24.2 = 4.2 per cell
It has definitely been overcharged and stayed there for a while.
 
I was mistaken. 6S. That explains the issue. Cells were overcharged. Are they ruined? maybe (probably). Lucky there was no fire? DEFINITELY
 
MikeinElease said:
Let me clarify. When the popping started, I went into the room where the system is housed. I heard a couple of loud popping sounds. I noticed the voltage on the charger controller was 28 volts. I shut off the battery cutoff switch and noticed the group of cells near the negative terminal were quite warm to the touch. At that time I checked the battery voltage and it was 5.3 volts. I was an electronics technician In the navy and this made no sense. I noticed the battery protector was flashing an error code of E1 (short). I assumed one of the cells was shorted. I went outside and disconnected the solar panels so the charge controller would shut down. Thats when I contacted you guys. I have since removed the entire battery from the room and its outside on a chair. I just checked the battery voltage now and its 21 volts and has been steady at 21 now for a while. Does that clear up any confusion? I dont believe the battery protector is the same thing as a battery management system (BMS). Any advice Now? Lol
Click to expand...
Correct a victron battery protect is not the same as a BMS.
Unless you are Jehu Garcia you should not run a lithium battery without a BMS.
 
I
smoothJoey said:
You are not sup


The in-rush to prime the inverter's capacitors beats the snot out of the battery protect.
It should not be used in the high current path.
Does your inverter support remote switching per chance?
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I am not sure about remote switching. So I am assuming I need to research and purchase a BMS for the Tesla battery. I’m posting a pic of the battery. Thank you Joey!!!
 
smoothJoey said:
Correct a victron battery protect is not the same as a BMS.
Unless you are Jehu Garcia you should not run a lithium battery without a BMS.
Click to expand...
Any recommendations for a BMS. Please be kind here. I bought this entire system from a guy that had it in his RV. I’m still learning about this solar stuff. It’s all new to me.
 
MikeinElease said:
So I am assuming I need to research and purchase a BMS for the Tesla battery. I’m posting a pic of the battery. Thank you Joey!!!
Click to expand...

You absolutely need a BMS for "vent with fire" batteries.
I'm sorry to say but I think your battery is toast.
If it is, be happy nothing really horrible happened and get your self a lifepo4 setup.
 
28 volts is 4.7 per cell. Can you tell if the fuses are intact? Those are the little wires that connect each cell to the buss. There should be six distinct busses but maybe only three on each side.
 
Ampster said:
28 volts is 4.7 per cell. Can you tell if the fuses are intact? Those are the little wires that connect each cell to the buss. There should be six distinct busses but maybe only three on each side.
Click to expand...
All the little fuse wires coming off the top of the cells are in tact. No smells to note.
 
Ampster said:
I see three busses. Can't see detail enough to see if any fuse wires parted. You can see the BMS wires and you can check them or each brick to see how balanced it might be relative to the others. Not conclusive but another data point to assess the remaining health.
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I checked closely, all the wires are in tact. what can I do to determine if the battery is safe to reinstall and run it with just 400 watts of solar to see if it still works? I just checked the batter voltage again and it is 20.7 volts.
 
MikeinElease said:
I checked closely, all the wires are in tact. what can I do to determine if the battery is safe to reinstall and run it with just 400 watts of solar to see if it still works? I just checked the batter voltage again and it is 20.7 volts.
Click to expand...

Can you check the voltage of each string and report back?
 
smoothJoey said:
Honestly I would not put a pack that had been overcharged in any building that I wasn't prepared to toast marshmallows over.
Those cells are not forgiving.
Click to expand...
Thank you Joey. I may keep it outside and run wires to the battery while it is outdoors, just to see if it is still functioning. thats what I get for changing the setting. Lesson learned.
 
"Overcharging Lithium-ion
Lithium-ion operates safely within the designated operating voltages; however, the battery becomes unstable if inadvertently charged to a higher than specified voltage. Prolonged charging above 4.30V on a Li-ion designed for 4.20V/cell will plate metallic lithium on the anode. The cathode material becomes an oxidizing agent, loses stability and produces carbon dioxide (CO2). The cell pressure rises and if the charge is allowed to continue, the current interrupt device (CID) responsible for cell safety disconnects at 1,000–1,380kPa (145–200psi). Should the pressure rise further, the safety membrane on some Li-ion bursts open at about 3,450kPa (500psi) and the cell might eventually vent with flame. (See BU-304b: Making Lithium-ion Safe.)

Venting with flame is connected with elevated temperature. A fully charged battery has a lower thermal runaway temperature and will vent sooner than one that is partially charged. All lithium-based batteries are safer at a lower charge, and this is why authorities will mandate air shipment of Li-ion at 30 percent state-of-charge rather than at full charge. (See BU-704a: Shipping Lithium-based Batteries by Air.).

The threshold for Li-cobalt at full charge is 130–150ºC (266–302ºF); nickel-manganese-cobalt (NMC) is 170–180ºC (338–356ºF) and Li-manganese is about 250ºC (482ºF). Li-phosphate enjoys similar and better temperature stabilities than manganese. (See also BU-304a: Safety Concerns with Li-ion and BU-304b: Making Lithium-ion Safe.)" -- https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries
 
MikeinElease said:
Thank you Joey. I may keep it outside and run wires to the battery while it is outdoors, just to see if it is still functioning. thats what I get for changing the setting. Lesson learned.
Click to expand...

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