I was in an accident on Feb 21. My car sat in the tow yard for about 4 weeks with both batteries completely dead. Lots of very cold nights with 0% makes me think my battery could be damaged. It's at the repair shop now after a month and still has not been charged. My insurance company has been a nightmare to deal with so far.
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Is my battery toast?
- Thread starter johnny_snow
- Start date
jdcollins5
Member
davewill
Active Member
I don't think that having it sit a "0%" is going to ruin it, not in a month's time, but it isn't good for the long term health of the battery and should be remedied. However, I'm wondering why it would be at 0%. If the 12v battery is dead, then the HV battery is disconnected from everything and it wouldn't discharge significantly after that. Besides, most things that can drain the car (Sentry mode, cabin overheat protection, etc...) while it's sitting will shut down at 20%.
ucmndd
Well-Known Member
Batteries don’t mind cold storage at all. More likely than not everything is completely fine.
AlanSubie4Life
Efficiency Obsessed Member
Batteries seem to be completely indestructible (except when they fail of course but not relevant here) so wouldn’t worry about it for a while.
The HV battery disconnects from the car systems when the SOC is low enough, but still high enough to be safe.
After disconnection there probably is no (or virtually no) consumers attached so there will be only the self discharge using up the energy. Self discharge is low on lithium ions and is very very low at low SOC.
Lithium ions do not “loose” a lot of percent SOC at low temperature in the way the car show it to us. Lithium ion batteries also keep about the same voltage at low temperature.
So even at low SOC and low temperature the battery is fine.
There is a limit though, if the battery goes way past the minimum voltage of 2.5V/cell, then it could be damaged from overdischarging. In most cases lithium ion batteries is not that sensitive to just a little overdischarge.
Actually low SOC (but not too low) and low temperature is the best way to preserve the battery so it was probably good for the battery.
If the car estimates about the same range after being used all should be good.
After disconnection there probably is no (or virtually no) consumers attached so there will be only the self discharge using up the energy. Self discharge is low on lithium ions and is very very low at low SOC.
Lithium ions do not “loose” a lot of percent SOC at low temperature in the way the car show it to us. Lithium ion batteries also keep about the same voltage at low temperature.
So even at low SOC and low temperature the battery is fine.
There is a limit though, if the battery goes way past the minimum voltage of 2.5V/cell, then it could be damaged from overdischarging. In most cases lithium ion batteries is not that sensitive to just a little overdischarge.
Actually low SOC (but not too low) and low temperature is the best way to preserve the battery so it was probably good for the battery.
If the car estimates about the same range after being used all should be good.
Wow, I hope no one was in the passenger seat! How do you know both batteries are at 0%? Or are you just assuming? If the 12V battery is dead then you can't log into the car to check on it. To bring the car back alive it might need a new 12V battery. But the HV battery may still be sitting close to the charge it had after the accident.
When the accident occurred I was about 15 miles from a supercharger at about 25%. I turned on the hazard lights and left. The guy at the tow yard didn't know how to shut them off so they stayed on until both batteries were completely dead. Hopefully the repair place can look at the car this week as it has been over 6 weeks now.
Was on a 2 lane road with a slow vehicle driving in the fast lane. I tried to pass on the right lane and as I was beside them they switched lanes without looking or signalling and I went into the shoulder (so I didn't hit them) and lost control. Sucks because insurance says if I didn't make contact and they did not stop and admit fault it is considered my fault. Dashcam doesn't show their license plate because it was covered in snow.
But the HV batt is not completely dead when it shuts down. It shut down to protect itself so there is a margin to getting too low voltage in the cells.
Probably not very much so there is no complete guarantee that it hasnt gotten damaged.
Lithium ion cells can handle some overdischarge without getting damaged so it might not be any danger even if its below 2.5V/ cell.
Probably not very much so there is no complete guarantee that it hasnt gotten damaged.
Lithium ion cells can handle some overdischarge without getting damaged so it might not be any danger even if its below 2.5V/ cell.
The legal reasoning behind that is that a driver is required to maintain control of their vehicle at all times. So if you swerved, even to avoid an accident, but lose control in the process, you are placed at fault. While the last clear chance doctrine says you should try to avoid an accident, you shouldn't lose control trying to do so. I don't know of any insurance company that didn't view it this way in general (speaking as a former adjuster).
I will say that with so many more people having dashcams now, I wouldn't be surprised if they attempted do go after these vehicles of they can be identified, but their carriers are likely to defend themselves based on the reasoning above. Video evidence was quite rare when I was in the industry so I'm not sure how it's evolved since then. Legal theory really shouldn't change as a result, but video evidence could be compelling in front of a jury....
They ended up charging my battery after sitting at 0% for 7 weeks and it charged up to exactly what it usually did before all this happened. 160,000km and showed 445km range at 100%.
Nice!
That was about what we expected. Keep us posted if you get any issues in the future (I bet you wont), but anyway it would be good to know that we get that info, and as long as we have not = we can assume all is good.
Any update on this @johnny_snow ?
I know what I think from research, but to help others understand that low SOC is not a bad thing…
Unless you have al LFP battery, you now have the problem of having your battery sitting at 100% which is definitely bad for it. Find a way to discharge it to 50% as soon as possible. It degrades pretty badly if left at 100%. Even LFP batteries do not like to sit at 100% for a long time.
There is not a big difference between LFP and other like NCA and NMC for the ”sitting at 100%”.
The sitting at 100% is not at all that bad as the forum rumor says. Not even close actually.
In general, there is most often no real reason to have the car standing at 100% but if it by some reason is, theres no reason to panic.
This thread is old, and @johnny_snow got it back > 6 months back or so, so I’m positive it is not still at 100%
But it's still better to have it sitting at 50% than 100% right? I know there is no concern having the car sit at a lower state of charge but I had thought you said a while back that higher states of charge reduces battery health faster.
It increases calendar aging vs, say, 50% fairly substantially, does it not? Isn't that the whole thing?There is not a big difference between LFP and other like NCA and NMC for the ”sitting at 100%”.
The sitting at 100% is not at all that bad as the forum rumor says. Not even close actually.
In general, there is most often no real reason to have the car standing at 100% but if it by some reason is, theres no reason to panic.
This thread is old, and @johnny_snow got it back > 6 months back or so, so I’m positive it is not still at 100%
AlanSubie4Life
Efficiency Obsessed Member
He just means for a day or so (or whatever) at 100%. As long as you don’t store it there it does not matter much. Yeah it increases calendar aging for as long as it is at that charge. But no reason to panic. Not a big deal. Much more important to just keep the average charge level low if you want to reduce such aging.