Any reason why they require low SOC?They have started to ship overseas with a lower SOC than before (Off-shore rules for lithium battery
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Any reason why they require low SOC?They have started to ship overseas with a lower SOC than before (Off-shore rules for lithium battery
31% sounds like a pretty close average SoC when the car is sitting in the garage. Coincidentally that is the SoC right now.The average SOC model is for daily but shows 31%, could this be about right har to judge from the description? (but it doesn't not matter much for the numbers)
The average ambient cas 12.2C for York so I took that number -> average cell temp about 20C. Could possibly be slightly lower.
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As I had a M3P 2021 with the same range/battery, I know is started (should have) at 315 miles/507km.
Should be around 309 miles/ 497,5km range today.
So then the capacity calculation, 78.96 kWh (lets call that 79 kWh) hit about right…31% sounds like a pretty close average SoC when the car is sitting in the garage. Coincidentally that is the SoC right now.
I just checked SMT and it is reporting 79.3 kWh and 310 miles range of the original rated 315.
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I really need to drive more.
Yes!Any reason why they require low SOC?
Have to add:I’m trying to keep the lowest energy possible overnight. It also gives me peace of mind that it has less chance of thermal runaway.
There is zero empirical evidence or theoretical mechanism to support this assumption. It's a complete myth that unlike the "avoid 100%" has literally nothing to support it.I was under the assumption that leaving the battery at a low SOC like 20% is bad for it.
I'd say it was dead-on, considering the SMT value can and does fluctuate by about 0.5 kWh in either direction.So then the capacity calculation, 78.96 kWh (lets call that 79 kWh) hit about right…
As already stated, its a myth.I was under the assumption that leaving the battery at a low SOC like 20% is bad for it.
As already stated, its a myth.
Here’s the real world:
Researchers have tested what happens if you leave the battery for months at different SOC.
(There are literally hundreds of research reports supporting this, so it can be thrusted as a fact.)
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I think a lot of people make the wrong assumptions about SOC when it comes to when a car is not in use. Yes it is not advisable to keep the Tesla at a really low SOC for an extended period of time like if you were to go on a vacation in case it goes to zero. But if you are just leaving it uncharged for like 2 days if you are not using the car is not going to damage the battery. But if you ever drain it to zero a few times it is not going to damage the pack permanently. Its just best not to make it a habit.I was under the assumption that leaving the battery at a low SOC like 20% is bad for it.
The car limits the power at low SOC so, no not a problem.Is there any negative side effects of the battery being heavily discharged at a low SoC (like a full throttle burst at 20%)?
Can you cite any technical support or rationale for this statement?Yes it is bad to keep the Tesla at a low SOC for an extended period of time like if you were to go on a vacation.
Lithium batteries are happy at low SOC. Even down to 0% real SOC which is well below 0% on the screen.I think a lot of people make the wrong assumptions about SOC when it comes to when a car is not in use. Yes it is bad to keep the Tesla at a low SOC for an extended period of time like if you were to go on a vacation. But if you are just leaving it uncharged for like 2 days if you are not using the car is not going to damage the battery.
No, he cannot.Can you cite any technical support or rationale for this statement?
Only when the pack has been punctured or deformed in an accident. I'm not aware of any cases where the pack itself underwent thermal runaway from being parked undamaged.
During the Bolt recall (used as a sanity check example, given Bolts did undergo thermal runaway), GM/LG recommended avoiding both high AND low SOCs, but they never explained the reason for either limits.
GM And LG Are Working Around The Clock On Bolt EV Battery Recall
I didn't review all the cases of the Bolt fires, but it's not hard to find with a quick google that they occurred even with cars parked with low SOCs (this one was only at 34 miles indicated range, or about 14%).
That is a very small subset of cases and even in that table many are unknown. I think the reason most are at 100% or close is because most people charge it to that percentage, so when it's done charging it will set there and that is the most prevalent SOC most of the time. It's not necessarily that it has to do with 100% specifically (like for example all if all of those people let the battery sit at 50% that the fire would be avoided).However, most publicly known Bolt fires where the state of charge was publicly known occurred at close to 100% state of charge. History of deep discharging was also implicated in increasing for risk in defective batteries.
Regarding Tesla battery fires, there do appear to be a few that do not seem to be crash or damage related. But the rate is very low.
When GM initially announced the first fire recall, it advised customers not to charge to 100% and offered an interim software that limited charging to 94%, since GM believed that being at 100% increased the risk of fire. Through various updates to the recalls, GM seems to consistently believe that 100% state-of-charge had the highest risk of catching fire, but also later noted that a history of deep discharging also increased the risk.That is a very small subset of cases and even in that table many are unknown. I think the reason most are at 100% or close is because most people charge it to that percentage, so when it's done charging it will set there and that is the most prevalent SOC most of the time. It's not necessarily that it has to do with 100% specifically (like for example all if all of those people let the battery sit at 50% that the fire would be avoided).