Not charging to 100%

[redrog]

The last couple of nights (Octopus Go) my M3 RWD LFP has stopped charging early at 97%. Never had this issue before. Is it the cold weather? It’s my first winter with it so not entirely sure what I should expect.

 

[MrBadger]

Probably the cooler weather. It will be the discrepancy between usable energy capacity and gross capacity. It will likely come back to 100% as things warm up, although by then the car has normally been driven so you don't notice the increase in %/miles.

 

[redrog]

OK I’ll see how it goes. Might be a calibration issue I suppose.

 

[Jason71]

OK I’ll see how it goes. Might be a calibration issue I suppose.

LFP or not I still would not recommend charging to 100% every night any way so its probably doing you a favour

 

[kelvin 660]

LFP here and never had a problem, always charges to 100% no matter what the temperature is...

 

[Big_D]

LFP or not I still would not recommend charging to 100% every night any way so its probably doing you a favour

Tesla actually recommends charging the LFP batteries to 100%. Not a problem.

 

[Jason71]

Tesla actually recommends charging the LFP batteries to 100%. Not a problem.

Aware of that. But there is a lot more to it. There is an entire thread on it if you are interested.

Should LFP batteries be charged to 100%?

LFP batteries can be left sitting at 100% without any problem, unlike NCA. They cannot long term. There is nothing magical about the LFP batteries Tesla use compared to all other LFP batteries. But in a practical sense it would be fine for a few hours or even days - the degradation would be...

teslamotorsclub.com

But the very short version is the LFP batteries voltage range is much less than that of Nickel batteries so the BMS struggles to stay calibrated. Charging regularly to 100% provides a reset for the BMS. This is why Tesla want you to do it
BUT
An LFP battery is still an Li battery and none of them benefit from being charged to 100%. None of them. So doing it regularly you are sacrificing battery life for BMS accuracy.
Personally I would do 100% once a week max and not hold there if it were me and I was bothered about long term degradation, irrespective of what Tesla say.

 

[bonklaus]

The last couple of nights (Octopus Go) my M3 RWD LFP has stopped charging early at 97%. Never had this issue before. Is it the cold weather? It’s my first winter with it so not entirely sure what I should expect.

Hi redrog, I noticed this too, however I put it down to the car preconditioning for the morning. I set it to 100% as we were due to travel to Essex from Devon, and I woke up to it being 96%. I'm also with Octopus Go and the charging schedule is set by the app that we download. So putting the two together, I reckon that the car may have charged to 100% (for example) up to 5:30am and then preconditioned for an 8am departure, thus using a small amount of energy. This is what happened to me, anyway. Hope this helps!

Bon

 

[redrog]

Preconditioning is off on mine so it’s not that. But it made 99% today so maybe it’s sorting itself out.

 

[Llama.]

I’ve never had this in my M3 LR. But I have charged to 100% only to see it slip to 98% due to preconditioning

 

[spdpsba]

Preconditioning is off on mine so it’s not that. But it made 99% today so maybe it’s sorting itself out.

I had the same problem usually charge to 100% (weekly NOT everyday) but when I charged on the 18th surprised to see it was stuck at 96%. I checked twice as this has never happened. I was aware of the previous night battery state - around 78%, so normally the 1230-430 time period tops up to 100%. But it did not on that day. Maybe the car is sorting itself out or the new update has something to do with it. Will wait to see how it goes this week.