Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Keeping an Infrequently Driven LFP Happy

This site may earn commission on affiliate links.
Me 2. But I will be driving it about 450 +/-mi a week. My commute is 52mi one way, so I see 1 supercharger visit a week and supplement with a 16amp home charger for the time being, until I have my own place and with a 32 amp circuit.
 
I just bought a ‘23 RWD and work from home, so will probably drive it only 50-100 miles per week. My plan is to charge to 100% only once A) charge has dropped below 40% and B) it’s the night before I plan to go somewhere the next day (I always go somewhere on Sundays, for example). At other times, I will probably keep it plugged in, but not charging. This will mean a variable SOC and probably only charging to 100% once or twice a month.
It’s gonna complain at you if you do that and keep shifting the charge limit back up to 100% I. My experience. I’ve regularly charged to 100% (2-3 times a week minimum). Currently seeing 266 miles of the original 272 after 7800 miles. Don’t think based on this thread it makes much difference.
 
  • Like
Reactions: freeAgent
I am an infrequent driver with a LFP M3, I drive around 100-150 miles a week. I charge to 100% once a week and 70% the rest of the days.

Some days I come back home with 55-65% battery and I'm set to charge it to 70% that day. Should I not charge and wait until I run it down to 30-40%, or just charge from 55-65% to 70%? What's the best practice in this case? Is there any benefit to running it down, then charging. Or should I just always be charging, even if I just need to go from 60% to 70%?
 
I am an infrequent driver with a LFP M3, I drive around 100-150 miles a week. I charge to 100% once a week and 70% the rest of the days.

Some days I come back home with 55-65% battery and I'm set to charge it to 70% that day. Should I not charge and wait until I run it down to 30-40%, or just charge from 55-65% to 70%? What's the best practice in this case? Is there any benefit to running it down, then charging. Or should I just always be charging, even if I just need to go from 60% to 70%?
The manual says there's no advantage in delaying charging your car. Keep your car plugged in.

If you have a choice, you should avoid deeper discharge.

Tesla recommends 100% charging for LFP to increase the accuracy of the battery gauge. That gauge is actually a guess-o-meter and there were quite a few complaints that the car died when there's still lots of range left on the battery gauge (actually the guess was wrong and that's why the car died because there's actually zero miles left).
 
I am an infrequent driver with a LFP M3, I drive around 100-150 miles a week. I charge to 100% once a week and 70% the rest of the days.

Some days I come back home with 55-65% battery and I'm set to charge it to 70% that day. Should I not charge and wait until I run it down to 30-40%, or just charge from 55-65% to 70%? What's the best practice in this case? Is there any benefit to running it down, then charging. Or should I just always be charging, even if I just need to go from 60% to 70%?

Haven’t personally tested this yet, but based on what I’ve read, I think the BMS will remain more accurate if you just wait until it gets down to 30-40% before charging back to 100%. The BMS can only gather calibration data when the car has been sleeping and not charging for a while. If you have Sentry mode on away from home and always charge to 70% at home, plus the occasional 100%, then the BMS will only ever get calibration data at 70% and 100% SOC. Two points isn’t really enough to build an accurate SOC curve estimate. In theory, it will be most accurate if it’s regularly charged to 100% and it can gather calibration data at varying SOC levels.

I recently saw a post from someone who charged their LFP pack to 70% on most days and 100% once a week, and after a while, their 100% charge was showing much lower (inaccurate). The solution for them was to start charging to 100% every time, but I personally think the problem was charging to a the same 70% value every day and not letting the BMS take calibration readings at other SOCs. I’m going to let mine fall to 30-40% before charging back to 100% and will see how it goes after a few months to a year.
 
  • Like
Reactions: DrChaos
I am also an infrequent driver with a LFP M3.

I drive around 100-150 miles a week. I charge to 100% once a week and 70% the rest of the days.

Some days I come back home with 55-65% battery and I'm set to charge it to 70% that day. Should I not charge and wait until I run it down to 30-40%, or just charge from 55-65% to 70%? What's the best practice in this case? Is there any benefit to running it down, then charging. Or should I just always be charging, even if I just need to go from 60%-70%?
I would run it down to 30-40% then charge back up to 100%. The benefit is lower average state of charge which will lower calendar degradation. Plus as mentioned, letting it sleep at different state of charges which will improve BMS calibration. Be sure to have sentry & cabin overheat set to off to let it fully sleep.
 
I am an infrequent driver with a LFP M3, I drive around 100-150 miles a week. I charge to 100% once a week and 70% the rest of the days.

Some days I come back home with 55-65% battery and I'm set to charge it to 70% that day. Should I not charge and wait until I run it down to 30-40%, or just charge from 55-65% to 70%? What's the best practice in this case? Is there any benefit to running it down, then charging. Or should I just always be charging, even if I just need to go from 60% to 70%?
As others have noted, consider letting it sleep at various states of charge for better BMS calibration.

Also, consider setting the charging to finish just before you drive off. Then, if you plug in as soon as you get home, it won't start charging until it has just enough time to recharge by the time you drive off the next day, giving it time to sleep at the lower state of charge you got home with.

Having charging finish just before you drive off also minimizes the time spent at higher states of charge when you do charge to 100%.
 
As an update, this demonstrates just how infrequently this car gets driven:

charging.jpg


My problem is that any advice based on time rather than miles, isn't appropriate for my situation. What I need is something like, "To keep the BMS system accurate, you should charge to 100% at least every 300 miles."

I wonder if anyone could answer this hypothetical: If I charge to 100% and don't drive the car at all, and the SOC gradually drops to 30%, will the BMS be relatively accurate at that point?
 
This is a good thread. I take delivery of a M3 rwd on February 28th🤞. I , too, will be only using the car occasionally and may only put on 10-50 miles weekly. Then, there will be times where we will take 100-400 mile trips

Has there been a consensus on charging habits?
 
This is a good thread. I take delivery of a M3 rwd on February 28th🤞. I , too, will be only using the car occasionally and may only put on 10-50 miles weekly. Then, there will be times where we will take 100-400 mile trips

Has there been a consensus on charging habits?
I’ve been charging to 100% daily. Covered over 3000 miles since early December and seen no effect on the estimated range. Still showing 270
 
I’ve been charging to 100% daily. Covered over 3000 miles since early December and seen no effect on the estimated range. Still showing 270
That is pretty good. LFP is a durable battery. I had a 2109 M3 with NCA battery. I lost 22 miles with only 18,000 miles. I took good care of the battery and hardly ever charged to 100%. Yet I still lost 22 miles in a short time. That is why I bought this M3. No more games.

Let the SOC go down to 30-40% and charge it back up to 100%. Some rules for me will be:
1. don't charge to 100% unless you drive somewhere.
2. You can have it drop down below 30% on a trip but don't make it a habit.
3. And, most importantly, don't worry too much about it.
 
Last edited:
That is pretty good. LFP is a durable battery. I had a 2109 M3 with NCA battery. I lost 22 miles with only 18,000 miles. I took good care of the battery and hardly ever charged to 100%. Yet I still lost 22 miles in a short time. That is why I bought this M3. No more games.

Let the SOC go down to 30-40% and charge it back up to 100%. Some rules for me will be:
1. don't charge to 100% unless you drive somewhere.
2. You can have it drop down below 30% on a trip but don't make it a habit.
3. And, most importantly, don't worry too much about it.

100% is not as bad as people think.
In many cases, 100% is equal to 80 or 90%.
LFP is not sensitive for large cycles, meaning that you can do 100% without any issues or any noticeble increase in wear.

For LFP, i do not really see why not to fiölow the Tesla advice to keep the BMS updated and the buffer low ( its dynamic, increases if the BMS is unsure of the SOC level).

Below 30% is very very safe.
Below 20% is very very safe.
Below 10% is very very safe.
The lower the SOC, the less degradation.

The ONLY issue with low SOC is the possibility for range anxiety so dont go lower than what feels OK for you.
 
  • Like
Reactions: DrChaos
This is a good thread. I take delivery of a M3 rwd on February 28th🤞. I , too, will be only using the car occasionally and may only put on 10-50 miles weekly. Then, there will be times where we will take 100-400 mile trips

Has there been a consensus on charging habits?

The problem is that our situation is so unusual that there isn't much data or interest. I'd like to hear a Tesla tech's advice if our situation were fully explained.