Just FYI, you can see more precise battery level in the service menu. Go into the software submenu in the settings, press and hold the "Model 3" branding, and enter "SERVICE" when the dialog box pops up, then go to the battery section I think.
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Model 3 SR+ LFP Battery Range, Degradation, etc Discussion
- Thread starter Baluchi
- Start date
Just FYI, you can see more precise battery level in the service menu. Go into the software submenu in the settings, press and hold the "Model 3" branding, and enter "SERVICE" when the dialog box pops up, then go to the battery section I think.
One reason is that below 20%, the car stops charging the low voltage battery from the high voltage battery, and once the in car computers use up all of the low voltage battery, your car won’t start. And in most EVs and Teslas older than the past couple years, the low voltage battery is a different type of battery that doesn’t like to be drained all the way, and doing so usually kills it and requires replacement.
Another reason is that the car likes to do certain things to maintain battery health and to keep the battery ready for use. For example, in extreme cold, the car may use some battery to warm the battery and keep it from getting too cold to be used.
There are probably other reasons, but I think most of it boils down to the fact that we aren’t truly storing our batteries. The batteries are still connected to the car and expected to do things occasionally, whereas in lab tests they can completely disconnect the batteries.
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AlanSubie4Life
Efficiency Obsessed Member
Not correct! This would be really bad!
Not sure that there is any evidence of this. Battery can be discharged in BBC extreme cold. Cannot be charged even when just modestly cold.
But off the top of my head, if your expected degradation was about 5%, while mine was closer to 7 percent, then it seems possible that our capacity loss could be equivalent because your high mileage is kind of balanced out by my 35%-55% charging style. As opposed to calendar loss simply being such an overriding factor in degradation that it completely dwarfs other factors…
Exactly!
My 12V battery has had supply all the time, even down to -2% SOC.
I’d say the LV batt is charged until the HV batt shuts down to protect itself.
I have seen a lot of rumors about this, 6% and 20% etc.
The LV bat is 45Ah? 12x 45 = 0.5kWh, and as a lead acid battery get damaged from low SOC it would get empty damaged quite fast as the car use ~200W when not sleeping. A couple of hours below that level would be enough to empty the car, driving or parked.
I have had my car sleeping below 5-10% many nights and down do 0% a few.
The manual also states that the LV batt stops being charged when the SOC is below 0% / too low.
The car does not actively heat the battery when the car is parked/not in use and/or not preconditioning.
I have checked this numerous times at work where I have my car parked up to one week at the time, and in cold Wx the battery eventually reach the same tempersture as the ambient.
In my case its not uncommon to se the battery being colder than the ambient as the ambient temp varies and can go up but the battery temp will climb slowly.
The car shows a lower SOC number when the battery is cold, to show a compensation for the energy needed to heat the battery etc.
We can always drive even if the car has been cold soaked to really low temps, the battery starts heating when we start to drive at the latest. (Preconditioning will heat the battery if it is cold so thats a good Practice as cold cycles causes more wear.
Just a reminder that the "degradation" from charging in a narrow voltage band as shown in the chart is not real degradation. It recovers when you start charging a wider range of levels. Of course, cumulative charging cycles and a high resting/average SOC will still cause real degradation.
Thomas Edison
Active Member
My brand new LFP car, parked with sentry mode turned off. The car loses 7-8% per day. I don’t even open the app to wake the car up. Anyone know what the problem might be?
AlanSubie4Life
Efficiency Obsessed Member
No. There must be something running that's draining power.
My car can be parked for several days at a time with almost no range loss.
Check the energy screen's Park tab (shown in this video starting at 2:37) to see if it highlights any particularly large source of drain while parked:
RichAZ/CapeCod
Member
Thomas Edison
Active Member
Thank you both for the tip. I didn’t specify earlier, but when I said sentry mode was off, I meant excluding home was active. And apparently it wasn’t working properly, because it looks like sentry mode was the culprit. 81 miles in 10 days.
Candleflame
Active Member
the manufacturers do recommend that. With the exception of I think Panasonic (which recommends storage at 30-50% at 15C) most manufacturers recommend discharging the battery to 0% and then freezing them. Possible that panasonic is more consumer oriented.
there was a crib sheet available here before of like 10 manufacturers and what their advice for storage is.
Tesla recommends storage of all battery types (in the EPA certification application) as far as I can see.
No, much of it depends on your driving style. Personally, I'm terribly under capacity for my range, according to Teslafi. I'm only at 8691km (5400mi) and 424km (263 mi) max range after a year of ownership, so I'm suffering more from calendar aging than wear-and-tear.
I’m exactly like yours, I’m using Tessie on my ‘23 RWD that I picked up in February. Very sharp linear line, only 1,500 miles so far. I’ve supercharged twice, mainly L1 until I got my L2 2 weeks ago. Only 8.5 cycles. Pretty much just charge to 100% once a week now. Now at 268.5 miles. This is a lease so I might just keep charging to 100%, for science.
Thanks for the correction. Guess I misremembered and was thinking about the percent when Sentry mode stops working. Sentry mode stops working at 20%, low voltage battery charging stops at 0%. But even though I got the percentage wrong, the reasoning stands, because the comment I responded to was asking why they shouldn’t leave the car at 0%.
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Are you sure about that? There could be some logic where the BMS only actively heats the battery for 24 hours or something before giving up and conserving energy, which could explain why you see temps reach ambient eventually when you leave it for a week.
I think this section of the manual is what led me to believe the car may use battery to keep the battery warm while parked. The way it says “to keep the battery warm” made me think this is not talking about preconditioning.
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