Excessive battery drain while vehicle is parked and off

[JeremyS]

I’ve been experiencing a frustrating issue lately and hoping someone here will be able to point me in the right direction. My 2024 GT with performance upgrade is randomly draining a large amount of the high voltage battery while I have it parked at work, sometimes as high as 20% over the course of ten hours. I’ve ensured nothing is plugged in and still randomly have this occur.

Of course when I’ve taken it into the dealership and left it for a few days, they cannot replicate the issue so I’m finding myself a bit stuck here.
Additionally I’ve noticed I’m barely getting 2.0 mi/kWh while driving, which I had attributed to the colder weather, however I can’t imagine losing 20% charge while not driving is normal.

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[Snakebitten]

I think you should get you an OBD adapter and the car scanner app.

Take appropriate screenshots of the applicable PIDs to back up your experience.

For example. If there was record that the vehicle was at 80% SOC and 5400 miles.
And the next screenshot was 70% SOC and the mileage was still 5400 miles.......

See what I'm suggesting?

 

[JeremyS]

Yes I get what you are saying. Funny enough I did that last month (attached photos)
They told me it wouldn’t do much good if they can’t reproduce the issue.

 

[Mach-Lee]

I’ve been experiencing a frustrating issue lately and hoping someone here will be able to point me in the right direction. My 2024 GT with performance upgrade is randomly draining a large amount of the high voltage battery while I have it parked at work, sometimes as high as 20% over the course of ten hours. I’ve ensured nothing is plugged in and still randomly have this occur.

Of course when I’ve taken it into the dealership and left it for a few days, they cannot replicate the issue so I’m finding myself a bit stuck here.
Additionally I’ve noticed I’m barely getting 2.0 mi/kWh while driving, which I had attributed to the colder weather, however I can’t imagine losing 20% charge while not driving is normal.

How are you charging the vehicle? How often, to what percentage, what size charger, do you use departure times in the morning? Level 1 charger?

 

[cbcasas]

What are temps looking like? From your first screenshot it looks like it’s very cold/icy (yellow icon on dash). The battery could’ve recalibrated based on the temp and it’s now giving a “more accurate” guesstimate of range

 

[JeremyS]

In the mornings it’s averaging about mid 30s I would guess. I know range takes a hit when it’s cold, but when the battery is “acting up” I am lucky if I can get around 100 miles of range before it’s done.

 

[JeremyS]

How are you charging the vehicle? How often, to what percentage, what size charger, do you use departure times in the morning? Level 1 charger?

I charge every night (right now just level 1 at home with the included mobile charger ). I start the week at 90% and use roughly 12-14% charge one way to work. Charging over night nets me about 12-15% charge. I do use departure times.

when I first got the vehicle I would end my 4 day week at around 40% charge remaining when I pulled into the garage at home, but now I’m getting home on day 3 with like 10-15% max and I’ve started having to use public charging to supplement

 

[Mach-Lee]

I charge every night (right now just level 1 at home with the included mobile charger ). I start the week at 90% and use roughly 12-14% charge one way to work. Charging over night nets me about 12-15% charge. I do use departure times.

when I first got the vehicle I would end my 4 day week at around 40% charge remaining when I pulled into the garage at home, but now I’m getting home on day 3 with like 10-15% max and I’ve started having to use public charging to supplement

OK, your problem is caused by there not being enough "off time" for the BMS to accurately sense the state of charge of the HVB. The time at work seems to be the only time not trying to charge or discharge. The SoC is not actually dropping, the estimate of the SoC is simply being updated. The cells also need time to balance after charging has finished.

To avoid this problem, you'll need to use a Level 2 charger since Level 1 isn't keeping up with your needs. This will give enough off time to sense SoC accurately, and also the ability to warm the battery pack during charging.

 

[JeremyS]

Ok I think that makes sense and would probably explain why the issue didn’t crop up at the dealership as it wasn’t plugged in there. I am working on getting 240 installed as soon as I can.
Should I not be plugging in each night after I get level 2 charging going?

 

[westPhilly mach]

I have similar issue right now. 22 premium awd 22k charge at home with mobile charger. I chalked it up the cold weather.

 

[Mach-Lee]

Ok I think that makes sense and would probably explain why the issue didn’t crop up at the dealership as it wasn’t plugged in there. I am working on getting 240 installed as soon as I can.
Should I not be plugging in each night after I get level 2 charging going?

Yeah, you'll just have to deal with weird SoC readings until you get level 2 installed. With Level 2, you do want to plug in each night and charge to the same level (e.g. 80%), which should only take an hour or two. Since Level 2 charging will have enough power to finish, you'll have enough off time for accurate SoC readings (you can leave it plugged in after it finishes).

 

[vsguru]

Ok I think that makes sense and would probably explain why the issue didn’t crop up at the dealership as it wasn’t plugged in there. I am working on getting 240 installed as soon as I can.
Should I not be plugging in each night after I get level 2 charging going?

I (and many others here from what I've seen on many threads) charge every night. I have a 240v 48Amp charger and I plug in anytime I get back from anywhere. It was wired as a plug in (NEMA 14-50), not hard wired, which I kinda regret. The extra amps available with hard wired look tasty now!

Be sure to check your local electric company for possible rebates on 240v chargers. Mine was worth $399, so my charger was free! You'll never regret getting a level 2 charger, especially if it's free!

Enjoy your ride

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