Car trying to charge hourly

[surfrasch]

About two weeks ago I noticed a change in my charging, from my solar app.....I can see the car starting to charge for about 10 minutes, every hour on the hour exactly....for instance it will start at 1am, charge for 15min then stop, start at 2am for 15min, 3am for 15, etc etc. The first time I noticed it was Monday, I took a screen pic and it's attached. The peak you see in the morning every hour is the Tesla charging. I looked back at my historical usage and it happened late March also. I noticed it happened this morning also. So what's strange is it doesn't happen every day. The first time I noticed on Monday, I unplugged the car for a few hours and did a soft reboot. Upon hooking it back up that evening, it was fine. Details of my car:

Model 3 AWD Long Range
Delivered 2018, roughly 53k miles
Sitting in a garage, warm temps recently in NH (Lets say at least 50F in garage, warm is relative!)
Using a Tesla wall charger, charging at 48A when its charging.
Running 2023.6.8
I've got the charger set to roughly 50% all the time, leaving it plugged in.
Sentry mode is on, but shouldn't be running while at "home".....at least, it never did for the past 4 years. It's not recording videos in the garage anyhow.

The other weird thing I've noticed in the past two weeks, is it appeared to update on itself to 2023.6.8.....pretty sure I was on a lower version, can't remember which one....then one day I looked and I'm on the most recent version. Is there somewhere in the software that I can check my historical software versions and what day they were downloaded? Wondering if there's something strange going on with this 6.8 version.

Thanks for any advice.

 

[GtiMart]

Have you ever replaced the 12V battery? It might be going bad and the car needs to wake up often to charge it? Just a thought...

 

[surfrasch]

Have you ever replaced the 12V battery? It might be going bad and the car needs to wake up often to charge it? Just a thought...

yep, replaced preemptively at 34k miles before a long trip, didn't want to take the risk.

 

[GtiMart]

Pulling close to 3kWh every hour... and your SOC doesn't go past 50%? That means the car spends that 3kWh in the hour before it starts charging again. Even Sentry alone wouldn't consume enough to explain that, it's just 200-250w constant. Maybe climate is still running, as if there was still someone in the car?

 

[surfrasch]

it's a good point....I didn't notice that last time, but I'll specifically check that next time. But, it's kinda strange that it would try to charge exactly every hour, on the hour?

 

[surfrasch]

Just an added data point, yesterday late afternoon the car started topping off the charge again every hour. It appeared as though Sentry Mode was running in my garage even though it wasn't taking pictures. I walk in front of my car, no lights blink, then I tried to shake my car and the front lights blinked....but nothing recorded on the flash drive. Then I just turned off sentry mode completely, and it stopped trying to charge every hour.

I'm thinking no one else would notice this type of charging behavior unless they're monitoring their power usage ....in my case it's automatic with my solar system. Anyhow I'll keep watching this, I have to travel for a week or so, but when back I'll turn on sentry mode again and see if it activates in my "home" garage.

No one else really seeing this??

 

[GtiMart]

I have TeslaFi tracking everything happening with my car. I often leave it plugged for the whole night and it does NOT constantly charge every hour. Sentry mode is OFF in my case. Having Sentry on leaves the car awake and consuming a constant 200-250w so eventually, the car would need to charge a bit to top up that spent energy.

 

[surfrasch]

agreed, I've had the car over 4 years and never saw this happen.....that's why I'm a little freaked out.....I keep going in the garage to see if the climate is on......so far I haven't noticed that, it has to be sentry doing it, and maybe it's not recognizing my "home" location?

Do you know if there's a place where I can find my software version history? I could have sworn, I was looking at it for a couple weeks....at current version and seeing people getting a new version.....then all of a sudden I was on the new version and the app never came up and asked if I wanted to load it....could have sworn it did it on it's own.....I never approved a download. I'd like to look at that timing, to see if it correlates with my charging history.

 

[davewill]

I do know that consistently using a charge level below 80-90% can confuse the BMS quite a bit, causing it to report a lower range than the battery is actually capable of. Normally, there's enough hysteresis in the charge level that the car doesn't act like this. Is it possible that the BMS is getting confused about how low the charge has gotten? It could be that it thought it charged to 50% and really only charged to 48% so when it discharged 3kWh, it thought it was down enough to need to recharge. Or perhaps it's because 3KWh is a bigger percentage of 50% than it would be of 90%, and it just barely meets the threshold to cause a recharge?

When it doesn't act like this, how long is it waiting before it tries to top up?

 

[surfrasch]

Yes understood.....First two years of ownership I kept it at 80% in the garage, then after reading the multiple long battery range posts and seeing my range drop to roughly 290 I started keeping it to 50% all the time, and only going above that when I needed the range....last two years. The range has held to roughly 286 to 292 over this period of time, seems settled in now.

This behavior just started late March, I'd never seen it before.....and it's only this week that I figured out it wasn't a one time occurrence. Honestly I think it's software related, but we shall see. I'd love to see the day I got the latest update, not sure how to get that info?

 

[GtiMart]

Just as a data point, I have my car set to charge to 55% and plug again when it's around 45% so it really doesn't see much swing unless I diverge from my base pattern. This constant charging isn't happening.

 

[surfrasch]

Been doing it like this for years, something changed, just not sure what?

 

[AlanSubie4Life]

Pulling close to 3kWh every hour... and your SOC doesn't go past 50%? That means the car spends that 3kWh in the hour before it starts charging again.

Note that it is not pulling that much. The peak kW is 3kW.

So more like 750Wh per hour at most. Which is a lot. Hard to tell exactly how much without a numerical integration of the power data, but for sure it is a lot less than 3kWh per hour.

But doesn’t seem to be pulling the full 11.5kW regardless, this is more like 10A or something. (Would be interesting to see what the car screen says but it may not be possible to get…maybe in the app it would say?)

Anyway this could be software I suppose to top off Sentry Mode usage. No idea since I don’t have this software; I live in 2022.

There is a lot of weirdness around charge limits not being reached due to BMS etc. so they may be trying to adjust the behavior in the new release to more tightly hew to the set limit.