Top Up Not Respecting Charge Timer Setting

[mknox]

Here's something new:

I have Time of Use electricity rates where I live, so I use the charge timer on my car. In addition, my car seems to have a fairly high "vampire" drain, and the car will need to charge every day when left sitting (plugged in).

The car will respect the timer setting for the initial charge (I have it set for 1:00 am), but on subsequent days, it will just charge willy-nilly at any time of the day or night whenever it needs it.

In the past, each day I would see the car (or the app) simply say "Charge Scheduled for 1:00 AM" and then that day's top up would start at 1:00 am as it should. Now my top ups are occurring as often as not in peak electricity price periods.

I am on 8.0 (2.50.114) and just noticed this. Not sure when this started happening.

 

[jerry33]

I haven't found that to be the case. I'm on 2.44.130, but I don't recall it happening on earlier versions.

 

[TexasEV]

Top ups are only to replace vampire drain, so are relatively trivial amounts of electricity. As a practical matter I think we're talking about a difference of a few cents here.

 

[mknox]

I haven't found that to be the case. I'm on 2.44.130, but I don't recall it happening on earlier versions.

Yeah, I just noticed it this week, but usually don't have my car sitting for even one day without being driven. I know for a fact it didn't happen before, because I would track it on my energy monitor when away on vacation etc.

Top ups are only to replace vampire drain, so are relatively trivial amounts of electricity. As a practical matter I think we're talking about a difference of a few cents here.

My car uses an average of 3-5 kWh per day when ide. My On Peak rates are about double Off Peak. True it's not a lot of money, but the car should respect the timer settings as it did before.

 

[brkaus]

Change to protect the 12v battery?

 

[aesculus]

Now my top ups are occurring as often as not in peak electricity price periods.

I am on 8.0 (2.50.114) and just noticed this. Not sure when this started happening.

I noticed this too but it seemed to be related to me unlocking the car and even then I am not sure if the car was actually charging or not.

What I noticed is that the charging ring was solid green (not blinking) and the dash indicated the voltage and current, but I could not be certain it was actually charging or not.

I will try to look at it more this week.

 

[mknox]

Change to protect the 12v battery?

Doubtful. The 12v system is maintained via the DC-DC converter at all times whether the car is plugged in or not. The car's charging system only supplies the high voltage battery. One thought is that a "weak" or "bad" 12v battery may be needing more frequent top-ups via the DC-DC but in my case, I just recently had my 12v replaced and have not seen any appreciable change in vampire losses.

 

[mknox]

What I noticed is that the charging ring was solid green (not blinking) and the dash indicated the voltage and current, but I could not be certain it was actually charging or not.

Solid Green means the car is at it's set charge point and is not actively charging. Flashing Green (quickly when the SOC is low, slow when the SOC is high) means active charging. Solid Blue means the car is connected, in need of a charge, but is waiting for the scheduled charge period to begin.

 

[David99]

Your car seems to use a lot of energy just sitting there. But not unheard of.
I have mine set on schedule as well, but I guess I have never had it sit long enough to see it top off on its own. Must be a certain threshold before it tops off. One thing you could do is to unplug and replug right away any time during the day. This way it definitely will start charging again at the set time at night instead of waiting for the level of charge to drop. Not really a solution, I know.

 

[mknox]

Your car seems to use a lot of energy just sitting there. But not unheard of.
I have mine set on schedule as well, but I guess I have never had it sit long enough to see it top off on its own. Must be a certain threshold before it tops off. One thing you could do is to unplug and replug right away any time during the day. This way it definitely will start charging again at the set time at night instead of waiting for the level of charge to drop. Not really a solution, I know.

A couple of years ago, when I was away on vacation, I would see on my home energy monitor that the car was topping itself up to the tune of 2.5 kWh every other day. Now I see at least that much on a daily basis. Tesla has tested everything and can offer no explanation other than to say everything is working fine.

And yes, it's only an issue when the car sits for longer than 24 hours without being driven. This is very rare unless I'm away on vacation for example. And in that case, I wouldn't be able to unplug and re-plug anyway.

 

[NOLA_Mike]

A couple of years ago, when I was away on vacation, I would see on my home energy monitor that the car was topping itself up to the tune of 2.5 kWh every other day. Now I see at least that much on a daily basis. Tesla has tested everything and can offer no explanation other than to say everything is working fine.

And yes, it's only an issue when the car sits for longer than 24 hours without being driven. This is very rare unless I'm away on vacation for example. And in that case, I wouldn't be able to unplug and re-plug anyway.

My "theory" (hypothesis probably better term) is that as the 12V battery ages it requires more frequent "topping off" from the propulsion battery because it just doesn't take and hold a charge as well as when it was new.

Based on that, is your 12V battery relatively old?

Mike

P.S. I could be completely off base here, just been thinking about reasons why some cars have more vampire drain than others.

 

[David99]

My "theory" (hypothesis probably better term) is that as the 12V battery ages it requires more frequent "topping off"

That is an interesting thought.

 

[NOLA_Mike]

That is an interesting thought.

Meh, every once in awhile I have one. I guess that's it for 2017...

 

[mknox]

My "theory" (hypothesis probably better term) is that as the 12V battery ages it requires more frequent "topping off" from the propulsion battery because it just doesn't take and hold a charge as well as when it was new.

Based on that, is your 12V battery relatively old?

I had that exact same thought, and planned to ask Tesla about it at my upcoming "annual". Before my appointment occurred, I got a "Replace 12v Battery Soon" error and took my car straight in. They replaced the battery for me on the spot, and I had high hopes that this would fix my vampire drain problem. Unfortunately, it didn't. A couple of weeks later, when I had my car in for it's "annual", they said they checked everything and ran every test they could and found no issues.