Battery Drain overnight while plugged in

[sdugan99]

Noticed last night that my car charged to 80% 239miles. Then while left plugged in overnight when I got in the morning it was down to 233. is this normal?

 

[thecloud]

Yes, it's normal. Essentially, parts of the car are always on (like a mobile phone) and will typically cause 5-6 miles of range to be lost overnight. This is known as "vampire drain." You can reduce the drain to a minimum (around 2-3 miles) by unchecking the "Always Connected" box in settings, and enabling Energy Saving mode.

 

[TexasEV]

Also note vampire drain occurs the same whether plugged in or not. The charging doesn't start again until the drop reaches a threshold-- otherwise the charging circuit would be running almost continuously.

 

[sdugan99]

Thanks all. I thought that was the case but have had the car a month and this was the first time I left in the morning and it wasn't full "80%".

So was a little curious

 

[thecloud]

Thanks all. I thought that was the case but have had the car a month and this was the first time I left in the morning and it wasn't full "80%".

So was a little curious

If you saw more overnight drain than usual, there might have been some extra activity.

1. Your car might be trying to download a software update.
2. Your car might be trying to upload data to Tesla's servers:
Model S is hogging upload bandwidth
Massive data uploads since 2017.34 2448cfc

 

[TexasEV]

If you saw more overnight drain than usual, there might have been some extra activity.

1. Your car might be trying to download a software update.
2. Your car might be trying to upload data to Tesla's servers:
Model S is hogging upload bandwidth
Massive data uploads since 2017.34 2448cfc

That doesn't cause measurable battery use. If it's getting colder, though, that could be another reason why rated miles appear lower.

 

[thecloud]

That doesn't cause measurable battery use. If it's getting colder, though, that could be another reason why rated miles appear lower.

If frequent network activity is keeping the car awake much of the night, I'm fairly sure that'll create a measurable difference. Owners who've used third-party software which polls the car continuously to gather data have mentioned noticing extra drain as a result.

But I agree that cold weather (causing the BMS to use more energy keeping the battery warm) is a likely suspect. Was the night in question colder than usual?

 

[sdugan99]

If frequent network activity is keeping the car awake much of the night, I'm fairly sure that'll create a measurable difference. Owners who've used third-party software which polls the car continuously to gather data have mentioned noticing extra drain as a result.

But I agree that cold weather (causing the BMS to use more energy keeping the battery warm) is a likely suspect. Was the night in question colder than usual?

Yes tempatures have been dropping here in the Mid-atlantic in the last few days. Car is garage kept so not as cold in garage as outside

 

[odguy]

Yes tempatures have been dropping here in the Mid-atlantic in the last few days. Car is garage kept so not as cold in garage as outside

Have your charge start so that it ends shortly before your departure time. The battery will be warm and you will be at 80%.

 

[sdugan99]

Have your charge start so that it ends shortly before your departure time. The battery will be warm and you will be at 80%.

Thanks for road trips I am taking fro Thanksgiving, and New years will definitely get it warm and fully charged right before leaving. Not a issue at all on my daily commute I think I have only been below 100 mies of range once. It was more curiosity then a worry about range.