Battery discharge when idle?

Tigger · Jan 3, 2023

I was stunned to read in the Tesla 3 Owner's Manual that the battery can lose charge at the rate of 1% every day!

"Even when Model 3 is not being driven, its Battery discharges very slowly to power the onboard electronics. The Battery can discharge at a rate of approximately 1% per day, though the discharge rate may vary . . .
[if Model 3 is left at an airport] over a two week period (14 days), the Battery may discharge by approximately 14%."

I decided to test my Trophy's battery to see if it did the same thing. On December 29 it registered 68%, and this morning (January 3) it still registers 68%. So whatever loss there has been over 5 days, it is less than 1%. (I have to drive it today, so that ends the experiment.)

Can anybody else confirm this? And people with Teslas: is this 1% loss really true?

Sloucher · Jan 3, 2023

My son has a Model 3, and he has remarked on a 1% per day discharge before.
I left my Trophy with 63% in it over the Christmas break and it was at the same percentage yesterday.

VAG · Jan 3, 2023

Tesla is draining quite a lot of power when powered "OFF", because of the "Sentinel" function and cameras that are registering when the car is OFF. I don't think that the MG4 is concerned about so much discharge, when not used.

Cocijo · Jan 3, 2023

Tesla can use 3 monitoring cameras whilst parked, plus Wi-Fi for OTA etc when needed, but it does ‘sleep’ at certain times saving some discharge, and if HV is low the monitoring function is disabled. I’ve never really found it to be an issue - it automatically keeps the 12v charged - and the HV pack as long as it has a reasonable charge can easily run the items needed when switched off. Tesla are very good at the auto-management of batteries.

smbmetal · Jan 3, 2023

I wish my car had a Sentinel function after an attempted break in over the holiday period. I'd happily take a 1% per day battery drain to be able to see the footage.

troopercooper · Jan 3, 2023

Sloucher said:
My son has a Model 3, and he has remarked on a 1% per day discharge before.
I left my Trophy with 63% in it over the Christmas break and it was at the same percentage yesterday.

I've been wondering this for a few days now and assumed the worst but reading these comments is giving me a lot of relief. I travel a lot and was worried during times away the car would just vampire drain. Thanks all for confirming!

Sloucher · Jan 3, 2023

smbmetal said:
I wish my car had a Sentinel function after an attempted break in over the holiday period. I'd happily take a 1% per day battery drain to be able to see the footage.

Hopefully the attempt was unsuccessful?

Ryan · Jan 3, 2023

Mines always shown the same percentage even after a few days parked up

I was surprised as I was expecting it to maybe have lost a percent or two in that time

smbmetal · Jan 3, 2023

Sloucher said:
Hopefully the attempt was unsuccessful?

Yes it was - scared the bar stewards off!

Cocijo · Jan 3, 2023

You can roughly put some numbers on it. If pack is 61kwHR then 1% drain is c600watts/day - which is quite a lot for a car parked up. As the MG4 had no camera monitoring I would be very surprised if it uses a fraction of this amount when sleeping.

Cocijo · Jan 3, 2023

smbmetal said:
I wish my car had a Sentinel function after an attempted break in over the holiday period. I'd happily take a 1% per day battery drain to be able to see the footage.

What car did they try break in to?

smbmetal · Jan 3, 2023

Golf GTI

TheArcher · Jan 4, 2023

smbmetal said:
I wish my car had a Sentinel function after an attempted break in over the holiday period. I'd happily take a 1% per day battery drain to be able to see the footage.

Some dashcams have that function as an option. Nextbase and Viofo are worth checking - no doubt others too. Of course they only point one way.

siteguru · Jan 4, 2023

You can get front dashcams which also have an interior-facing camera? (e.g. Ashley Neal's vids on his YouTube channel often show split screen where front, rear and interior cameras are all integrated/edited onto the same display).

memo · Jan 4, 2023

TheArcher said:
Some dashcams have that function as an option. Nextbase and Viofo are worth checking - no doubt others too. Of course they only point one way.

I bought a viofo A139, 3 channel, with permanent wiring kit, this has front, rear and internal cameras.

Cocijo · Jan 4, 2023

memo said:
I bought a viofo A139, 3 channel, with permanent wiring kit, this has front, rear and internal cameras.

Do they all work when parked?

memo · Jan 4, 2023

Cocijo said:
Do they all work when parked?

Yes they all work in parking mode. You can, if you wish, disable the interior camera.

troopercooper · Jan 4, 2023

memo said:
Yes they all work in parking mode. You can, if you wish, disable the interior camera.

Have you also used the hardwire kit? Is that possible on the MG4, to get a constant power supply?

memo · Jan 4, 2023

troopercooper said:
Have you also used the hardwire kit? Is that possible on the MG4, to get a constant power supply?

I haven't got my mg4 yet, still waiting

I have this in my 4x4 at the moment. But I cannot see why you could not install in the mg4, that's my intention "when" I get it. Other people here on this forum have installed a dashcam in the mg4 it's no different than any other car in that respect still has a 12v battery and a fusebox. In fact this thread:

Dashcam install

Had my dashcams professionally reinstalled today. For anyone interested they were able to use empty live and switched live slots in the fuse box rather than tapping onto existing fuses. He installed a battery monitor to ensure voltage doesn't drop too low. I will try and get the pictures and...

www.mgevs.com

Paul V Smith · Jan 8, 2023

Tigger said:
I was stunned to read in the Tesla 3 Owner's Manual that the battery can lose charge at the rate of 1% every day!

"Even when Model 3 is not being driven, its Battery discharges very slowly to power the onboard electronics. The Battery can discharge at a rate of approximately 1% per day, though the discharge rate may vary . . .
[if Model 3 is left at an airport] over a two week period (14 days), the Battery may discharge by approximately 14%."

I decided to test my Trophy's battery to see if it did the same thing. On December 29 it registered 68%, and this morning (January 3) it still registers 68%. So whatever loss there has been over 5 days, it is less than 1%. (I have to drive it today, so that ends the experiment.)

Can anybody else confirm this? And people with Teslas: is this 1% loss really true?

I charged my Trophy to 100% battery, ready to do a long journey to visit family over Christmas. Unfortunately we both got the flu virus and was stuck at home. The car was left on our drive for 10 days and it was still registering 100% when I eventually went out for a drive.

Battery discharge when idle?

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