Airport parking in Winter. -3 to 3°C

[bdeithrick]

So I am parked at the airport for 3 weeks. It’s -2°C some nights. I’m confident the battery is in good condition as I use smart charger the odd time to condition it.
Question is.

If I log in once a week to preheat the car to low enough temperature. Will the action start to charge the battery ( aux / 12V ) in the time frame. ?
Does preheating, charge the battery ?


I’m sure it does, but don’t want to be that guy logging in checking everyday. Let it rest and save what energy it’s got . Thanks

 

[Ian Key]

You don't need to preheat the cabin to charge the 12V battery. The car should do it itself with no intervention from you. Also when the car is preheating the cabin the lights are on which not only draws attention to the car but could run down the 12V battery.

 

[DBedford]

Don’t access the car to preheat or check status it will drain your 12V battery. Make sure your 12V battery booster is accessible and fully charged before you leave the car.

 

[Robf]

Best to disconnect -ve terminal as per manual. I fitted the below to make it easy, works fine.

https://www.amazon.co.uk/Universal-Disconnect-Terminal-Isolator-Vehicles/dp/B075CK7W3Z/ref=asc_df_B075CK7W3Z/?tag=googshopuk-21&linkCode=df0&hvadid=218081924305&hvpos=&hvnetw=g&hvrand=8300943144303884565&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006810&hvtargid=pla-730116208456&mcid=4dd8c16e77a93d9595dcf060c482bd4e&th=1

 

[lsb777]

So I am parked at the airport for 3 weeks. It’s -2°c some nights. I’m confident the battery is in good condition as I use smart charger the odd time to condition it.
Question is.

If I log in once a week to preheat the car to low enough temperature. Will the action start to charge the battery ( aux / 12V ) in the time frame. ?
Does preheating, charge the battery ?


I’m sure it does, but don’t want to be that guy logging in checking everyday. Let it rest and save what energy it’s got . Thanks

This is always a bit of a strange situation. We drive these EVs with a massive traction battery underneath which gives the small amount of power needed to keep it's little 12V cousin going as there is no alternator like in an ICE vehicle. Surely the 400V/800V main battery is programmed to donate a little drop if it senses the 12V is running low, even when parked up? This would make sense as it's been mentioned elsewhere to leave your EV with at least 50% if parking up for holiday or similar and not using? Maybe it's just the more expensive cars that do this?

 

[siteguru]

The MG4 does top up the 12V as needed, but anecdotal evidence suggests that leaving the car with an SoC of less than 50% means it doesn't do so. (Why MG seem to have chosen this SoC is anyone's guess ... even 20% should be more than enough as topping up the 12V uses a comparatively minuscule amount of power energy).

 

[Torryhun]

I left my 4 SE LR at Edinburgh Airport for 14 days @ 35% Soc, on return 12v battery had dropped by •3 of a volt.

 

[Dodgy]

Best to disconnect -ve terminal as per manual. I fitted the below to make it easy, works fine.

https://www.amazon.co.uk/Universal-Disconnect-Terminal-Isolator-Vehicles/dp/B075CK7W3Z/ref=asc_df_B075CK7W3Z/?tag=googshopuk-21&linkCode=df0&hvadid=218081924305&hvpos=&hvnetw=g&hvrand=8300943144303884565&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006810&hvtargid=pla-730116208456&mcid=4dd8c16e77a93d9595dcf060c482bd4e&th=1

I have a similar product on order to simplify the battery disconnection process as we're regularly away.
I'm assuming that on departure once you've switched the battery off and closed the bonnet you need to lock the driver's door with the key? I'm guessing it also effectively precludes activation of the car's security system? What is your experience/understanding of how this works?

 

[tsedge]

The MG4 does top up the 12V as needed, but anecdotal evidence suggests that leaving the car with an SoC of less than 50% means it doesn't do so. (Why MG seem to have chosen this SoC is anyone's guess ... even 20% should be more than enough as topping up the 12V uses a comparatively minuscule amount of power).

I suspect this is a bug. We aren't short of them.

 

[Ian Key]

Perhaps the forum would be better being called MG4 Entomologists?

 

[MG Fred]

I parked at heathrow for about 3 weeks from 7th Dec to 24th Dec. Charge on main battery 62%. On my return 2.5 weeks later the charge was 61%. And no problem getting home. I didn’t access the car during the holiday until a day before the end, where I guess it was in a deep sleep mode as mobile access was unavailable. 190 miles round trip in winter with no need to charge until I got home. Ideal.