Pre heating battery and car query

[Pinnelli]

New to owning any EV and in my case MG ZS Long Range

Granny charger only whilst waiting on charger installation.

Set to charger for 4 hours in night on EV tariff., finished at 4:30 am. Will still be left plugged in

Now I need car at 6:30, I set pre heat battery in ismart app to come on 1 hour before. Question? Does that then use EV battery or switch my charging source back on?

Serving related question. It’s minus 4°C tonight so nice to defrost windscreen etc, maybe preheat car. Charging finished at 4:30am as above post will de ice / heating car drain EV battery or use brain and switch to pulling house supply?

Thanks

 

[Lovemyev]

If your car is still connected to your supplied Granny unit, when your request to heat the cabin is requested, it should reactivate the the Granny, in an attempt to back fill the demand required to heat the cabin and help preserve the range.
However, your low powered Granny lead will struggle to replace the energy used to heat the cabin, as the heater ( when in use ) consumes a lot of energy !.
Using the battery heater is very energy hungry also !.
I would turn off this function TBH.

 

[Pinnelli]

Thanks very useful so in essence pre heat car or the battery usues the EV battery , not the charging source, which is a shame. But the actions should reactivate the the charging of its outside the scheduled charge ?

 

[blippy]

In my experience 10 or 15 mins is enough

 

[Lovemyev]

Thanks very useful so in essence pre heat car or the battery usues the EV battery , not the charging source, which is a shame. But the actions should reactivate the the charging of its outside the scheduled charge ?

If you are still connected to your A/C wall box and you command the preheat of the cabin, it will restart the wall box to try avoiding any loss in range.
If you are disconnected from the A/C supply, then yes the power to heat the car is coming from the traction battery.

 

[Whiskery]

This is all very interesting. This morning as an example, the car had been plugged in all night and had finished charging at 0530. At 0830 I wanted to preheat the cabin and although I was still plugged in to the Ohme wall box, I still lost about 2% range.

It didn't matter this morning as I am working from home but on days where I need to go into the office In Pembroke (I live in Swansea) it is a 100 mile roundtrip so I need that extra range as I am a standard range ZS Mk2 / 22 plate.

Any thoughts as to why it didn't start up the A/C charging rather than using the traction battery?
I'm on Octopus Go and use the Ohme app to set the required charge if it makes a difference.

Thanks!

 

[Lovemyev]

This is all very interesting. This morning as an example, the car had been plugged in all night and had finished charging at 0530. At 0830 I wanted to preheat the cabin and although I was still plugged in to the Ohme wall box, I still lost about 2% range.

It didn't matter this morning as I am working from home but on days where I need to go into the office In Pembroke (I live in Swansea) it is a 100 mile roundtrip so I need that extra range as I am a standard range ZS Mk2 / 22 plate.

Any thoughts as to why it didn't start up the A/C charging rather than using the traction battery?
I'm on Octopus Go and use the Ohme app to set the required charge if it makes a difference.

Thanks!

When preheating the cabin direct from the traction battery, I would expected the reduction in range to be much larger than 2% to be honest
Using the heater set at about 22 - 23 degrees, is likely to instantly kill off about 10 miles plus from your predicted range.
The cabin heater is a hungry beast and demands a lot of energy from the HV pack.
The fan blower motor is powered from the 12 volt battery under the bonnet though.
Are you sure the wall box had not been triggered again ?.
If you have a home energy meter, you will see the energy being drawn if the wall box kicks in !.

 

[Gadget Geek]

I would imagine if the Ohme charger had set times to charge, it would not go beyond those times, even if the traction battery is losing charge to the heater. Try letting the timer in the car control the charging and see if that works.

 

[Whiskery]

Thanks for the suggestions guys, I'll look into these options