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Discussion Starter · #1 ·
Does anybody know if it's possible to run the heater and not flatten the 12v battery whilst rapid or fast charging, would I need to press the brake and start button to ensure the 12v battery is being charged, especially since the car has been updated and can now fast charge whilst unlocked?
 

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When plugged in to a rapid charger, I always put my foot on the brake to turn the car on and enjoy the heating / cooling. I figure having it on keeps the 12v battery charged as it would under normal conditions. There are many warnings on the dash - "car plugged in" Yes, I know, I plugged it in myself. "HV battery disconnected" Yes, I know, I plugged you in. Sitting in front of the charger, you can really notice how bright the DRLs are too.

I've been plugged in and heating for nearly an hour before without a problem - other than that particular slow rapid charger!

Not sure about fast charging, had no reason to try it yet.
 

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Being turned on also allows you to see the charge rate.
 
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Although sadly not the percentage!
 
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On mine I can see the miles increase. 130 is about 80% I think?
 
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Does anybody know if it's possible to run the heater and not flatten the 12v battery whilst rapid or fast charging
It will be fine. The heating system runs off the high voltage battery, so heating won't drain the 12V directly. Plus with the high voltage system being active for the heating, the 12V battery management should also be active and continuously or periodically charging it.

The only downside is that any energy used by the heating will effectively reduce the rate of charge. This is most impactful on AC charging where it would represent a significant % of the power being delivered anytime the resistive heater is switched-on by the climate control (which could be up to 3kW).
 

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It will be fine. The heating system runs off the high voltage battery, so heating won't drain the 12V directly. Plus with the high voltage system being active for the heating, the 12V battery management should also be active and continuously or periodically charging it.

The only downside is that any energy used by the heating will effectively reduce the rate of charge. This is most impactful on AC charging where it would represent a significant % of the power being delivered anytime the resistive heater is switched-on by the climate control (which could be up to 3kW).
@DougM are you sure. I’ve seen this video about heating the car draining the 12V battery. It also shows how to use the emergency key if the car battery is drained

 

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@DougM are you sure. I’ve seen this video about heating the car draining the 12V battery. It also shows how to use the emergency key if the car battery is drained

Yes, and I was plugged in at home at the time, but not charging.
 

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Yes, and I was plugged in at home at the time, but not charging.
Mike, but you said ”The only downside is that any energy used by the heating will effectively reduce the rate of charge”

I don’t have my ZS EV yet, due to pick it up this week, but am really confused about heating the car while plugged in and charging. It’s just not clear if it can be done and if so what steps you need to do to get it working properly

If anyone with the BMS & Comfort2 upgrades could post the actual steps you take when you plug in to Rapid or Fast charger and charge whilst heating the car I think it would be a great help to everyone 🙏🙏🙏🙏
 

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..
 

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Discussion Starter · #13 ·
Thanks for your replies, I tried rapid charging last night, and turned the car on whilst pressing the brake, the heater worked fine and from the charge rate on the dash continuously fluctuating up and down can confirm the element for the heater does run of the HV battery circuit, but everything else in the car lights/radio including the fan blower for the heater runs off the 12v battery, which I was aware wasn't being charged back up looking at the 12v battery gauge, although the fan for the heater won't consume a lot of electricity, I'd turn everything else off if I needed the heater on and then probably only use it with the fan set to low but the heat set to max for 10 minutes as I wouldn't want to be left with a low 12v battery.

I could tell the 12v battery wasn't being charged, as when the volt gauge shows 14v with the lights off it is being charged, it goes down to about 13v with the lights on normally, but as soon as you turn the lights off, it goes back up to 14v, so the gauge measures the voltage in the 12v circuit. Whilst plugged in rapid charging the voltage meter never showed 14v with the lights off, only 13v then it eventually lost another bar which shows it wasn't charging. But I had it on for 40 mins before that happened, so I'd say having the heater on for 10 mins is fine, so long as you've got a good 12v battery, but be careful not to flatten it below 12v as then the car may not switch on.
 

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Yes, the 12v gauge shows the state of the charging circuit when the car is on or connected to a charge, rapid or fast.

It only seems to show the 12v voltage when the car is on but not in ready mode.

To use the heater while rapid charging you just make sure the car is turned off, start the rapid charge then turn car on pressing the brake pedal as per normal. It will remind you that you can’t drive and it won’t be in ready mode. Then turn the heater on. No special tricks. Just like I have done in my previous Leafs.
 
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@MikeProcter & @Chris86 thanks guys, much appreciated. Only two more questions 😜

1) After you connect the fast/rapid charge cable do you need to lock the car to get the charging underway, then when you want to heat car (ie you’ve gone for coffee and you want to pre-heat the car for family) you unlock the car, get in, touch brake pedal, turn on heater and et-viola you have a warm & charging car?

2) with the heater on can you re-lock the car to go finish your coffee and keep heating/charging car or does it have to stay unlocked or with you in the car?
 

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@MikeProcter & @Chris86 thanks guys, much appreciated. Only two more questions 😜

1) After you connect the fast/rapid charge cable do you need to lock the car to get the charging underway, then when you want to heat car (ie you’ve gone for coffee and you want to pre-heat the car for family) you unlock the car, get in, touch brake pedal, turn on heater and et-viola you have a warm & charging car?

2) with the heater on can you re-lock the car to go finish your coffee and keep heating/charging car or does it have to stay unlocked or with you in the car?
At home I only have a granny charger. when it starts charging I can turn on the heating, lock the doors and go indoors. Handy these cold mornings! This has only been possible since software updates were installed.
 

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I am sure Mike will correct me if I am wrong, but I was of the opinion that you could always run the heater with the car locked or unlocked and run the heater when charging from a RAPID unit.
But when charging on a 7kw public fast post or a home wall box, the car had to be LOCKED to continue with the charge.
Unlocking the car would then interrupt the charging cycle.
But, if the car has received the very recent BMS update ( that will believe is MG service bulletin S015 ) then the car WILL continue charging on a 7kw unit even when the car is unlocked.

The energy provided for heating the cabin, is provided from the large HV traction battery, but the power required to run the low voltage heater blower motor, is supplied from the 12 volt lead acid battery.
The car can be heated directly from the HV battery when the car is at rest / parked up, but remember you need the car in the fully booted "Ready" status or you will risk fattening the 12 volt battery.
It is possible to run the heater when the car is powered down, but I would advise strongly against this type of this practice.
 

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@MikeProcter & @Chris86 thanks guys, much appreciated. Only two more questions 😜

1) After you connect the fast/rapid charge cable do you need to lock the car to get the charging underway, then when you want to heat car (ie you’ve gone for coffee and you want to pre-heat the car for family) you unlock the car, get in, touch brake pedal, turn on heater and et-viola you have a warm & charging car?

2) with the heater on can you re-lock the car to go finish your coffee and keep heating/charging car or does it have to stay unlocked or with you in the car?
That’s more than 2 questions!!
1a. No. Should not need to lock at a rapid.
1b. Yes you can switch the car on and put the heater on when you have used the MSA facilities.
2. no. You can’t lock the car with the car running using the remote.

Caveat: I’ve not tried leaving the car unattended charging in a public place with it switched on with the heating on and then tried to lock it with the emergency key.
 
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Discussion Starter · #19 ·
Rodgerdee how do you manage to lock the car, with the car turned on heating with the granny charger, I try and lock mine and it just beeps it's horn, probably to warn that it's switched on and your trying to lock it, I would like to turn it on whilst plugged in and lock it, whilst I go inside while it defrosts with the heater on, mine just doesn't want to lock whilst it's switched on.
 

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I’m not convinced it uses power when AC charging. I would like to be wrong. I know it does from DC charging.

As for locking the car, use the emergency key.
 
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