Interesting fact - Power consumption

Mark Holmes

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I have just notice by looking at my centre screen (Volts and Amps) that the heated seat do not have any drain on the HV battery as I suspected, but I would have thought that the same would have been said about the headlights, but they do drain the HV battery on mine, it’s only pulling 1 amp, but all the same I was surprised all the same.
Can someone else verify this for me too to ensure that I’m not going mad??
 
I had a quick look.

With the HVAC on low I am predominantly showing 1 amp but it regularly cycles (very quickly) up to 8 amp and back down to 1 amp. Switching the heated seats on makes no difference.

It looks to me that both HVAC and heated seats are powered by the 12 volt battery. However, it also looks like the 12 volt battery is constantly being topped up from the HV battery.
 
I had a quick look.

With the HVAC on low I am predominantly showing 1 amp but it regularly cycles (very quickly) up to 8 amp and back down to 1 amp. Switching the heated seats on makes no difference.

It looks to me that both HVAC and heated seats are powered by the 12 volt battery. However, it also looks like the 12 volt battery is constantly being topped up from the HV battery.
I agree. I would think the HV battery is for propulsion and dc to dc charging of the 12v battery only. All other power requirements would come from the 12v battery.
 
Apart from the fans / heating and cooling system which definitely come from the HV as you can see a fairly obvious pull on the power system when switched on.
 
Apart from the fans / heating and cooling system which definitely come from the HV as you can see a fairly obvious pull on the power system when switched on.
Really! What is the heating system? It doesn't appear to be very efficient on the MG compared to the Mini e.
 
Not on mine, with both lights and high beam on and radio and seat heater.

Only putting on heater made a difference.

20201210_151401.jpg
 
Hmmmm interesting...will check again later and see if mine is the same as yesterday
 
I had faulty 12v battery which was replaced after car was 10 months old - but AA said if car won’t start just leave the power on as the main batteries charge the 12v and the car should start after a few minutes !
 
That’s good to know; don’t want to test this, but it makes sense. Thanks for sharing.
 
The AA advice seems a bit counter intuitive, if your 12V doesn’t have enough power, how do you power on? Pressing Power on(with foot on brake) an EV first starts the 12V electrical systems then wakes up the traction battery that then starts supplying charge to the 12V (that is a bit rudimentary, but along those lines).

I’ve had personal experience of this in my old Kia Soul EV during lockdown, if the 12V drops too low, the dashboard lights up like a Christmas tree and only jumping the 12V will get the traction battery to turn on (and then in turn to start charging the weak 12V). I only turn on my car with foot on brake, as I don’t want to deplete the 12V in accessory mode. I also carry a small power bank that acts as a jumper starter which I used successfully on my Kia to fix the issues during lockdown.
 
The AA advice seems a bit counter intuitive, if your 12V doesn’t have enough power, how do you power on? Pressing Power on(with foot on brake) an EV first starts the 12V electrical systems then wakes up the traction battery that then starts supplying charge to the 12V (that is a bit rudimentary, but along those lines).

I’ve had personal experience of this in my old Kia Soul EV during lockdown, if the 12V drops too low, the dashboard lights up like a Christmas tree and only jumping the 12V will get the traction battery to turn on (and then in turn to start charging the weak 12V). I only turn on my car with foot on brake, as I don’t want to deplete the 12V in accessory mode. I also carry a small power bank that acts as a jumper starter which I used successfully on my Kia to fix the issues during lockdown.
Carrying a small powerbank seems like a sensible precaution especially as a first time EV'er like me. Question though can I store it in the boot, or would I lose access to that if the 12v was depleted?
Also since I have never possessed such a thing any recommendations for a cheap/reasonably priced one. (don't want to spend a fortune on something I hopefully will never use :)
 
They are handy to have.....I have used mine to start ICE cars with a flat batteries.!
 
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