MG ZS EV HV Battery shut off

[KasEV]

OK. Thanks @MG Technician.
Good to know but I still do not see how and why one can have a flat 12volt if the HBV is full or adequately charged in normal use but given that it can happen as an unlikely event it is good to know that one can jump start.
More importantly I think one should know that if both 12BV and HBV are flat then jump start achieves no purpose.
I believe that the AA approach is to apply a power pack. Why?.... If I correctly understood what the AA patrol have said to me their preference is to apply a power pack through the charging port in all low power situations both 12BV and HBV. This equates to an equivalent of normal fast / rapid charging the EV for several minutes. The AA so far as I understand it do not jump start EV's in the normal understanding of Jump Start.
Anyway, so far as jump starting is concerned @MG Technician you mention that the donor car should not be running.
I am not sure but I think the correct advice is that both cars should be off at the beginning. Establish connection red cable first and after the connection has been made with both cables securely, you start the donor car first. Then you start the receiving car and keep both cars running for 2 to 5 mins then put the donor car off before removal of cables black cable first.
@Chrispydoc and others have more experience in jump starting so I am sure they will correct us if if we are both wrong.

 

[Kithmo]

 

[Mgkev]

When my Prius PHVs’ 12v battery went flat the AA guy jumped it with a booster pack.

 

[MG Technician]

OK. Thanks @MG Technician.
Good to know but I still do not see how and why one can have a flat 12volt

" The HV battery and dc to dc convertor will only charge the 12volt battery when in ready mode. I've had many 12 volt batterys lose charge when the E
New EV's have been sitting in storage with the 12v battery left connected."

if the HBV is full or adequately charged in normal use but given that it can happen as an unlikely event

" only unlikely if you use and charge the vehicle regularly"

it is good to know that one can jump start.

"Its not jump starting. Your only applying a substitute 12v feed which allows you to power up the vehicle which will then be taken over by the HV battery once in ready mode."

More importantly I think one should know that if both 12BV and HBV are flat then jump start achieves no purpose.

"you cannot fully drain the HV its not possible. However you can discharge it to the point it will the shut off to stop damage.
Which will no longer allow drive."

I believe that the AA approach is to apply a power pack. Why?.

" THE AA plug into your car to charge the HV battery to get you going again. It scares me how much the public trust the AA over a trained technician. I've had customers rage at me because of rubbish an AA breakdown operator said. "

... If I correctly understood what the AA patrol have said to me their preference is to apply a power pack through the charging port in all low power situations both 12BV and HBV. This equates to an equivalent of normal fast / rapid charging the EV for several minutes. The AA so far as I understand it do not jump start EV's in the normal understanding of Jump Start.

" ypur right they don't their only charging up the HV battery because who ever was driving it was silly enough to drive it without sufficient charge for their journey"

Anyway, so far as jump starting is concerned @MG Technician you mention that the donor car should not be running. "Yes not running. Supplying a 12volt feed from another 12v battery which allows the ev to be powered up. Nothing to do with HV charging. "If your 12v battery goes flat your HV battery could be 100% charged but you will not be able to power up the vehicle. I have had many customers saying the HVB if flat but its been the 12v battery because they left it powered up but not in ready mode."

I am not sure but I think the correct advice is that both cars should be off at the beginning. Establish connection red cable first and after the connection has been made with both cables securely, you start the donor car first. Then you start the receiving car and keep both cars running for 2 to 5 mins then put the donor car off before removal of cables black cable first.

"your talking about starting an engine powered vehicle"
"completely different in every way."

@Chrispydoc and others have more experience in jump starting so I am sure they will correct us if if we are both wrong.

"I'm not wrong "

 

[KasEV]

@Mgkev,
The circuits in a PHV are different from that of a BEV so one should never say because this or that happens with a PHV it will also by all means happen with a BEV.
So far as jump starting is concern I think there is now a consensus.
@MG Technician says it can be done. So one may accept that as coming from someone in the know.
Others, myself included say that is not prudent and is not what we have read, heard or seen as the most appropriate way to deal with a flat battery in a BEV.
So some say if 12VB is flat, check the status of your HBV. If your HBV is also flat or even if it is not, charge you car in the normal way and reassess. If after charging only the 12VB remains flat then call AA/MG or replace the battery and avoid jump start. However jump start if you deem that prudent and appropriate.
Indeed no one is prohibiting you from jump starting if you deem that is the best approach. All we are saying is if Jump Start is what you want to do then make sure your HBV is adequately charged.
So I think this jump start issue has been adequately resolved.
I know you may just want a better understanding of why some are saying you should not jump start a BEV at all but I worry further discussions may breed more confusion on this issue.
I think a consensus as I have indicated above is a good place to stop.

 

[Mark Holmes]

@Mgkev,
The circuits in a PHV are different from that of a BEV so one should never say because this or that happens with a PHV it will also by all means happen with a BEV.
So far as jump starting is concern I think there is now a consensus.
@MG Technician says it can be done. So one may accept that as coming from someone in the know.
Others, myself included say that is not prudent and is not what we have read, heard or seen as the most appropriate way to deal with a flat battery in a BEV.
So some say if 12VB is flat, check the status of your HBV. If your HBV is also flat or even if it is not, charge you car in the normal way and reassess. If after charging only the 12VB remains flat then call AA/MG or replace the battery and avoid jump start. However jump start if you deem that prudent and appropriate.
Indeed no one is prohibiting you from jump starting if you deem that is the best approach. All we are saying is if Jump Start is what you want to do then make sure your HBV is adequately charged.
So I think this jump start issue has been adequately resolved.
I know you may just want a better understanding of why some are saying you should not jump start a BEV at all but I worry further discussions may breed more confusion on this issue.
I think a consensus as I have indicated above is a good place to stop.

It also tell you how to do it in the owners manuals.

 

[KasEV]

@Mark Holmes,
We really should just stop discussing this issue as we have reached a sensible consensus. You know we have already quoted the manual and explained that this is a copy and paste from the ICE manual. Just like the section in the manual which says avoid the hot exhaust when the ZS EV like any BEV has no exhaust.
Anyway there is no argument, jump start if you think it is prudent and for those of us who believe our understanding of BEV power curciuts makes it not prudent to jump start we will avoid jump starting.

 

[MG Technician]

I never said the EV

It also tell you how to do it in the owners manuals.

can be jump started

@Mgkev,
The circuits in a PHV are different from that of a BEV so one should never say because this or that happens with a PHV it will also by all means happen with a BEV.
So far as jump starting is concern I think there is now a consensus.
@MG Technician says it can be done. So one may accept that as coming from someone in the know.
Others, myself included say that is not prudent and is not what we have read, heard or seen as the most appropriate way to deal with a flat battery in a BEV.
So some say if 12VB is flat, check the status of your HBV. If your HBV is also flat or even if it is not, charge you car in the normal way and reassess. If after charging only the 12VB remains flat then call AA/MG or replace the battery and avoid jump start. However jump start if you deem that prudent and appropriate.
Indeed no one is prohibiting you from jump starting if you deem that is the best approach. All we are saying is if Jump Start is what you want to do then make sure your HBV is adequately charged.
So I think this jump start issue has been adequately resolved.
I know you may just want a better understanding of why some are saying you should not jump start a BEV at all but I worry further discussions may breed more confusion on this issue.
I think a consensus as I have indicated above is a good place to stop.

I have never said the EV can be jump started Kas. There's no such thing as being able to jump start a full electric vehicle. Please don't put words in my mouth.

 

[KasEV]

Its fine to put a 12volt power pack on the 12v battery or jumper cables from another vehicle thats not running if your 12v battery is flat.

@MG Technician,
I note your comments.
Not sure exactly what your post from 9th July means. I am sorry if I wrongly interpreted it as you saying one can jump start a BEV.

 

[MG Technician]

@MG Technician,
I note your comments.
Not sure exactly what your post from 9th July means. I am sorry if I wrongly interpreted it as you saying one can jump start a BEV.

Hi, KasEV
Not a problem, I do forget that it's hard for some people who are not technically minded to understand what I am saying. I will try harder to be clearer with my comments in the future.

 

[Harry]

@Kithmo,
Yes I have seen this. In the opinion of most EV boffins this is a nonsense and a result of MG's lazy cut and paste approach from the ICE manual.
It says....
View attachment 332
Just imagine your 12BV and your HBV are both flat.
No amount of Emergency starting with jump leads will get you anywhere in such a situation.
What should have happened here is that they should have differentiated between HBV being flat and 12BV being flat while has HBV has adequate charge.
Now since most EV observers think that flat 12BV with adequate charge HBV situation should not occur in normal use they also tend to disagree that the approach to resolving it when it occurs is simply to jump start.
The general EV advice is that in normal use (ie regular drive and top up charge) flat 12VB with adequate HBV charge should not occur. If it occurs get your vehicle checked.
If is occurs anyway then charging the EV to ensure the 12VB also recharges is one recommended option.
The jump start option is not advised by most. That is all one can say for sure on this issue.

This reviewer used jump starting successfully on Kia e-Niro.

 

[Elec Car Aust]

@ARvanHAS,
I agree with your comment on NOT jump starting EVs.
All the information I have to date indicate no need to charge the 12VB if one charges the HVB regularly.
I have not come across information stating directly that do not jump start the 12VB on an EV. Hence I put the question to my EV Boffins. They laughed their heads off and just said the situation where the 12VB was dead but the HVB had adequate charge is not meant ever to happen in normal everyday EV usage. The only time it may occur is storage for more than 2-3 month. Solution for that situation for ZS EV is to remove the connection leads to the negative pole of the 12VB during the storage period then reconnect and charge the car as normal after storage period before using the car. In the opinion of my boffins, when the situation occurs in normal use that the HVB is OK but 12VB is dead then there is something seriously wrong with the circuits in the car and the solution is not jump starting.

Hi, we have heard numerous stories where dashcams (on constant standby) have flattened the 12 volt battery in as little as 4 days while parked at airport, so it does happen. EV won't start with dead 12 volt so need jump start to energise the systems and start car.

EV mechanics here say EV 12 volt is no different to ICE as long as normal procedure and safety are observed. We have jump started a few EVs using a hand help starter with no problems. This video shows the starter we carry in the boot, haven't needed ourselves but helped out other stranded EV owners as mentioned.

 

[Dubber]

We have a HG5 - We have a similar problem with the HV battery disconnect coming up when you get in the car, depress the brake and the start button. If you don’t here the whizz of start up the warning comes up and the car will not start. You can try several times without success and end up goi g I doors to wait 15 mins or so. It’s caused us to miss trains - be late picking up grandchildren etc. - sometimes the warning comes on as you are driving. The car is usually kept at 70-100 per
Cent charged.

 

[Dubber]

Any ideas as the dealer hasn’t a clue?

 

[lusitano]

Any ideas as the dealer hasn’t a clue?

To me this was the 12v battery that was drained and wouldn't charge or hold charge.

 

[Dubber]

To me this was the 12v battery that was drained and wouldn't charge or hold charge.

Dealer said they checked the battery and it was fine

 

[Kithmo]

If the battery is sound then it must be a faulty HV battery isolator relay.

 

[Jdejong1981]

There is a update for the DAB system. When the car is switched off , the infotainment system still keep searching for DAB stations.
Therefore the system (12v) will get drained.

Last week during the first service they updated the DAB system.

Greetings Joost

 

[scoobeesnac]

I have been monitoring our Mk2 and hoping to see the HV charge the 12v automagically at some point but nothing showing yet. Will have to leave the car for more than a couple of days to see what happens.

 

[ARW]

Andrew,

Just as a matter of interest why do you want to press the start button twice with your foot off the brake pedal?

Frank

It is the same as turning the key but not starting the car allows all the accessories to come on without running the engine