Dead 12 volt battery

[KasEV]

Folks,
I am with @Frank on this issue.
Yes, I agree with all of you that where necessary precautions should be taken so I have nothing against having a jumpstarter. But I personally will not deem a 12VB jumpstarter a very necessary precaution for a modern EV. l will save the money for something else.
Far easier and straightforward to plug in overnight or charge at least once a week. If you are doing that and yet getting a flat 12VB then there is something wrong with your electrics and a jumpstarter is not the solution. You need your electrics checked.
Modern EVs are wired to ensure flat 12VB does not occur when the EV is in use even if use is infrequent to a total of I hour driving a week. The manufacturer has otherwise given advice on what to do when the EV will not be used for a long time. That is to disarm the negative pole of the 12VB until you are ready to use it. When you are ready to use the ZS EV you reconnect the 12VB negative pole and charge the car and off you go.
I think we often just complicate things for ourselves when just following the simple manufacturers instructions is better.

 

[Jeps]

Folks,
I am with @Frank on this issue.
Yes, I agree with all of you that where necessary precautions should be taken so I have nothing against having a jumpstarter. But I personally will not deem a 12VB jumpstarter a very necessary precaution for a modern EV. l will save the money for something else.
Far easier and straightforward to plug in overnight or charge at least once a week. If you are doing that and yet getting a flat 12VB then there is something wrong with your electrics and a jumpstarter is not the solution. You need your electrics checked.
Modern EVs are wired to ensure flat 12VB does not occur when the EV is in use even if use is infrequent to a total of I hour driving a week. The manufacturer has otherwise given advice on what to do when the EV will not be used for a long time. That is to disarm the negative pole of the 12VB until you are ready to use it. When you are ready to use the ZS EV you reconnect the 12VB negative pole and charge the car and off you go.
I think we often just complicate things for ourselves when just following the simple manufacturers instructions is better.

I agree on that. A jumpstarter is not anecessaryty to have in a electric car.
It seems like the infotainment system in my car is having some gremlins, and MG Denmark will look into that. We haven't ruled out that there also could be a problem with the 12 v battery itself. So the comming days I will monitor what is happening.

 

[CDR]

Folks,
I am with @Frank on this issue.
Yes, I agree with all of you that where necessary precautions should be taken so I have nothing against having a jumpstarter. But I personally will not deem a 12VB jumpstarter a very necessary precaution for a modern EV. l will save the money for something else.
Far easier and straightforward to plug in overnight or charge at least once a week. If you are doing that and yet getting a flat 12VB then there is something wrong with your electrics and a jumpstarter is not the solution. You need your electrics checked.
Modern EVs are wired to ensure flat 12VB does not occur when the EV is in use even if use is infrequent to a total of I hour driving a week. The manufacturer has otherwise given advice on what to do when the EV will not be used for a long time. That is to disarm the negative pole of the 12VB until you are ready to use it. When you are ready to use the ZS EV you reconnect the 12VB negative pole and charge the car and off you go.
I think we often just complicate things for ourselves when just following the simple manufacturers instructions is better.

Modern ev or not, the fact is that this happens all to regularly and I for one was stuck twice in the ZS and more than 5 times in my previous ev which was an ioniq bev, waiting for the AA to call out and all he did was jump the contactor too. On one occasion the 12v battery was replaced under warranty, another time my boot didnt close properly, another time the battery terminal came loose on one of the terminals and the 12v died. I think there is no harm having a booster especially if you don't have time to wait for help. Obviously if it happens all the time one would need to get it checked, that goes with out saying, but this is a forum to share personal experiences which will help some folks to understand an issue they may be having.

 

[Redpiratepete]

Hi All,
I had thìs problem after a couple of days not using the car, I received the message HV battery not connected!
It still happens today, but the AA technical dept rang me before sending an engineer and told me the following:-
1. Use the key fob button to lock and unlock the doors.
2. Foot on the brake pedal.
3. Apply the throttle pedal at the same time. (A technic used by competition drivers called "toe and heel")
4. Then press the start button.
This works every time so far.
I have complained to MG and requested a new larger size battery, but of course the robbed me off.
I used the wall box to charge the car the first time it happened, The second time this didn't work, so I jump started it, The 3rd time I called the AA (warranty).
This was Dec / Jan time and the technic above has been fine since.
As a group we should get on to MG so this COMMON problem could be rectified.
Redpiratepete

 

[Jeps]

Hi All,
I had thìs problem after a couple of days not using the car, I received the message HV battery not connected!
It still happens today, but the AA technical dept rang me before sending an engineer and told me the following:-
1. Use the key fob button to lock and unlock the doors.
2. Foot on the brake pedal.
3. Apply the throttle pedal at the same time. (A technic used by competition drivers called "toe and heel")
4. Then press the start button.
This works every time so far.
I have complained to MG and requested a new larger size battery, but of course the robbed me off.
I used the wall box to charge the car the first time it happened, The second time this didn't work, so I jump started it, The 3rd time I called the AA (warranty).
This was Dec / Jan time and the technic above has been fine since.
As a group we should get on to MG so this COMMON problem could be rectified.
Redpiratepete

Why that technic you mention? If the battery is low I can't see it could help!

 

[Redpiratepete]

Hello Jeps
The AA tech rep suggested that using the key fob initalises the cars "systems" , which the handle button doesn't.
The 12v battery isn't nessecarly flat, just down on volts, even 0.5 of a volt may be enough to prevent starting. If you check the 12v battery gùage, when the car says no HV battery connected, mine shows bars exactly on the half way mark, but when running normally it's always 2 divisions past towards "full"!
Redpiratepete

 

[Jeps]

Hello Jeps
The AA tech rep suggested that using the key fob initalises the cars "systems" , which the handle button doesn't.
The 12v battery isn't nessecarly flat, just down on volts, even 0.5 of a volt may be enough to prevent starting. If you check the 12v battery gùage, when the car says no HV battery connected, mine shows bars exactly on the half way mark, but when running normally it's always 2 divisions past towards "full"!
Redpiratepete

Hi Redpiratepete.
My Battery went down to only 2.85 v after not being used for 5 days.
When I drive, my gauge also show 2 bars beyond half full.
I had a talk with my MG dealer 2 days after the insident, he called me for an update on the car?. So far I will monitor the car for any weird behaviours, and if anything happens I bring it in. The guy from MG told me that the car doesn't charge the 12 v battery while charging the main HV battery. So he didn't suspect it to be 12v battery related problem.
So far after a week, there hasn't been any problems to report?

 

[GordieG]

I had the same issue during the first week with my new ZS - sometimes switching off and on several times and still getting the ‘HV Battery not connected‘ message - but by locking the car and starting again it usually worked. After a few days of frustration I realised that I had got into the habit of ICE start-up and needed to change the routine for EV. In an ICE vehicle it is common practice to press the start button with no foot pedal before you’re ready to engage gear and drive off, if you do that in the EV (to check instruments, radio, phone, whatever) you are only using the 12v battery and the HV is not connected. Every time I get into the car now, I fully depress the brake pedal and press the start button. Hey Presto! Never had the problem since!

 

[Mgkev]

Can I just ask, does the MG charge the 12v battery when DC charging with the car switched “on”?

 

[Frank]

Hi All,
I had thìs problem after a couple of days not using the car, I received the message HV battery not connected!
It still happens today, but the AA technical dept rang me before sending an engineer and told me the following:-
1. Use the key fob button to lock and unlock the doors.
2. Foot on the brake pedal.
3. Apply the throttle pedal at the same time. (A technic used by competition drivers called "toe and heel")
4. Then press the start button.
This works every time so far.
I have complained to MG and requested a new larger size battery, but of course the robbed me off.
I used the wall box to charge the car the first time it happened, The second time this didn't work, so I jump started it, The 3rd time I called the AA (warranty).
This was Dec / Jan time and the technic above has been fine since.
As a group we should get on to MG so this COMMON problem could be rectified.
Redpiratepete

Hi,

I agree with all the above except for number 3, what a load of bloody nonsense they are telling you. First of all you do not have have an ICE car so you can't apply ICE practices to it. However as a driver of many many years (and I hope I am not teaching you to suck eggs) "toe and heel" is a practice that all drivers can use when braking and blipping the throttle to change down gears without locking the wheels. This was an important method when gearboxes did not have synchromesh in all its gears. Younger drivers won't have a clue when you mention doubling the clutch when changing gears which was a necessity with non synchromesh gearboxes. "toe and heel" has no relevance whatsoever with the MG ZS EV or ANY other EV and he or her is talking a lot of tosh, completely ignore it.

I will say it again, if you have a home charger, charge your car EVERY NIGHT when you are finished with it, and if you still have problems with the 12V battery then there is a FAULT.



Regards

Frank

 

[Kithmo]

Hi,

I agree with all the above except for number 3, what a load of bloody nonsense they are telling you. First of all you do not have have an ICE car so you can't apply ICE practices to it. However as a driver of many many years (and I hope I am not teaching you to suck eggs) "toe and heel" is a practice that all drivers can use when braking and blipping the throttle to change down gears without locking the wheels. This was an important method when gearboxes did not have synchromesh in all its gears. Younger drivers won't have a clue when you mention doubling the clutch when changing gears which was a necessity with non synchromesh gearboxes. "toe and heel" has no relevance whatsoever with the MG ZS EV or ANY other EV and he or her is talking a lot of tosh, completely ignore it.

I will say it again, if you have a home charger, charge your car EVERY NIGHT when you are finished with it, and if you still have problems with the 12V battery then there is a FAULT.



Regards

Frank

I'm glad I'm not the only one who thought number 3 was nonsense. I thought it might be some sort of magic trick pertaining only to the MG ZS EV.
I know in my Prius, if you press the brake pedal it automatically kills the signal to the accelerator, so there's no effect whatsoever from the accelerator pedal.

 

[lee graham]

3. Bang fuel pump with your shoe.

 

[Noraf142]

Even on my Panda, if I touch the brakes, the car kills the throttle.
Good tips for newbies here, thanks a lot folks

 

[KasEV]

Hi All,
I had thìs problem after a couple of days not using the car, I received the message HV battery not connected!
It still happens today, but the AA technical dept rang me before sending an engineer and told me the following:-
1. Use the key fob button to lock and unlock the doors.
2. Foot on the brake pedal.
3. Apply the throttle pedal at the same time. (A technic used by competition drivers called "toe and heel")
4. Then press the start button.
This works every time so far.
I have complained to MG and requested a new larger size battery, but of course the robbed me off.
I used the wall box to charge the car the first time it happened, The second time this didn't work, so I jump started it, The 3rd time I called the AA (warranty).
This was Dec / Jan time and the technic above has been fine since.
As a group we should get on to MG so this COMMON problem could be rectified.
Redpiratepete

@Redpiratepete
Sorry to hear of your issues with the car.
Anyway I think you are having an electrical circuit problem and the answer to the problem is definitely not toe to heel or jump starting. You need a proper check of your power circuits.
I am a bit confused as to why you think your issue has anything to do with your 12VB.
If the message is "HVB not connected" then there is no chance on earth anything will work except reconnection of the HBV. None of the things you did which appear to resolve your issue are ways of reconnecting the HBV. If it keeps happening then have it checked. Either you are getting a false alarm of your power circuits are malfunctioning.
Also the HBV is totally different from the 12VB and I thought the trend has been about the issues some are having with their 12BVs.
The issues that have been raised about 12VB so far in my opinion are due to misunderstanding and misinformation rather than reality of the way EVs function.
Please no one should take offence.!!!! Just my humble opinion.
There are thousands of EV users and reviewers and so far as I am aware non of the issues in this trend has ever been highlighted as a recurrent and persistent issue in the ZS EV or other EVs.

 

[Mgkev]

I have this problem with my Prius. If the boot light switch is left in the AUTOMATIC position the 12v battery goes flat. The light does not erroneously stay on and the car was ex-demo and delivered with the switch in the OFF position so I suspect the fault was known to the previous driver.

 

[Coedy]

I have this problem with my Prius. If the boot light switch is left in the AUTOMATIC position the 12v battery goes flat. The light does not erroneously stay on and the car was ex-demo and delivered with the switch in the OFF position so I suspect the fault was known to the previous driver.

Also have a Prius, also have had a dead 12v thanks to the bit light, also leave it in the OFF position now ?

 

[Kithmo]

I switched my Prius boot light switch off when I got it due to hearing about it on the forums.
I notice the MG doesn't have a switch on the boot light, so must remember to make sure the boot is shut tight.

 

[Mgkev]

Well there you go, I never realised that the boot light was a known issue.

 

[KasEV]

Very interesting, I use to have a Ford with faulty in-car lights and the result was that my batteries run flat very often.
When I got feed up I went and got it fixed.
There were other guys in my circle of friends, coworkers and colleagues with same problem they had BMW, Audi, Mercedes and VOLVO.
Guess what we never came to the conclusion that these brands had something wrong with them. We knew that the fault was with our individual cars. Also we did not think all cars have a problem. These were all ICE in the good old days. I wonder if we should have concluded that there was something wrong with all ICE.
Well folks what do you think??????....
For me the practical thing is that if I do manage the ZS EV as recommended in the owners manual and charge my car as recommended then I am 100% sure I am extremely unlikely to have a flat 12VB and I do not spend a second thinking about that. If I get a flat 12VB it will be most likely my fault. Maybe I left the lights on or did something else foolish or even something stupid on my part and nothing to do with EVs as such.
This is my humble opinion.
I will not be recommending "toe to heel" or "jump starts" to anyone and although I am not a professor of EV's, I know enough to question the validity and veracity of any suggestion on this forum. I hope I am allowed to express my humble opinion even if I am wrong. When I am wrong, I am very happy to admit I am wrong when I am corrected with valid facts.
So far in my opinion I am not seeing valid facts in this discussion.
My advice to all is to follow the very practical and sensible advice given by @Frank and others in this discussion.

 

[auris]

I leave mine in the car all the time plugged in to the usb port. That way it is always trickle charging and will be full if I need it. The usb ports power supply is cut off when the car is switched off, so no need to worry about draining the 12v by leave the booster plugged in all the time.
Its like having a bit of security.

Sorry, missing something here - what do you leave plugged in the USB port - a powerbank? And is so, how does that help if the battery is completely flat, as you mentioned - USB is turned off when the car is shut/locked, so unless it's force unlocked, and a jump start connected on the 12v battery, run mode/acc turned on USB would not be activated, by when you may already be charging the car from the main battery? What am I missing?