MG4 Dead !!

[Ian Key]

Lifted my bonnet today to see how much rubbish can accumulate above the undertray following seeing how bad a Tesla was on FB when they took the frunk out (looked like a forest floor)

My negative battery terminal was virtually off and a slack as a....

Had to get the spanners out push it down and nip it up

Which could be why some have had a flat 12v battery or appear to have one.
Another item on the check list ?

 

[DevonMG4]

Lifted my bonnet today to see how much rubbish can accumulate above the undertray following seeing how bad a Tesla was on FB when they took the frunk out (looked like a forest floor)

My negative battery terminal was virtually off and a slack as a....

Had to get the spanners out push it down and nip it up

Has it been to a dealer for repair where they may have removed it or is it loose from the factory do you think?

 

[Ayoull]

Has it been to a dealer for repair where they may have removed it or is it loose from the factory do you think?

Only mechanical repair it's had is oil breather and I had my non-existant rear undertray fitted can't see either of those involving the battery

 

[Lovemyev]

A 12 volt battery booster pack a 10mm spanner and a Type 2 public charging cable is regarded as "Standard Equipment" for EV owners, I personally think.
All could help you out of a sticky situation and a long wait from the recovery people.

 

[avhation]

On p291 of the manual in relation to the battery, it says, “
Note: It is recommended to set the power mode to READY for more than half an hour every week to help extend the service life of the battery. When the vehicle will not be used for an extended period (more than 1 month), it is recommended to disconnect the battery negative terminal clamping pile head. Make sure that the vehicle power system has been turned off before connecting or disconnecting the negative battery cable.”

Having disconnected the 12v battery can one lock the car and unlock on return from holiday etc? Perhaps with physical key? Presume that alarm or immobiliser would not protect car from theft - would insurer be content I wonder?

 

[Lovemyev]

Having disconnected the 12v battery can one lock the car and unlock on return from holiday etc? Perhaps with physical key? Presume that alarm or immobiliser would not protect car from theft - would insurer be content I wonder?

If you disconnect the 12 volt supply, you will have to lock / unlock the car with the emergency key.
Your alarm will not be functional either of course.
What about purchasing a 12 volt booster pack as a back up plan ?.

 

[avhation]

Dont forget li-ion batteries cant be charged if they are below 0, so now you have to insulate it too

Also a lead-acid charger is unsuitable for a lithium battery.

If you disconnect the 12 volt supply, you will have to lock / unlock the car with the emergency key.
Your alarm will not be functional either of course.
What about purchasing a 12 volt booster pack as a back up plan ?.

I have a redundant 12v 18ah golf trolley battery. Might stow it in the boot with low current cable and crocodile clips and top up on the hopefully infrequent occasions I charge the main battery (LR).

 

[Lovemyev]

I have a redundant 12v 18ah golf trolley battery. Might stow it in the boot with low current cable and crocodile clips and top up on the hopefully infrequent occasions I charge the main battery (LR).

Just a thought, will this golf cart battery be sufficiently powerful enough to bring up the SOC of 12 volt battery the car, on the off chance that it has discharged to a really low level on your return ?.
I recommend a purpose built booster pack with plenty of redundancy !.

 

[troopercooper]

A 12 volt battery booster pack a 10mm spanner and a Type 2 public charging cable is regarded as "Standard Equipment" for EV owners, I personally think.
All could help you out of a sticky situation and a long wait from the recovery people.

Can confirm! I bought a £60 one from Halfords on a whim and on Christmas Eve night after stalling at some lights, our battery couldn’t turn over the starter motor. Pushed it to the side of the road, hooked it up and the little engine came back to life. Best £60 I ever spent, highly recommend always keeping one handy.

 

[Lovemyev]

Can confirm! I bought a £60 one from Halfords on a whim and on Christmas Eve night after stalling at some lights, our battery couldn’t turn over the starter motor. Pushed it to the side of the road, hooked it up and the little engine came back to life. Best £60 I ever spent, highly recommend always keeping one handy.

Used on a ICE but clearly displays the advantages of having a booster pack on hand !.
A really useful addition to protect youself.
I have a booster pack in our ZS EV face lift and my wife's Fiat 500.
They have been used more to help other people stranded than ourselves, but I am pleased about that.
If my car or my wife's car never needs its use, I am a happy bunny.
But it's there if we / other people need it !.

 

[avhation]

Just a thought, will this golf cart battery be sufficiently powerful enough to bring up the SOC of 12 volt battery the car, on the off chance that it has discharged to a really low level on your return ?.
I recommend a purpose built booster pack with plenty of redundancy !.

Thanks, I agree. I 'll build up some knowledge of the 12v state of charge over a period of time to gain confidence that I can trust the battery not to become below 12v or so off load.

 

[Lovemyev]

Thanks, I agree. I 'll build up some knowledge of the 12v state of charge over a period of time to gain confidence that I can trust the battery not to become below 12v or so off load.

Agreed, but what if you arrive home from your holiday and your 12 volt battery is too low to start the car, I strongly suggest purchasing a booster pack.
If you buy one, you will never need it, but if you don't you will !.
Thanks how it goes .

 

[Chr1sB]

All this talk of 12v booster packs - what does one look for to ensure that it can bring back a 12v from 3v charge and bring the car to life ? I mention 3v as that how low my 12v had got and the AA man tried a booster pack and then had to resort to jump leads from his van to get it to start.

Just by way of an update - MG have never got to the bottom of why my battery went flat albeit loads of software updates applied yesterday - incl Shut In fix - as they hadn’t been applied at PDI !! (11 weeks ago)

 

[Cocijo]

All the booster needs to do is provide sufficient energy to enable the HV pack to be tripped and engaged. A good pack will have a boost function and should be able to do this without charging the 12v. After the HV is engaged it will charge the 12v. You don’t use the booster to charge the 12v.

 

[Lovemyev]

Some of the smaller size booster packs are fine, if the SOC of battery has only a little low.
But if the SOC has dropped extremely low, then a small booster pack is not going to have the capacity to raise the battery to a sufficient level.
The pack I use is a medium size pack that has enough capacity to start a large fossil engine, multiple times.
I used it a few weeks ago to help a neighbour who had returned from a trip and found he had left his side lights on !.
The 12 volt battery must have been super low.
I connected my booster pack and pressed the “Boost” button.
The button turns green, when the back has absorbed enough juice to attempt a jump start.
The pack was connected for about 3 minutes before the green light came on, giving some indication of how flat my neighbours battery really was.
I don’t think a smaller booster would done the same job.

 

[Chr1sB]

Something like this ? ... or should I look for a higher 'peak' output ?

Amazon product ASIN B0BLNJWV6X

 

[Cocijo]

Some of the smaller size booster packs are fine, if the SOC of battery has only a little low.
But if the SOC has dropped extremely low, then a small booster pack is not going to have the capacity to raise the battery to a sufficient level.
The pack I use is a medium size pack that has enough capacity to start a large fossil engine, multiple times.
I used it a few weeks ago to help a neighbour who had returned from a trip and found he had left his side lights on !.
The 12 volt battery must have been super low.
I connected my booster pack and pressed the “Boost” button.
The button turns green, when the back has absorbed enough juice to attempt a jump start.
The pack was connected for about 3 minutes before the green light came on, giving some indication of how flat my neighbours battery really was.
I don’t think a smaller booster would done the same job.

Sometimes it can be better to disconnect the 12v if it’s really low and connect the booster direct.

 

[Cocijo]

Something like this ? ... or should I look for a higher 'peak' output ?

Amazon product ASIN B0BLNJWV6X

I got that one - a while ago though and they’ve gone up considerably! Try shopping around - eBay is sometimes cheaper on these type of products.

 

[wandle MG4 trophy]

Just bought a Halfords own label Jump Starter kit for £60 (less 5 or 10% if you join their discount scheme). A larger capacity version is also available. The instructions say it will not work if the 12v battery has dropped to 3v or below.
Given that the battery in an EV does not need to crank a starter motor, I hope mine which is rated for a 2 litre ICE will do the trick.
It’s about the size of a very large smart phone (cables are separate) so should fit in the glove box. It does not come with a carry case. It needs to be recharged every 6 months.
Fingers crosSED I never need to use it

 

[Cocijo]

Yep - keep in the passenger compartment somewhere - if it’s in the boot you might have to scrabble and struggle to get to it…