MG ZS 12V battery SoH

[Required]

So yesterday my MG5 got carted off to the dealership on the back of an AA van for what appears to be a fault with the charging of the 12V battery.

My 21 plate ZS has the 12V battery gauge on dash and that's currently showing just over half full - what are people's experiences with this gauge and is it worth replacing this 12V battery early just to be on the safe side? I'm now slightly paranoid about having two knackered cars as a result of 12V battery issues!

 

[fatboyfat1981]

You’re not the only person to have had issues- the OEM 12V appears to be made from the finest Chinesium, not helped by the cars sitting for long periods while awaiting shipping from China.

I’m 16 months in on a Mk2 ZS and haven’t had any problems, however as the 12V is charged from the HV Battery and I use Moby a lot, it hasn’t been a problem (yet).

 

[MG steve]

Invest in a battery power pack jump starter.

 

[Required]

Yeah, I think there'll be one each on the way!

 

[JCFlippen]

At the first hint of trouble with my TCLR I will fit a proper Bosch battery that has a decent warranty.

 

[Required]

I'm going to Google TCLR and then probably agree with you!

 

[Gadget Geek]

I'm going to Google TCLR and then probably agree with you!

Trophy Connect Long Range.

 

[Wobbly]

Yeah, I've had to be rescued by the AA because of a flat 12V battery!
That was 18 months ago.
I invested in a booster pack but of course I've had no issues since!
We shouldn't have to worry about a 12V battery in a £30 k car!!

 

[TassieDi]

Fitting a 12V battery monitor is also a good idea. Then you'll really see how the 12V battery is behaving, and can be forewarned if there are any issues building up.

 

[Required]

I'm more annoyed that the bit of the EV which has failed is the bit they took from none EVs!

Update though - swapping the 12V battery has done sod all in terms of bringing the MG5 back to life so no idea what's going on. The dealer is obviously closed for Mon/Tue at a minimum so it'll be the 27th at the absolute earliest before we hear anything further.

 

[MG steve]

Yeah, I've had to be rescued by the AA because of a flat 12v battery!
That was 18 months ago.
I invested in a booster pack but of course I've had no issues since!
We shouldn't have to worry about a 12v battery in a £30 k car!!

Yeah but if you hadn’t purchased a booster you’d have needed it!

 

[andymgzs]

So yesterday my MG5 got carted off to the dealership on the back of an AA van for what appears to be a fault with the charging of the 12v battery.

My 21 plate ZS has the 12v battery gauge on dash and that's currently showing just over half full - what are people's experiences with this gauge and is it worth replacing this 12v battery early just to be on the safe side? I'm now slightly paranoid about having two knackered cars as a result of 12v battery issues!

My ZSEV 2020 has had many 12V battery failures (goes flat for absolutely no reason) - one time as mad as waiting in a drive through - 12V goes flat then have to be towed out. Other time parked up for 1 hour, other times at an airport for a few days.
Another issue that MG refuse to accept. They plug in the diagnostic and computer says it’s Ok. I think this is a MG default to avoid any warranty issues.
AA should write a review because they know all of the issues.

 

[Coulomb]

My ZSEV 2020 has had many 12v battery failures (goes flat for absolutely no reason)

That sounds like a faulty DC-DC. Does the auxiliary battery voltage reach 14V when in ready mode?

 

[andymgzs]

I’m always impressed with this forum because there is a huge amount of experience and advice out there.

Answer is that I don’t know. I’ll look next time. And will ask MG to look at this.

It’s a complete pain in the ass when it happens because it immobilises the car and cannot get into it. Dash board is completely dead when it happens.

Just 337 days of the lease left then it goes.

 

[Spinynorman]

I have a 2020 ( Mk 1 as I call it) and have had a lot of warnings about low 12V when I start up the car. I don’t do a lot of mileage now, as I bought the car just as Lockdown started and now work from home permanently, so lucky if it gets a drive once a week!.
but recently, after doing a full home charge/equalisation to 100% and leaving the charger plugged in overnight after my Zappi had completed the charge, I haven’t seen any problem with it.
I’m thinking though I’ll put it on a battery maintainer, as this did the job for my old (I had it 28 years!) ICE Toyota RAV4.
My only problem is that as I have a free CPZ permit for the car, I don’t park it up in my driveway. Here in deepest darkest East London, we have a problem with burglaries, where they only break in for the car keys of the car in the drive - though quite selective, in it only seems to be high Mark (I.e. BMW/Merc/Range Rovers etc) cars that they target.
So parking my car in a nearby bay means they can’t remote capture my key signal (I have it in a Faraday pouch and biscuit tin) as the crims don’t know what house to scan but I have to park up to charge, so it means putting on a 24/7 maintainer would mean parking the car in the drive and risking an unauthorised visit!
I think I’ll take the risk and tidy up my ‘seemingly unused’ driveway…

 

[Zoomy]

The 12V gauge shows voltage, not state of charge.

 

[Aidanw]

I’m 16 months in on a Mk2 ZS and haven’t had any problems, however as the 12v is charged from the HV Battery and I use Moby a lot, it hasn’t been a problem (yet).

I just wanted to give props for the naming. Ours is called M?ggy, with the teen requiring it to be spelled using an emoji for the "o".