MG4 Low voltage battery chasing system fault

[tsedge]

If you could drive the car back to the dealers (admittedly I am assuming) and the 12v battery was at 8v then either the 12v battery is kaput or the dc/dc converter is faulty. Did they initially tighten the battery connectors or replace the 12v battery because once below about 10 - 12v for any period the battery will degenerate quickly and fail?

Is there any reason why we can't charge or change the 12v battery ourselves (are they special in some way?)

 

[Ian Key]

It's a standard car battery so I can't see why not.

 

[the briggie]

You can jump lead/charge/change them no problem. I recommend that any replacement battery is the same specification to avoid any potential issues. With a car within such a short period of ownership I would expect them to attempt to diagnose what caused the drain and if dodgy provide a replacement. Most are supplied with a 2/3 year guarantee. Some settings may change when disconnecting/reconnecting a battery so be aware.

 

[tsedge]

You can jump lead/charge/change them no problem. I recommend that any replacement battery is the same specification to avoid any potential issues. With a car within such a short period of ownership I would expect them to attempt to diagnose what caused the drain and if dodgy provide a replacement. Most are supplied with a 2/3 year guarantee. Some settings may change when disconnecting/reconnecting a battery so be aware.

I wonder if the specification is part of the problem? A few makes have struggled with 12V batteries. Early Teslas failed a lot.

I would have thought a higher spec would be safe but I suppose we don't know how it charges and it might be calibrated for a certain capacity.

 

[the briggie]

I replaced one on my kia e-niro with a better battery than the manufacturer supplied battery after 2 years. There was known issues with the kia one and I put a Varta in with a slightly higher amperage but not excessive (recommended on kia forum). I don't know how good the MG4 one is......

 

[tsedge]

I've had ICE batteries die between 5-7 years age on quite a few cars now. Do you think EVs need more regular replacement?

 

[the briggie]

I've had ICE batteries die between 5-7 years age on quite a few cars now. Do you think EVs need more regular replacement?

There should be no reason that they should not last the same but are manufacturers saving money by installing lower quality batteries...who knows. If the12v goes low the car is a brick. I honestly think that because a shove/tow is out the equation it elevates the issue in some peoples minds. I bought this NOCO Boost Sport GB20 500A 12V Portable Lithium Jump Starter - Black B+ as a just in case option.

 

[PeteC]

I've had ICE batteries die between 5-7 years age on quite a few cars now. Do you think EVs need more regular replacement?

The one in my 8 year old BMW i3 was still fine when I sold it. I sometimes left that car for over a month while visiting family abroad and never had any problems.

 

[Lovemyev]

I bought this NOCO Boost Sport GB20 500A 12V Portable Lithium Jump Starter - Black B+ as a just in case

After reading about a few ZS EV Gen1 members getting caught out with low SOC in their 12 volt batteries, when they where using their radio etc, with the car was in “STANDBY” mode and not “READY” mode.
So, two years ago I decided it would be a good idea / back up plan, to purchase a 12 volt jumper / booster pack.
It lives under the drivers seat, just in case of a low SOC in the battery.
It has now been transferred over to our ZS EV LR.
Strangely enough, in the last three years it has been used more than enough times to boost OTHER people’s cars !.
It’s one of them really, you buy one and it sit’s unused for months and months on end, but then one day completely out of the blue, with out warning, it’s services are suddenly called upon !.
Then the cost outlay is 100% worth it.
It’s about as close as you can get, to carrying a spare 12 volt battery around with you !.