12 volt battery

Phil Hayward said:
My 12v battery went flat a few times when new, never found the reason, starting behaving by the time I had read the instructions.
I made a short video of me checking the 12v charger with a volt meter in the cigar lighter.

I have a new Bosch battery, I will change it at sometime, Bosch silver line lasted 15 years on my Vectra.
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Hi, does anyone know if you can change the 12V SAIC branded battery yourself on the MG ZS pre-facelift? Did you change yours Phil? There some comments that battery changes need to be registered with the car's onboard computer/battery management on the general internet so it's not clear if it's a DIY job any longer. My battery hasn't died yet, I was thinking of using it for a project at home.
 
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Ealing Guy said:
Hi, does anyone know if you can change the 12V SAIC branded battery yourself on the MG ZS pre-facelift? Did you change yours Phil? There some comments that battery changes need to be registered with the car's onboard computer/battery management on the general internet so it's not clear if it's a DIY job any longer.
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Yes - You can charge the 12 volt battery on your ZS EV with a modern “Smart Charger”.
A few members ( including myself ) have one of the CTEK units.
But a quick on line search will show other makes that do a similar job.
CTEK also sell a fly lead set, with two eyelet terminals.
The live red wire bolts straight to the positive side of your battery, then the black eyelet bolts to an earthing point on the body shell.
The other end has a quick connector, that just plugs into the lead from your charger and you charging in seconds.
This way, you don’t need to faff about use the crocodile clamps.
 
Lovemyev said:
Yes - You can charge the 12 volt battery on your ZS EV with a modern “Smart Charger”.
A few members ( including myself ) have one of the CTEK units.
But a quick on line search will show other makes that do a similar job.
CTEK also sell a fly lead set, with two eyelet terminals.
The live red wire bolts straight to the positive side of your battery, then the black eyelet bolts to an earthing point on the body shell.
The other end has a quick connector, that just plugs into the lead from your charger and you charging in seconds.
This way, you don’t need to faff about use the crocodile clamps.
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Er, he said change, not charge. :)
 
When charging newer cars need to be charged at specific charger points so the current getting into the battery is metered. (Yes i know it said change)

Some cars need to be hooked up to reset the battery monitor system, when changing the battery, but i dont know if this is the case with MG.

These systems should really just reset when power is taken away...Which is often is, if changing the battery :)
 
thinking about it actually, it makes sense for them not to put a big strong battery in there as it doesn't need to power a starter motor to crank an engine, nor does it need to provide the juice for a high torque power steering system like a lot of modern cars that have torque converters for the power steering. You can tell the cars that have the steering powered by the 12v because when the start stop activates and shuts off the engine you can still turn the wheel :)
 
sgt4hed said:
thinking about it actually, it makes sense for them not to put a big strong battery in there as it doesn't need to power a starter motor to crank an engine, nor does it need to provide the juice for a high torque power steering system like a lot of modern cars that have torque converters for the power steering. You can tell the cars that have the steering powered by the 12v because when the start stop activates and shuts off the engine you can still turn the wheel :)
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The problem is, the 12 volt battery they provide is the cheapest and crappiest one they can get away with and it's not really fit for purpose. The accessory battery has to be able to power up all the accessory systems and activate all the contactors before the traction battery kicks in.

The are many posts on EV forums of the 12 volt battery suddenly failing. Happened to me on a carpark with no warning.
 
I changed my 12V battery for a size 096 AGM battery and I haven't seen the low 12V battery warning on the driver display since then so think it's an improvement. The 2 year old SAIC 12V battery is happily giving me about 20Ah (or 250 Wh) without the voltage dropping too far so is still in a reasonable state so I think I have changed it a bit early, or maybe the battery terminals were a bit dirty and not making a brilliant contact when it was in the car. For a new 60Ah battery you shouldn't really take more then about half (30Ah) so 20Ah seems good to me.
 
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