12V Battery replacement?

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We bought our new ZS in Feb 24 but it's build date is quite a long time ago - it has the sunroof!
We had the Road Angel dash cam fitted with permanent power - dealer fit using the piggy back fuse holders. It's set to shut off at 12.4V I think.
Anyway we have been having low 12V battery warnings even though we drive it every few days. I have just mains charged the car (Zappi charger) and the 12V battery is at 12.7V when driving the dash tells me it's being charged at 14.8 volts.
As we are getting the 12V battery warnings and it was sitting somewhere for over a year before we bought it I guess the 12V battery has been drained too much so is in need of a replacement. Nearest dealer can book it in for 20th June (3 weeks) but I'm not convinced they will find anything as I will have driven 30 miles to them and don't really want to leave it with them for a few days as I can't get back home. Plus I don't really want to waste a day if they can't find anything and for it then to cause me more issues later.

Anyway does anyone know if you can just buy a replacement 12V battery and fit it the same as you would do in a petrol or diesel car? If so any idea what type of battery that's required or is it best to buy one from MG?
Thanks for any help you can offer.
 
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We bought our new ZS in Feb 24 but it's build date is quite a long time ago - it has the sunroof!
We had the Road Angel dash cam fitted with permanent power - dealer fit using the piggy back fuse holders. It's set to shut off at 12.4v I think.
Anyway we have been having low 12v battery warnings even though we drive it every few days. I have just mains charged the car (Zappi charger) and the 12v battery is at 12.7v, when driving the dash tells me it's being charged at 14.8 volts.
As we are getting the 12v battery warnings and it was sitting somewhere for over a year before we bought it I guess the 12v battery has been drained too much so is in need of a replacement. Nearest dealer can book it in for 20th June (3 weeks) but I'm not convinced they will find anything as I will have driven 30 miles to them and don't really want to leave it with them for a few days as I can't get back home. Plus I don't really want to waste a day if they can't find anything and for it then to cause me more issues later.

Anyway does anyone know if you can just buy a replacement 12v battery and fit it the same as you would do in a petrol or diesel car? If so any idea what type of battery that's required or is it best to buy one from MG?
Thanks for any help you can offer.
I know naff all about the ZS but I’d suggest a trip to the dealer - there were software updates that affect charging the 12V for many cars, not sure on ZS and I believe the warranty is for upto £99 if they have to replace within 12 months but the software is the bit that I’d query. Personally also I’d move the piggy back to a switched live unless 24/7 is essential.

You can indeed buy batteries Tanya list them. I believe an upgrade is the AGM type as pretty sure the cars come with a poor quality flooded battery.
 
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Also speak nicely to your dealer - when my 4 was in for a water leak ruddy boot. I got a courtesy car and might have wangled it for free as I was a decent human being.
 
Anyway does anyone know if you can just buy a replacement 12v battery and fit it the same as you would do in a petrol or diesel car? If so any idea what type of battery that's required or is it best to buy one from MG?
Thanks for any help you can offer.

As @gazza487 says, ask for courtesy car if they can't fix it whilst you wait and ask them to fix it under the warranty, whatever the problem is - their problem. Preferably the same dealer that fixed your camera.
What is the build date of your car?
 
The charge level of my battery was also low once. It is important to press the brake pedal firmly when switching the car on and off. Since I have been doing this, the charge level has been fine.
 
I know naff all about the ZS but I’d suggest a trip to the dealer - there were software updates that affect charging the 12V for many cars, not sure on ZS and I believe the warranty is for upto £99 if they have to replace within 12 months but the software is the bit that I’d query. Personally also I’d move the piggy back to a switched live unless 24/7 is essential.

You can indeed buy batteries Tanya list them. I believe an upgrade is the AGM type as pretty sure the cars come with a poor quality flooded battery.
yes its a flooded battery. usually only last about 3years. if unused and sat they dont really hold charge where as an AGM does. im a former warranty battery tester/manager for platinum batteries. I personally vouch the AGM.
 
yes its a flooded battery. usually only last about 3years. if unused and sat they dont really hold charge where as an AGM does. im a former warranty battery tester/manager for platinum batteries. I personally vouch the AGM.
Thanks. Is the MG capable of charging AGM batteries to their correct voltage? I understood AGM need 0.5V more on both bulk and float charge to reach 100% charged?
 
We bought our new ZS in Feb 24 but it's build date is quite a long time ago - it has the sunroof!
We had the Road Angel dash cam fitted with permanent power - dealer fit using the piggy back fuse holders. It's set to shut off at 12.4V I think.
Anyway we have been having low 12V battery warnings even though we drive it every few days. I have just mains charged the car (Zappi charger) and the 12V battery is at 12.7V when driving the dash tells me it's being charged at 14.8 volts.
As we are getting the 12V battery warnings and it was sitting somewhere for over a year before we bought it I guess the 12V battery has been drained too much so is in need of a replacement. Nearest dealer can book it in for 20th June (3 weeks) but I'm not convinced they will find anything as I will have driven 30 miles to them and don't really want to leave it with them for a few days as I can't get back home. Plus I don't really want to waste a day if they can't find anything and for it then to cause me more issues later.

Anyway does anyone know if you can just buy a replacement 12V battery and fit it the same as you would do in a petrol or diesel car? If so any idea what type of battery that's required or is it best to buy one from MG?
Thanks for any help you can offer.
My 12 v packed up after 13 months and as it was out of guarantee I got a Bosch battery and that is good. No more low volts if I do not use the car for 3 or 4 days. Mechanic told me the original fitted are ( rubbish) cleaned his work up. Bosch has a 5 year guarantee as long as you do 3,000miles a year.
 
Thanks. Is the MG capable of charging AGM batteries to their correct voltage? I understood AGM need 0.5V more on both bulk and float charge to reach 100% charged?
The AGM battery was built for stop/start cars. you can fit it to any car its like an upgrade. When a car is produced they give it a certain battery for that car, eg my 2015 mokka 1.4t has an AGM i cant fit flooded battery as its downgrading to a flooded and wont do the job it will flatten in weeks. An AGM holds its charge and your charger when plugged in will charge it and main battery. A battery is considered flat below 12.6V above it its charged. but its not just the voltage its the cca cold crank amps that starts car. if this is 20% under its stated amps and does not come up when charged then the battery has died. i would suggest get battery tested but insist on an AGM also make sure its above 12.6V when fitted and have them test it for its cca. give us a shout if need anything else on batteries
 
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You may just have a dud battery that should be replaced under warranty. Mine gave heaps of trouble from time of delivery and was replaced and installed under warranty (at home by the mobile suport team) after 2 weeks.
 
Bit of an update:
I disconnected the 12V battery negative for 5 mins today in case that would reset things.
Well when driving the 12V battery' is now being charged at 14 volts not 14.8V! No idea if this is significant or not.
Also it's still sitting at 12.8V after a few hrs sitting on the driveway!
I'll have to watch it over the next few days!
 
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The charge level of my battery was also low once. It is important to press the brake pedal firmly when switching the car on and off. Since I have been doing this, the charge level has been fine.
Hi, this is news to me that it is useful to press the brake pedal when switching the car off. I'd like to hear more about that - is there a reference in the manual, or were you told that by someone? Thanks.
 
Hi, this is news to me that it is useful to press the brake pedal when switching the car off. I'd like to hear more about that - is there a reference in the manual, or were you told that by someone? Thanks.
never heard that one. I just hit the start stop button on my 22 plate zs ev. never had prob with battery.
 
Do you use the DAB radio? Somewhere on here is a thread about a bug when the radio is left tuned to station it can't find. The radio stays on searching, even while the car is off. I had huger problems a while ago, and I think that may have been the cause. I had tuned to a South Wales station, then driven to the Midlands. It then picked up a Brummie station, which obviously it lost when I returned home.

"Unfortunately" I found out about this at the same time my dealer changed the battery, so I can't be sure of cause and effect.
 
The AGM battery was built for stop/start cars. you can fit it to any car its like an upgrade.
Thats bad advice and wrong. The vehicle charging system has to be capable of charging the relevant chemistry.

Flooded battery
Charging Voltage Bulk 14.2V
Float 13.4V

AGM
Charging Voltage Bulk 14.7V
Float 13.8V

Flooded batteries can handle much higher discharge rates (not relevant for EV's), AGM having lower self discharge is better for RV's, boats, caravans etc.

It is essential that the charging system is capable of charging AGM, it's not a straight swap as you suggest. Charging AGM with Flooded setting would result in the battery not being fully charged and thus effectively having a lower capacity than stated.


When a car is produced they give it a certain battery for that car, eg my 2015 mokka 1.4t has an AGM i cant fit flooded battery as its downgrading to a flooded and wont do the job it will flatten in weeks.
No so, it would do the job fine but be constantly over charged due to the higher voltage. This in turn would shorten it's life.

An AGM holds its charge and your charger when plugged in will charge it and main battery. A battery is considered flat below 12.6V above it its charged. but its not just the voltage its the cca cold crank amps that starts car.
CCA would be more applicable to petrol / diesel cars, no so much with an EV. Generally the advice with lead acid is not to get below 50% and the voltage for 50% is 12.25V on AGM, 12.23 on Flooded. The internal resistance of the battery is what scuppers the CCA, as the battery ages and or suffers abuse, the resistance increases thereby limiting it's ability to hold up the voltage under load.


if this is 20% under its stated amps and does not come up when charged then the battery has died.
It may not really be a deciding factor for an EV application.

I would suggest get battery tested but insist on an AGM also make sure its above 12.6V when fitted and have them test it for its cca.
Make sure it's like for like replacement if AGM original fit replace with AGM, if it's flooded ditto, just choose a good make. A good indicator to the quality of a battery is the weight, heavier = more lead !
give us a shout if need anything else on batteries
 
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Thats bad advice and wrong. The vehicle charging system has to be capable of charging the relevant chemistry.

Flooded battery
Charging Voltage Bulk 14.2v
Float 13.4v

AGM
Charging Voltage Bulk 14.7v
Float 13.8v

Flooded batteries can handle much higher discharge rates (not relevant for EV's), AGM having lower self discharge is better for RV's, boats, caravans etc.

It is essential that the charging system is capable of charging AGM, it's not a straight swap as you suggest. Charging AGM with Flooded setting would result in the battery not being fully charged and thus effectively having a lower capacity than stated.



No so, it would do the job fine but be constantly over charged due to the higher voltage. This in turn would shorten it's life.


CCA would be more applicable to petrol / diesel cars, no so much with an EV. Generally the advice with lead acid is not to get below 50% and the voltage for 50% is 12.25v on AGM, 12.23 on Flooded. The internal resistance of the battery is what scuppers the CCA, as the battery ages and or suffers abuse, the resistance increases thereby limiting it's ability to hold up the voltage under load.



It may not really be a deciding factor for an EV application.


Make sure it's like for like replacement if AGM original fit replace with AGM, if it's flooded ditto, just choose a good make. A good indicator to the quality of a battery is the weight, heavier = more lead !
Well said.
 
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