Do any quality manufacturers offer 12v batteries for MG4?

GameZone

Established Member
Joined
Aug 12, 2023
Messages
309
Reaction score
195
Points
94
Norway
Driving
MG4 Trophy LR
I want another 12v battery in my garage, but quality manufacturers like Varta and Bosch obviously doesn't have it. Is the only option another battery from MG itself, or are there alternatives?
 
The battery in the mg4 wont be a unique form factor, have you checked the battery to see if it has the size code on it
Screenshot_2023-10-03-14-43-16-222_com.android.chrome.jpg
 
The battery in the mg4 wont be a unique form factor, have you checked the battery to see if it has the size code on itView attachment 20516
Thanks that helpful. No haven't checked yet. Can any 12v battery with this size be used?

Will this work?


Do anyone know if that Varta battery will workbwith my M4?
 
Last edited:
I’m not an expert in this, but car batteries are typically designed for delivering a large amount of power for a short time to crank start the ICE. The EV 12v batteries may have different specs for the different load type.

I’d just do some research first.
 
I’m not an expert in this, but car batteries are typically designed for delivering a large amount of power for a short time to crank start the ICE. The EV 12v batteries may have different specs for the different load type.

I’d just do some research first.
That's what I'm trying to do.
 
I’m not an expert in this, but car batteries are typically designed for delivering a large amount of power for a short time to crank start the ICE. The EV 12v batteries may have different specs for the different load type.

I’d just do some research first.
I suppose if the heater is on, it could draw quite a lot, presumably from the 12v side. Not as much, or for as short a duration as engine cranking, but probably rules out using something like a lithium battery for this, apart from the different recharge regime.
 
The needs of the stop start specced batteries are akin to the uses of our EVs which is why brands like varta are rejigging their current lineup descriptions to include EV terminology

So basically what I was getting at but forgot to say is get the largest amp hour capacity stop start battery you can fit and afford
 
I suppose if the heater is on, it could draw quite a lot, presumably from the 12v side. Not as much, or for as short a duration as engine cranking, but probably rules out using something like a lithium battery for this, apart from the different recharge regime.
The cabin heater fan blower motor, is powered by the 12 volt battery under the bonnet.
The heating element that provides the heat however, draws it power from the HV traction battery.
The power consumed by the blower motor is fairly low, its the heater element that is the hungry beast.
ICE cars tend to be fitted with a 12volt battery that has a high amperage ( CCA) because the current drawn by the starter motor when turning the engine in winter conditions, is very high.
Manufactures are constantly trying the reduce the weight in their cars, so heavy 12 volt batteries are a target.
Alternator output can soon replace the power used to start the car.
Batteries are costly so size and weight is kept to a minimum.
 
The cabin heater fan blower motor, is powered by the 12 volt battery under the bonnet.
The heating element that provides the heat however, draws it power from the HV traction battery.
The power consumed by the blower motor is fairly low, its the heater element that is the hungry beast.
ICE cars tend to be fitted with a 12volt battery that has a high amperage ( CCA) because the current drawn by the starter motor when turning the engine in winter conditions, is very high.
Manufactures are constantly trying the reduce the weight in their cars, so heavy 12 volt batteries are a target.
Alternator output can soon replace the power used to start the car.
Batteries are costly so size and weight is kept to a minimum.
I was going to query this then did a bit of Googling. It seems you're right:

 
I notice if I run the pre-heat on my car when it's charged to 100% (after going out and unplugging the charger lead, grrrr...) the battery is at 98% by the time I get in.
 
The bundled SAIC battery is just a small ICE car battery, it is very cheap and light (for a conventional 12V car battery)..

Almost anything quality will be better, as mentioned by others a leisure battery will last longer (but also probably cost more).

There is space for a larger battery but there's not a lot of point having something with huge capacity (and no point at all in cranking amps!): it is the ability to withstand lots of cycles that is key, hence why leisure batteries are good because they are designed for this.
 
I was going to query this then did a bit of Googling. It seems you're right:
You sound a little shocked @siteguru 🤣.
Below is photo taken from a Tesla.
The system in the MG models will be very similar.
With the interior trim removed at the side of the heater unit, you can clearly see the orange coloured high voltage cables carrying power to the PTC heater element.
The much smaller sized wiring loom above are for the fan blower motor ( the hamster wheel ) will be powered by the 12 volt battery.
It makes sense really, as the element in PTC heater would totally discharge a 12 volt battery in minutes ( but I doubt it could even run it at all ).
PTC heater works in a similar manner as a basic home electric fire.
All other electrical items, are powered from the 12 volt battery.

Tesla HV heater wiring 2021-06-24 at 21.09.38.png
 
The bundled SAIC battery is just a small ICE car battery, it is very cheap and light (for a conventional 12V car battery)..
If you search around the car you'll find references to premium components (CATL, Bosch, Varta, contitech et. al.) : my understanding is that Varta is the battery for the 12v system. Normally these last 5years+, its normally degredation of the connectors, rather than the battery itsself - i know this from Tayna Batteries, who are my goto supplier / warranty experts (when Ive sent a battery back for checking)
 
If you search around the car you'll find references to premium components (CATL, Bosch, Varta, contitech et. al.) : my understanding is that Varta is the battery for the 12v system. Normally these last 5years+, its normally degredation of the connectors, rather than the battery itsself - i know this from Tayna Batteries, who are my goto supplier / warranty experts (when Ive sent a battery back for checking)
My 12V battery is clearly marked as an SAIC made component.
 
The needs of the stop start specced batteries are akin to the uses of our EVs which is why brands like varta are rejigging their current lineup descriptions to include EV terminology

So basically what I was getting at but forgot to say is get the largest amp hour capacity stop start battery you can fit and afford
The battery the dealer told me to get isn't start stop technology at all
 
The battery the dealer told me to get isn't start stop technology at all
Indeed - start/stop batteries are designed to repeatedly crank over an ICE engine, which is an utterly different workload. Cranking is irrelevant to EVs: they need a battery that can last for deep cycles of low power draw, such as a leisure battery for camping.

A fuller explanation of the differences between different types of 12V battery is here:
 
The battery the dealer told me to get isn't start stop technology at all

It's not my own words I'm quoting
Indeed - start/stop batteries are designed to repeatedly crank over an ICE engine, which is an utterly different workload. Cranking is irrelevant to EVs: they need a battery that can last for deep cycles of low power draw, such as a leisure battery for camping.
Is it really a very different workload, wouldn't the alternator of an ice kicking in when the engine restarts when the charge gets low be akin to our HV battery charging the 12v when that gets low. Varta are a very big batter manufacturer and it's their views/research I was making suggestions from

I'm not concerned about CCA, only amp h capacity
 
The battery type that should be installed is a Deep Cycle battery. These will normally have a higher amp hour rating than an automotive battery that will have a CCA rating. A deep cycle battery is designed to withstand a constant discharge over a period of time and then be recharged again for re-use. They also are more expensive but last much longer than an automotive battery that has to supply a huge amount of power very quickly to turn an engine over.

Deep Cycle batteries do not have a CCA (Cold Cranking Amps) value so any battery you see saying it has 600 CCA or whatever is the wrong type. CCA tells you how many amps a 12-volt battery may support for 30 seconds at -17.8 degrees Celsius before the voltage drops to at least 7.2 volts per cell.
 
Support us by becoming a Premium Member

Latest MG EVs video

MG4 + MG5 + MG ZS EV Chat
Subscribe to our YouTube channel
Back
Top Bottom