Jump Starting an MG4 SR

[JonEV]

Hopefully someone a little smarter than myself knows the answer to this.

I have the 12V drain issue which I should be resolved by a quick software update.
However, until my local MG garage find the time to fit me in, am I okay to jump the 12V system using jump leads and a nearby ICE car (with the owners permission of course).
I see a lot of talk about boosters and assume they will perform the same function, just wanted to check.

 

[Vingnut]

It is ok to jumpstart the MG4 from another car, but what must never happen is the other way to other car than an EV.
In other words, never jumpstart an ICE car from an EV as the EV startbattery is to smal and you risk to kill your EVs battery charger (very very expensive). I think this is highlited somewhere in the manual.

The jumpstart procedure is found in page 263-264 in the manual.

P.s. No need to have the ICE car running when jumpstarting an ev and be sure to remove the jumpstarting cables as son the MG4 is in ready state.

 

[JonEV]

Thank you, I was searching the manual but couldn't see anything.

 

[Rolfe]

You can also get batteries - both lead-acid and lithium ion - with jump leads attached which will do the job without needing to go cap in hand to an ICE car owner. Many people keep a lithium ion one (small and quite light) in the car just in case.

 

[kiwi]

A lithium battery jump pack to power up a lead acid battery to power up a lithium traction battery… what do you need as a back up to the jump pack? ?

 

[JonnyG]

You can also get rechargeable jump starters on Amazon for around £50 - £100 and keep it handy in the car. Just remember to charge it up occasionally.

 

[Brettus]

A lithium battery jump pack to power up a lead acid battery to power up a lithium traction battery… what do you need as a back up to the jump pack? ?

The 12v socket of the car. It’s like having two buckets with holes in them. ?

 

[Evgen K]

It is ok to jumpstart the MG4 from another car, but what must never happen is the other way to other car than an EV.
In other words, never jumpstart an ICE car from an EV as the EV startbattery is to smal and you risk to kill your EVs battery charger (very very expensive). I think this is highlited somewhere in the manual.

The jumpstart procedure is found in page 263-264 in the manual.

P.s. No need to have the ICE car running when jumpstarting an ev and be sure to remove the jumpstarting cables as son the MG4 is in ready state.

Very interesting, thanks for this post but ... most jump starters with battery packs have short wires and are connected directly to contacts of 12V battery.

Is it correct connection schema or i should search unpainted metal surface in car to join negative terminal as MG documentation says?

 

[Seajays]

Very interesting, thanks for this post but ... most jump starters with battery packs have short wires and are connected directly to contacts of 12V battery.
View attachment 29576
Is it correct connection schema or i should search unpainted metal surface in car to join negative terminal as MG documentation says?
View attachment 29577

The reason they suggest that is the final connection (being the negative of the donor to the negative of the "disabled" vehicle), may cause a spark when you connect it.

Sometimes 12v batteries can vent flammable hydrogen gas, so it's to avoid the possibility of the spark igniting them.

However, you don't necessarily have to do that with a battery pack, as you don't switch it on until it is connected, therefore no spark...

 

[Evgen K]

The reason they suggest that is the final connection (being the negative of the donor to the negative of the "disabled" vehicle), may cause a spark when you connect it.

Sometimes 12v batteries can vent flammable hydrogen gas, so it's to avoid the possibility of the spark igniting them.

However, you don't necessarily have to do that with a battery pack, as you don't switch it on until it is connected, therefore no spark...

Thank you for the answer. Could you please give advice how to better connect battery jump starter to 12V battery in the car (MG4)? Can I connect it directly to positive and negative terminals of 12V battery or is it better to connect positive wire to battery positive terminal and negative wire to unpainted metal surface in the car?
Thanks.

 

[T1 Terry]

If you can reach an alloy part with the negative jump cable, that will be connected to the 12v battery, but far enough away to avoid sparks igniting the gasses from a crook lead acid battery. Once my 12v lead acid battery passes on to that great scrape battery dealer in the sky, I'll be fitting an LFP battery in its place .... no fumes or gasses, last for a long time and a much smaller, lighter LFP battery will have all the storage needed for the MG4 .... pulling big amps for the steering as an example, hard on a lead acid battery, no problem for an LFP battery .....

T1 Terry

 

[Vingnut]

Thank you for the answer. Could you please give advice how to better connect battery jump starter to 12V battery in the car (MG4)? Can I connect it directly to positive and negative terminals of 12V battery or is it better to connect positive wire to battery positive terminal and negative wire to unpainted metal surface in the car?
Thanks.

As mentioned the reason for having the battery needing a jump normally not connected on both terminals (negative somewhere else in the car) is the possibility for hydrogen gases being vented from the empty battery (actually it's when a battery is charged it vents gases or if it's damaged).
To be honest, if your battery compartment have been well ventilated for some minutes this will normally not be a problem. Using a battery booster this will only be a problem if one needs to move the clamps for better connection after turning it on.

That said I have once been blasted 2 feet off the ground up a wall from a battery gas explosion (big bus batteries) when accidentally shorting the terminals with the steel battery cover (that same cover also saved if not my life, my eyesight, face and probably more). Where I was not shielded my uniform (happened when I was in the Norwegian army) was totaly destroyd by acid by the next day, so this is not a matter to be taken lightly though.

 

[Archev]

As mentioned the reason for having the battery needing a jump normally not connected on both terminals (negative somewhere else in the car) is the possibility for hydrogen gases being vented from the empty battery (actually it's when a battery is charged it vents gases or if it's damaged).
To be honest, if your battery compartment have been well ventilated for some minutes this will normally not be a problem. Using a battery booster this will only be a problem if one needs to move the clamps for better connection after turning it on.

That said I have once been blasted 2 feet off the ground up a wall from a battery gas explosion (big bus batteries) when accidentally shorting the terminals with the steel battery cover (that same cover also saved if not my life, my eyesight, face and probably more). Where I was not shielded my uniform (happened when I was in the Norwegian army) was totaly destroyd by acid by the next day, so this is not a matter to be taken lightly though.

Where’s the nearest Norwegian Army Surplus uniform store ??