Anyone else getting dcdc charge fault & more errors leading to MG5 breakdown?

[MickeySw]

Cheers, yeah I fitted a new 12v battery got the car driving and took it to a Rapid charge! It accepted the charge but when driving the battery only showing 11.8 and when I got home its not accepting an AC charge! I’ll get it booked into the EV garage tomorrow but it’s obviously a part needed that allows an AC charge and that works like an alternator on an ICE vehicle?!?!

The CCU (Combined Charge Unit) in a MG5 has two functions:

• provide low voltage power (14V ish) when driving or charging
• convert AC mains voltage into DC battery voltage during Type1/2 charging

You’re correct, it certainly looks like the CCU is defective (or fuse ‘M’ under the hood has blown)

It’s essential to externally charge the 12V aux before you attempt to drive it again as it currently provides all low voltage power which it’s not designed to do.

 

[Richierich37]

The CCU (Combined Charge Unit) in a MG5 has two functions:

• provide low voltage power (14V ish) when driving or charging
• convert AC mains voltage into DC battery voltage during Type1/2 charging

You’re correct, it certainly looks like the CCU is defective (or fuse ‘M’ under the hood has blown)

It’s essential to externally charge the 12V aux before you attempt to drive it again as it currently provides all low voltage power which it’s not designed to do.

Cheers man,

I’ve just fitted a brand new 12V battery and have about 76% range left so hopefully that’ll be enough to get me to the EV garage to let the professionals deal with it!

 

[MickeySw]

I’ve just fitted a brand new 12v battery and have about 76% range left so hopefully that’ll be enough to get me to the EV garage to let the professionals deal with it!

It’s highly recommended to externally charge even a brand new 12V aux overnight as you don’t know how long it’s been sitting on a shelf.

The car will shut down immediately once the 12V aux goes below a certain limit (11.8V is too close for comfort imho), regardless of the SoC of the main battery.

 

[Coulomb]

Yes, charge the 12V battery with an ordinary 12V battery charger! The car could shut down any moment with only 11.8V.

 

[Richierich37]

It’s highly recommended to externally charge even a brand new 12V aux overnight as you don’t know how long it’s been sitting on a shelf.

The car will shut down immediately once the 12V aux goes below a certain limit (11.8V is too close for comfort imho), regardless of the SoC of the main battery.

Ok thanks, any idea how long it can drive for if not using any 12V stuff in car? The EV garage is about 30 mins away on the motorway

 

[kevin ellard]

Ok thanks, any idea how long it can drive for if not using any 12v stuff in car? The EV garage is about 30 mins away on the motorway

Tricky question to answer. Try to turn off everything electrical. I think the lights will still be on but the battery can cope with those. Does anyone know if there is a way to shut the infotainment system down as much as possible? If you've got an alternate route , I'd consider it. Recovery will be more complicated on the motorway.

 

[Richierich37]

Tricky question to answer. Try to turn off everything electrical. I think the lights will still be on but the battery can cope with those. Does anyone know if there is a way to shut the infotainment system down as much as possible? If you've got an alternate route , I'd consider it. Recovery will be more complicated on the motorway.

Didn’t want to risk it so I’ve arranged a Recovery Company to lift the car tomorrow morning and deliver it to the EV garage! Just not worth the hassle of breaking down on way there! I’ll keep you posted with the EV garage diagnostics!

 

[Richierich37]

Tricky question to answer. Try to turn off everything electrical. I think the lights will still be on but the battery can cope with those. Does anyone know if there is a way to shut the infotainment system down as much as possible? If you've got an alternate route , I'd consider it. Recovery will be more complicated on the motorway.

Well the EV garage are 99% it’s the onboard charger that’s gone and unfortunately they can’t fix it as it’s a MG dealer part only that needs coded to the car! They are running more checks and will confirm tomorrow! The part is over £2k alone ***