CCU gets very warm when charging.

[Squeak]

Hi all , opened the bonnet on my MG ZS EV 2022 Essence (here in oz) and noticed while changing that the CCU -(Combined Charge Unit) was quite warm when charging. I was very SLOWLY charging the battery pack at 6amps @240 (1.4kw) . Even charging at a high rate a few day prior I was charging @ 15amps (3.1kw) home charging, the CCU was still quite warm. Not liking electronics to get too hot, I installed 4 heat sinks on the posts of the CCU to help keep the unit a bit cooler. The M8 bolt threads were already taped into the posts from the factory. I did remove the Earth cable plastic holders and attach the cable to the left side heat sinks. After 1 hour the CCU was a lot cooler

 

[Cocijo]

I agree, that it’s always a concern when electrics generate excessive heat. I would check on other cars to see if this is normal practice if you can.
I would guess that it is. Here in the UK we could do with harnessing that heat to warm the cabin!

 

[N2STY]

It is designed to get hot that's why there is a heat warning on it and did the heat sink start working or has the water cooling kicked in?

 

[Alb]

Hot is a relative term. What was the actual casing temperature?

 

[Kithmo]

I'd be a bit concerned that those heat sinks may be creating localised cool spots on the PCB inside.

 

[N2STY]

The way I see it is they went for water cooling for a reason

 

[DB Go Rex]

Hi all , opened the bonnet on my MG ZS EV 2022 Essence (here in oz) and noticed while changing that the CCU -(Combined Charge Unit) was quite warm when charging. I was very SLOWLY charging the battery pack at 6amps @240 (1.4kw) . Even charging at a high rate a few day prior I was charging @ 15amps (3.1kw) home charging, the CCU was still quite warm. Not liking electronics to get too hot, I installed 4 heat sinks on the posts of the CCU to help keep the unit a bit cooler. The M8 bolt threads were already taped into the posts from the factory. I did remove the Earth cable plastic holders and attach the cable to the left side heat sinks. After 1 hour the CCU was a lot cooler
View attachment 14333

View attachment 14334

How do you know the level of heat you had was out of spec?

Adding extra stuff is going to cause issues when it comes to a warranty claim, which I suppose is extra important if you are changing the bits that you are concerned about failing…

 

[Coulomb]

The way I see it is they went for water cooling for a reason

And it's still there. This addresses the situation where the heat load isn't enough to trigger the water cooling, I presume.

All heating ages electronics, halving life for every 10°C of temperature rise, due to Arrhenius' law.

 

[rmoyao]

At that level of charge the unit must get warm but not excessively hot. You need to check that the water pump is working.

When charging on AC one of the water pumps is always on. Check that the bigger coolant container is reciclying the liquid. If you do not see any liquid flowing it could be a faulty pump or a blockage on the system.

Obviously you need to check that the level of coolant is fine.

One of the reasons because it is a good idea to charge at a slow rate during the night, is to avoid overheating of the components. Also the battery gets hot during the charge cycle so it is better to slow charge.

At 32 amps rate the CCU gets very hot to my liking. I only use that rate when I need a quick top up. The rest of the charging that I do is during the night at a very slow rate.

 

[Squeak]

I think every one has the wrong idea .. This CCU is getting warm while changing and the car is off. Nothing is running .. only the supply charger that's plugged in, which at the time was charging at 6 amps @240 volt for slow charging. I have a multi charger. 6,8,10 & 15 amps settings

 

[N2STY]

It's basically a transformer what do you expect it to do?

 

[Tim Green]

Most of the above comments are true. However, engineers have designed the system to work and are willing to give a 10 year warranty. Just rely on that.

 

[rmoyao]

I think every one has the wrong idea .. This CCU is getting warm while changing and the car is off. Nothing is running .. only the supply charger that's plugged in, which at the time was charging at 6 amps @240 volt for slow charging. I have a multi charger. 6,8,10 & 15 amps settings

The coolant pump start even if the car is off. Everytime that you charge the pump start