Charging MG 4Trophy

[jackhill1]

I have been charging my MG 4 for 6 months without a problem with my Podpoint charger which is 7kW charger, but when I view the charging rate it shows only 5.5 kW. Is this correct.

 

[stevegus]

I have a 7kw charger but only at best manage 6.2kwh , most of the time its even down to 5.8 kwh , it is dependant on the electricity , in my are we dont get the 240 volts but its 216 volts which when i connect the car will go down to 183 volts .

The cables is your installation are too small and are causing a resistive drop. Thats a lot of heat in the cabling

 

[tsedge]

I have a 7kW charger but only at best manage 6.2kW , most of the time its even down to 5.8 kW. It is dependant on the electricity supply, in my area we don't get the 240 volts but it's 216 volts which when I connect the car will go down to 183 volts .

Sounds like the supply is struggling in your area. I do not know what is expected in Malta, but I suggest you have it checked by a qualified electrician.

 

[Coulomb]

I suggest you have it checked by a qualified electrician.

Agreed. Something somewhere is dropping a lot of voltage, and must be dissipating kilowatts of power. That's likely to cause a fire, unless it's distributed along a very long cable.

@nexia201, are you perhaps at the end of a Single Wire Earth Return system? Those are notorious for poor voltage regulation at high loads.

 

[Muffler]

I have an older ‘dumb’ 7kW wallbox so unable to accurately see input but on the car side of things it consistently shows around 6.1-6.2kW

 

[johnnyboy]

I have been charging my MG 4 for 6 months without a problem with my Podpoint charger which is 7kw charger, but when I view the charging rate it shows only 5.5 kw. Is this correct.

If everyone is using their chargers at the same time, then the rate of charge will be reduced. It will all depend on the time you set your car for charging. If there are a large number of cars charging from your particular sub station at night then this will reduce your charge

 

[Coulomb]

The other thing to consider is that the car's on-board charger may be rated at less than 7kW, e.g. some models are rated at 6.6kW. I think that's at the charger's input, so the output would be some 6% less.

Also the car reports net power into the battery, since this is what is relevant for estimating the charge end time. So power used by the rest of the car takes away from the reported charge power.

 

[Coulomb]

when I asked UKPN (who have been a brilliantly helpful DNO throughout all our electrical installations) to put in a100A fuse they couldn't; but only because the tails to the CU were only 16mm² (not 25mm²) ...

I think that the tails being too thin is an excellent reason not to install a 100 A fuse!

 

[Coulomb]

If everyone is using their chargers at the same time, then the rate of charge will be reduced.

That's if the charger is smart enough to recognise the control tones to throttle the output, and if the supply authority has the equipment and monitoring in place. It's my no means automatic.

If you're talking about public charging, then yes, often the site will have a power limit and a mechanism to share the limited power reasonably equitably. But it sounds to me that the OP is charging from home.

 

[rjhfandclf]

I think that the tails being too thin is an excellent reason not to install a 100 A fuse!

Indeed! I was just grateful that he confirmed my belief that getting yet another electrician in just to change the CU tails was overkill - where others keep saying you MUST have 100A for an EV charger!