MG4 Charging efficiency

[TonyWilk]

I'm using the 'Granny charger' that came with the car (MG4 Trophy) and plugged it into a cheap 'Energy Monitor' to get some idea of how much 'leccy I'm using.
Just charged from 48% to 80% which should be nearly 20kwh, the meter said 25.1kwh which is about 80% efficient.
Anyone else got numbers on this ?
Is it good/bad/average ?
Would a wall charger (e.g. Zappi) be any different ?

 

[Robf]

I would always recommend you get a wall box (zappi or similar if you have solar panels, other options if not) to charge the car. It allows you to charge effectively on cheap rates e.g. Octopus Go. Granny chargers are generally accepted as being a temporary measure and may not last long if used constantly.

 

[tsedge]

I'm using the 'Granny charger' that came with the car (MG4 Trophy) and plugged it into a cheap 'Energy Monitor' to get some idea of how much 'leccy I'm using.
Just charged from 48% to 80% which should be nearly 20kwh, the meter said 25.1kwh which is about 80% efficient.
Anyone else got numbers on this ?
Is it good/bad/average ?
Would a wall charger (e.g. Zappi) be any different ?

Do you mean your electricity meter? That will also include your house running costs during the same time, or do you mean the meter on the car?

I would expect a granny charger to perhaps be slightly less efficient but not really sure if the heat losses would be significant. There will be an efficiency loss.

 

[Deleted member 9909]

You can lose over 10% at the cars inverter to start with....average car inverter loses between 10 and 20% depending on design

 

[TonyWilk]

Do you mean your electricity meter? That will also include your house running costs during the same time, or do you mean the meter on the car?

I would expect a granny charger to perhaps be slightly less efficient but not really sure if the heat losses would be significant. There will be an efficiency loss.

I have the charger plugged into one of these:

Using the granny charger 'cos I don't want a wallbox yet (planning to have a boatload of solar+storage early next year so it'll get sorted then)

 

[BugEyed]

Inverters have both fixed and variable losses, meaning that you lose a significantly higher % at low charge rates than at higher charge rates. For example you should expect to lose around 12-15% at 7kW. Whether that justifies the cost of the installation of a proper charge point is open to debate.

 

[siteguru]

The other advantage of a wall box is that you don't have the risk of needing to do a long journey the next day and not having enough time to charge the car - a full charge can be done overnight on a wall box, but can't on a granny cable.

 

[jon0881]

The granny charger and wallbox (7kw) will be using AC and your car is DC. There is losses on the transport of the AC but the losses on the car converting it to DC to be stored will be the difference. The kw is the unit of energy stored and the difference between the AC units used will not be the same as the units arriving in the battery

 

[Deleted member 9909]

The granny charger and wallbox (7kw) will be using AC and your car is DC. There is losses on the transport of the AC but the losses on the car converting it to DC to be stored will be the difference. The kw is the unit of energy stored and the difference between the AC units used will not be the same as the units arriving in the battery

The inverter as stated above.......

 

[jon0881]

The inverter as stated above.......

Yes i read that but maybe the OP didnt know that the charger is AC and battery was DC and the kw are just units of energy

 

[siteguru]

The inverter as stated above.......

/Pedant-Mode-On

An inverter is what is used for the V2L circuit - to convert battery DC to AC voltage. AC to DC is a converter.

Converter vs Inverter - Difference and Comparison | Diffen

What's the difference between Converter and Inverter? Converters and inverters are electrical devices that convert current. Converters convert the voltage of an electric device, usually alternating current (AC) to direct current (DC). On the other hand, inverters convert direct current (DC) to...

www.diffen.com

/Pedant-Mode-Off

 

[jon0881]

/Pedant-Mode-On

An inverter is what is used for the V2L circuit - to convert battery DC to AC voltage. AC to DC is a converter.

Converter vs Inverter - Difference and Comparison | Diffen

What's the difference between Converter and Inverter? Converters and inverters are electrical devices that convert current. Converters convert the voltage of an electric device, usually alternating current (AC) to direct current (DC). On the other hand, inverters convert direct current (DC) to...

www.diffen.com

/Pedant-Mode-Off

Apologies, had my solar hat on

 

[Deleted member 9909]

An inverter is what is used for the V2L circuit - to convert battery DC to AC voltage. AC to DC is a converter.

Point well made. Convertor ac to dc battery, inverter dc battery to ac motor

So losses at converter and inverter to factor in...

 

[Rip Van]

Point well made. Convertor ac to dc battery, inverter dc battery to ac motor

So losses at converter and inverter to factor in...

Hmm, used to(?) call AC to DC, rectifiers.

 

[Deleted member 9909]

Let's call it ev charging (ac to dc) and inverter dc to ac then for simplicity

When it comes to electric vehicles, the converter is built inside the car. It's called the "onboard charger" though it really is a converter. It converts power from AC to DC and then feeds it into the car’s battery. This is the most common charging method for electric vehicles today and most chargers use AC power.

 

[jon0881]

......unless you are using a DC charger