Logging charging stats

Is there any app or device that we can use to keep track of how many kWh we put into the MG4 ?

coff33 said:

Is there any app or device that we can use to keep track of how many kWh we put into the MG4 ?

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You can use an OBD2 dongle to precisely know exactly how much juice made it into the battery. And an app to record that information.
I use OBDLink MX+ and CarScanner.

One I used for my ICE cars is Spritverbrauch berechnen und Autokosten verwalten - Spritmonitor.de it now supports EV’s, I will admit I have not tried it For my EV but was good for petrol tracking

( End% - Start% ) x Usable Capacity ??

e.g. ( 100% - 40% ) x 50.8 = 30.48kWh

Your charger should know how much it has sent - certainly the ZAPPI records daily, monthly data on charges (plus whatever purchased from external sources)

siteguru said:

( End% - Start% ) x Usable Capacity ??

e.g. ( 100% - 40% ) x 50.8 = 30.48kWh

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This doesn't account for losses in the car as it will only show what's in the pack not what's lost at the conversion point in the obc

The OP is asking about kWh put into the car. By that I assume they mean kWh put in the battery ... that calculation does exactly that (within bounds of tolerance).

Total kWh delivered from the supply should usually be obtainable via the charge point app. Thus overall efficiency can be calculated ... ( Power Stored / Power Delivered ) x 100%

siteguru said:

The OP is asking about kWh put into the car. By that I assume they mean kWh put in the battery ... that calculation does exactly that (within bounds of tolerance).

Total kWh delivered from the supply should usually be obtainable via the charge point app. Thus overall efficiency can be calculated ... ( Power Stored / Power Delivered ) x 100%

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Where as an electrical engineer I'd take it to be what was actually put into the car not what it stored

coff33 said:

Is there any app or device that we can use to keep track of how many kWh we put into the MG4 ?

Click to expand...

Another option if you use a granny charger like myself is to use a smart plug with power monitoring. I got the idea from other users on this very forum.
I bought a basic Tapo P110 and installed the Tapo app. It only uses WiFi unfortunately and the signal at the front of my house is weak with the router I’ve got, but sufficient to operate the plug remotely.
Innr makes a zig bee compatible plug but it’s more expensive.
The Tapo app that ‘comes with the plug’ is ok. You can export the kWh fed into the granny charger in real time.
There’s another app called Watt which is compatible with Tapo and Kasa devices and brings them all under one app. And that has a few more options.

I use the plug to make sure I know how much I charge so I can add it to the electricity bill pot.

I also automate the charger so when I pull up on the drive and I disconnect my phone from car play the system automatically switches on the plug. And when I connect car play on my drive the system switches it off.

Ayoull said:

Where as an electrical engineer I'd take it to be what was actually put into the car not what it stored

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I guess I'm not understanding you - my reply above covers both aspects as far as I can see? Energy Delivered (what's put in the car*) vs Energy Stored (what's put in the battery).

* I accept that the charge point app will include losses between the charge point and the onboard charger (i.e. the car's port), but these will be so minimal as to be near-enough irrelevant.

siteguru said:

I guess I'm not understanding you - my reply above covers both aspects as far as I can see? Energy Delivered (what's put in the car) vs Energy Stored (what's put in the battery).

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Theres a difference to what is put into the car which is the total power transferred from the supply to the car.

To what is stored which is the power left after losses.

The OP asked to know how he could record what was put into the car, which would be total power.

It's akin to kVA Vs kW when taking reactance into account, what is the total power actually needed compared to what is actually usable at the end

Exactly ... and that's what post #7 covers.

siteguru said:

Exactly ... and that's what post #7 covers.

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But that isn't what you originally stated in post 4, which is where I said that doesn't take into account losses, and then in post 7 you added that you took it to be only what was stored is what you believed he meant and I said I'd take it to be the total power used as an electrical engineer.

And then I'm saying that there's a difference, as the OP asked for what was put into the MG4 not what was usable at the end.

All that tells us is that the initial query was vague enough to lead to different answers.