Charging energy consumption

[zsgugli]

Hi all,

Where can I check how much energy the car has charged in the current charging session?

I was unable to find this information in the car's infotainment system neither on the phone app.
They both show only % values and estimated range in miles.

The charger I usually use shows how much it charged, but when I use a different charger, I cannot get this info unless I do a little calculation for an estimate.

 

[ukslim]

As far as I'm aware, this isn't available.

It's definitely annoying. For example, a couple of weeks ago I was in an AirBnB that had an outdoor 13A socket. Actually I didn't notice until the day we left, so I didn't use it. But if I'd noticed it earlier, I'd have asked the hosts' permission, and offered to pay them 35p/kWh. But the car/app won't tell me how many kWh it added in the last (or current) charge.

I guess the only ways to get a rough kWh count is to note the %SOC before and after charging, and do some maths based on battery capacity. Or look at the charging power once it's charging, and calculate it based on time.

 

[siteguru]

Charging power fluctuates during a charging session, so using the rate is the most inaccurate method. Closest (as you say) is to use ( Finish SoC% - Start SoC% ) x usable battery capacity.

For the Trophy that would be (example) 80% - 20% = 60% x 61.7kWh = 37.02kWh.

That's what's gone into the car ... the charging session should be available in the charge point app (or on the charger itself if using a DC rapid).

( Car kWh / Charge Point kWh ) x 100% gives the charging efficiency.

 

[Kithmo]

With Pod point chargers it's shown on the Pod point app.
I would think it should be on other chargers' apps so they can show how much you've used and what it cost.

 

[ukslim]

Charging power fluctuates during a charging session, so using the rate is the most inaccurate method. Closest (as you say) is to use ( Finish SoC% - Start SoC% ) x usable battery capacity.

For the Trophy that would be (example) 80% - 20% = 60% x 61.7kWh = 37.02kWh.

That's what's gone into the car ... the charging session should be available in the charge point app (or on the charger itself if using a DC rapid).

( Car kWh / Charge Point kWh ) x 100% gives the charging efficiency.

Yeah, but that's no use if you've charged from a dumb charger, a 13A or a Commando socket.

I suspect that the charging power from a granny charger is pretty consistent, while the battery is actually charging (then drops for balancing if you leave it plugged in). Faster chargers deliver fluctuating power for all sorts of reasons, only some of which I'm clever enough to understand

 

[Martinonline]

I have a power meter for use with my granny charger where I have to pay someone for use if their electricity. Not yet required but tested at home to see differences between supplied power and reported power.

 

[ukslim]

I have a power meter for use with my granny charger where I have to pay someone for use if their electricity. Not yet required but tested at home to see differences between supplied power and reported power.

That's a good point. I bought a plug-in energy monitor from the Middle of Lidl, and it would probably do the trick. Slight concerns about pushing >2kW through it for long periods, but it's what it's specced for ?‍ .

 

[zsgugli]

Charging power fluctuates during a charging session, so using the rate is the most inaccurate method. Closest (as you say) is to use ( Finish SoC% - Start SoC% ) x usable battery capacity.

For the Trophy that would be (example) 80% - 20% = 60% x 61.7kWh = 37.02kWh.

That's what's gone into the car ... the charging session should be available in the charge point app (or on the charger itself if using a DC rapid).

( Car kWh / Charge Point kWh ) x 100% gives the charging efficiency.

Are you sure we are meant to multiply by the usable battery capacity and not the nominal one?

I have the extended range with 77kWh.

With Pod point chargers it's shown on the Pod point app.
I would think it should be on other chargers' apps so they can show how much you've used and what it cost.

I usually don't use any apps for charging. Just plug in and charge.

 

[fnegroni]

@Martinonline I’d find that power meter useful too. Do you mind me asking which one that is?

 

[Tight Git]

I used a Tapo P110 smart plug with my granny charger for a while which worked well - £10 on Amazon.

 

[Martinonline]

@fnegroni, I have an energenie device. I attach a picture of it in my waterproof box used for charging.

 

[JonnyG]

I used a Tapo P110 smart plug with my granny charger for a while which worked well - £10 on Amazon.

Yes,, me too ... very useful as all the info is available on the TAPO app including graphs and monthly totals. No hub or anything extra required either.... just the App.

Just make sure it's the P110 as you say which is described as "Tapo Smart Plug with Energy Monitoring" as there is a lesser model (the P100) which does'nt have the Energy monitoring.

 

[siteguru]

Currently shows as £9.99 for me with Prime:

https://www.amazon.co.uk/TP-Link-Tapo-Monitoring-Required-P110/dp/B097YBXHTW/

Something to consider.

 

[ukslim]

I guess those smart ones have to be paired with a WiFi network, which would cause frustration if you're using it when charging at someone else's property.

I was just considering putting my non-smart one (similar to this - https://www.amazon.co.uk/Electricity-Besvic-Monitoring-Consumption-Protection/dp/B0B3MQ6V86/ ) in the car in case it comes in handy. Then I remembered that the one time I've considered granny-charging on someone else's property, it was an outdoor socket in the pouring rain...

 

[fnegroni]

Yes,, me too ... very useful as all the info is available on the TAPO app including graphs and monthly totals. No hub or anything extra required either.... just the App.

Just make sure it's the P110 as you say which is described as "Tapo Smart Plug with Energy Monitoring" as there is a lesser model (the P100) which does'nt have the Energy monitoring.

I’ve ordered it. I’m just not sure how strong the WiFi is in my garage.
Of the device loses connection, does it store the energy consumption until the next time it reconnects?
I’m considering innr as an alternative or simply buy a WiFi extender

 

[jpk]

I’ve ordered it. I’m just not sure how strong the WiFi is in my garage.
Of the device loses connection, does it store the energy consumption until the next time it reconnects?
I’m considering innr as an alternative or simply buy a WiFi extender

If you have a dual band router use the 2.4GHz band for it as it's more stable over longer distances and better at penetrating walls

 

[JonnyG]

I have a WiFi extender quite close so not had any issues, but you raise a good point.

 

[lsb777]

I supposed a quick phone screenshot of the app (% soc & estimated range screen) taken before as a point of reference then a quick calc of: Usable battery figure multiplied by how many extra % achieved would give you the approx answer in kWh.

 

[siteguru]

With the granny lead I just assume 80% efficiency as that will be there or thereabouts. So kWh into car / 0.8 = kWh used from the supply (so you can reimburse your host for letting you use their supply).

 

[Waterstoney]

I used Kasa energy monitor to measure/control granny charger. Charger was typically consuming 2.4 kW while car was taking 2kW. My ZS LR could be toppped up 3% every hour. My house voltage was 245v when charging.

Now I am using Ohme ePod charger for. I noticed charger continued charging for about 30 minutes at 4kW after reach 100% SoC. About 2kWh was used without increasing range prediction.