I share a CEE outlet for charging EVs with my neighbour. (I can add that Iit has a 10 amp fuse and a B earth leakage circuit breaker, to avoid the comments saying “that’s dangerous”, because it’s not, and it’s all within Norwegian specs.) I can see the difference between the two cars because his only takes 1850 watts on the portable charger, while mine takes around 2100. So the charging usage can be split between above and below 1900 watts. Can I in any way calculate the kWh used on charging each car for a certain period.
The two sensors are named sensor.elbillader_electric_consumption_kwh and sensor.elbillader_electric_consumption_w.
A utility meter with two tariffs would work well here.
Set a u.meter off of the kwh sensor and give two tariffs name “car_lowpower” and “car_highpower” (or your preferred name).
Then I would make an automation with something like:
if consumption_w above 1900 for 1 minute, set tariff to car_highpower.
If consumption_w below 1900 for 1 minute, set tariff to car_lowpower.
You’ll get two output sensors, for the total kwh consumed by each car.
Do both vehicles charge with 1850W and 2100W respectively until they’re fully charged or is that reduced when the batteries are getting close to 100%?
If so, you probably cannot rely on the power that’s currently being used to set a sensor which car is being charged - you might have to trigger the sensor for that when charging starts (or a few minutes in).
I have tried to install Powercalc, but it doesn’t seem like that supports history before it was installed. I may be wrong, but if that’s the case it’s a problem. I need to get what has been charged the last month or so. I apologize for not making that clear in the first post.
Same thing with the other solutions, they don’t seem to support the history that’s before it was created.
And @chairstacker You don’t charge an EV 100 % except for right before a long trip if you want to keep the battery as long as possible. Between 20 and 80 % is the sweet spot. As for charging power that really doesn’t come into play with anything less than 50 KW charger, weaker chargers will charge with the same power until you stop them.
This seems to be a completely different approach than what happens with my Tesla Powerwall:
The Powerwall is charged back up to 100% every day (the warranty on unlimited cycles helps here not to cringe) in order to provide maximum backup capacity - and the last 3%-5% charge rather slowly with the bigger share being already sent to the grid before the battery is fully charged
There is research coming out that not using the batteries is worse than using the batteries. Also when you are at a Level 1 or Level 2 Charger it does not hurt the battery to go to 100%. It is fast charging that curtails the battery. And the research is also showing that the life is much longer than the mfg originally suggested. It’s why old leaf batteries have found a use on the grid to meet arbitrage.
@Chairstacker At least the Powerwall 3 has a different battery chemistry, called LFP, and that is no problem at all keeping at 100 %, apparently. The Powerwall 2 has NMC chemistry, but according to a few posts I found on Reddit. Like this one.
@AllHailJ Interesting! I have not seen that research about it being OK to charge fully. Do you have references, because I’d really like to see that! I have always been recommended to keep my Mercedes EQC between 20 and 80 %, and except for the occasional long trip (serious IBS has limited them the last few years) I have done that. As for fast charging (around 100 kw) I can probably count the number of times I have done that on my two hands and one foot. The wisdom the last few years has, as you stated, been that the rest of the car is shot before batteries, at least batteries from the last five years. An EQC taxi in Helsinki rolled quite far:
after two years and 234,518 km the battery capacity is 73.3 kWh. The initial usable capacity for the EQC is 80 kWh, so after all of that usage the battery only lost about 8.45% of its capacity. This comes after an estimated 585 charge cycles
That car was carged with a 40 kW charger, very little fast charging, so that supports the case against fast charging.
Edit: This blog post lays out the conventional wisdom pretty well. But again, I 'd love to see that new research.
I read about the first three statements I made in the Sustainability Times. The article came out about a month ago. I am sorry I do not have the citing. The use of old leaf batteries was in eco times.
Here is a good article on battery degradation. One of the primary causes of degradation is heat buildup during charging which is why fast charging does more damage to your battery than level 1 or level 2. There is also evidence from BYD that where you store your car - garage v outside can have an effect on how long your battery lasts.
I am still looking for the article I read. I would never presume to tell someone how to charge or look after their personal property. I am just relating my experieinces. I charge to 100% on level 1 and level 2 and have for the last 2 years and have seen no problems on my Rivian.
Heavy stuff! I read a few points and the conclusion, and I think I’m glad I live in Norway, not Arizona. I got the same takeaway from a few articles on Sustainability Times, but they did seem very fond of expressions as breakthrough, unimaginable, gamechanger and so on.
And you sure know how to make a guy feel small and jealous! Is that a pickup or a SUV Rivian you have? Very cool cars! They don’t import them to Norway, as far as I know, but we do have the Ford F-150 Lightning, which is quite the monster as well.
I don’t mean to even make anyone feel small or jealous, I apologize if I did. It is a 2023 Rivian R1T (pickup) and I think it is the best vehicle I have ever owned, although 800 hp is ridiculous. I agree, Sustainability Times can be exuberant at times - well, a lot. But they do report on interesting stuff that makes me research further. I live in Colorado, so not the hot weather of Az or the cold of Norway. Although the EU and Canada is looking better all the time, if not for children and grandchildren.
I did mean that as a joke, and it’s an icredibly cool car! My EQC has 400 hp, and five seconds 0-60 is good enough for me. Colorado sounds like good middle ground as a climate. As for the current affairs, I was actually close to writing that the Sustainability Times’ language reminded me a bit of spraytan man, but I didn’t know what side you were on, even if I did suspect it since you read a climate and tech magazine. Now I know. The right side of history.
Thanks for the tips.
I have always been recommended to keep my Mercedes EQC between 20 and 80 %, and except for the occasional long trip (serious IBS has limited them the last few years) I have done that. As for fast charging (around 100 kw) I can probably count the number of times I have done that on my two hands and one foot. 
I got the same takeaway from a few articles on Sustainability Times, but they did seem very fond of expressions as breakthrough, unimaginable, gamechanger and so on.