Usage-meter, something's missing

[Trykpaa]

I had a 86% trip over Christmas which made me aware of the significance of a perculiar 'feature' or 'bug'.

Started preheated with 90%. Went carefully 60km => 60% left, usage acc board computer 145wh/km.
Before return trip, I preheated. When I left, battery was 57%, but average consumption unaffected 145wh. Faster route home 208wh/km => 4%.

Total usage according board computer 22,2kWh /86% = 25,8kWh. I still use equivalent to 30kWh to charge 100%. Something is missing. The 1kWh used during preheating, for sure. And then some.

The board computer cannot be trusted to be accurate. A German magazine compared charging losses on different EV and got very different values (10-25%). I bet board computer s are off on purpose to pretend better efficiency. Some sort of notching. Like on my diesel Civic.

[Left4Cookies]

I look forward to a compatible OBD tool/app which should hopefully give access to the real numbers instead of the current computer which seems pretty poor at estimating range and consumption (I don’t know, this is my first EV).

[londiniumperson]

I had a 86% trip over Christmas which made me aware of the significance of a perculiar 'feature' or 'bug'.

Started preheated with 90%. Went carefully 60km => 60% left, usage acc board computer 145wh/km.
Before return trip, I preheated. When I left, battery was 57%, but average consumption unaffected 145wh. Faster route home 208wh/km => 4%.

Total usage according board computer 22,2kWh /86% = 25,8kWh. I still use equivalent to 30kWh to charge 100%. Something is missing. The 1kWh used during preheating, for sure. And then some.

The board computer cannot be trusted to be accurate. A German magazine compared charging losses on different EV and got very different values (10-25%). I bet board computer s are off on purpose to pretend better efficiency. Some sort of notching. Like on my diesel Civic.

I'm very confused as to where your figures came from, please can you explain in more detail.
I'm particularly interested in where you're getting the 22,2kWh over your 86% usage, because I'm sure this information isn't available on my UK 'e'.
Also when you preheated, was this whilst plugged in and was the % value that you've stated before or after the preheating?
Finally, for now anyway, where are you getting the amount of power (30kWh) that you're using to charge to 100%?

[Trykpaa]

The 22,2kWh is distance traveled x consumption acc board computer. 30kWh from the home charger. I only charge at home.

[londiniumperson]

The 22,2kWh is distance traveled x consumption acc board computer. 30kWh from the home charger. I only charge at home.

OK, I think that I now understand.
As you've observed, the preheating is not included in the calculations, therefore as you always charge from home then this must be from the battery itself. The heater uses about 3kW not 1kW, so that's one thing missing from your calculations, also again as you've stated, there are loses in the charge process, typically 20%, so your 30kW is only about 25kW stored in the battery.
Try updating your calculations (in reality estimations because there are several unknowns/guesstimates).

I'm also very confused over your stated efficiency, you quote 145wh/km on both the out & return journey, which is very odd, mine varies wildly.
Getting back to the 145wh/km value that seems very efficient compared to my experience.
I make 145wh/km as 6.9km/kWh which in turn is 4.3m/kWh. Over the 2670 miles I have been getting between 1.4 & 4.1m/kWh (444wh/km & 152wh/km respectively) with 2.9m/kWh average (I have kept a spreadsheet of every single day's charge/odometer/efficiency since purchase), so the 145wh/km (4.3m/kWh) is amazing because I have never got that efficiency no matter how slow I've driven, I'm currently happy/surprised to get above 3m/kWh (207wh/km).

I made an error in my initial posting, so updated this post:
6.9k/kWh=180km for 100% charge, therefore 60km travelled is approx 30% of 180km and aligns with what you are seeing on the Honda.

[Trykpaa]

The heater uses about 3kW not 1kW, so that's one thing missing from your calculations, also again as you've stated, there are loses in the charge process, typically 20%, so your 30kW

I wrote about consumption, not power. 3% battery ~ 1kWh.
20% charging loss is way too high. I had 9,5% charging loss over the first 5000km (calculated board computer / charger readout). I know that some makes e.g. Tesla measure up to 25% charging loss but I bet it is camouflaged lack of efficiency. Similar to what the I experienced with the e on said trip.

[ChesterUK]

Checking my IHD (In Home Display for the house electricity smart meter), I noticed that our Zappi maxed out for about 4-5 minutes at >7kW during pre-conditioning, and then started to reduce gradually to about 2kW, and then reduced further a little. It's definitely worth leaving it plugged in if you want maximum range in the cold.

On the energy consumption, I've noticed the figures for the trip computer and the power flow meter at odds with each other. Power flow includes everything, but the trip only seems to include energy consumed for propulsion. That's a bit disingenuous. MPG in an ICE incorporates energy required/generated for all systems, so it should in a BEV.