Since I’ve added my Energica to my home assistant setup at home I got great insight in some of the numbers. One of them is the amount of energy that goes into charging the bike. My numbers will be per month but I’ll complete that with how much I ride so you can easily calculate that back to your situation if you wish so.

Energy lost

First of all let’s talk about losses. When you have a bike charging both the battery and the cable will heat up significantly. All this heat is wasted energy. So it’s easy to feel that there is energy lost. How much wasn’t very clear until now. I’ve often seen estimates of around 10%. Turns out that is pretty much accurate, in my case it looks like that’s even the minimum.

Sorry about the inconsistent naming, I know, I need to fix that. To get to these numbers I simply measure the amount of energy coming out of the socket with a Tapo P110 smart plug. The next number is calculated (hence the title of the card) from the Current and Voltage numbers logged directly from the bikes canbus messages. So that is what the battery really receives compaired to what is put into it.

This loss is created because of resistence in the cable but also the transformation from AC current (wall socket) to DC current (battery) which the charger on the bike does. It has a maximum output of 3 kW, I’m only using it at 1,8 kW to safe my wiring and sockets.

It might also be interesting to check if this loss changes based on the selected charger output. I’ve seen messages about higher losses on lower output. Never confirmed that though.

Total Amount of Energy used per month

For februari I’ve ridden only my route from home to work and back with the bike and only charged at home. This way I had a clear number without pollution from outdoor charging or riding for fun (imagine that :p). For this again it’s the tapo P110 wall plug that monitors this information.

If you continue reading here you’ll see I only ride 2 days a week. The reason there are more charges is because I charge back up to 80% once at home. Then let it sit that way to preserve battery lifde. And on the evening before work I charge to 100% again. Why it’s showing 24 hours on the X axis for a monthly overview? No clue.

And finally some details about my commute

Obviously these numbers are useless without some details on that commute of mine. I work 2 days from the office and I live around 54 km from work. So that is just over 100 km per day and around 200 km per week. In a month that would be 800 km in total. I’ve checked for this specific februari and discovered it was exactly 8 rides.

Furthermore I have a non highway but still pretty fast route to work. I go over almost exclusively 90 kph routes and rather keep a 100 kph pace where traffic and location permits.

In conclusion I used 99.494 Wh for 800 km so I consume ~124 Wh/km including charge losses (w/o it’s closer to 90 Wh/km). At home I pay 0,24 EUR/kWh (taxes excluded) so that is a cost of only 24 EUR per month.