Rather than pontificating, here are some
measurements.
My goal here was to get a sense, in bulk, of the steady state energy used while the car was just sitting overnight. So this should include losses from any vampire drain, battery warming, inefficiencies in the EVSE and charger, etc.
The energy tracker here is a
TP-Link HS110 smart plug. Third party checks call it out as being about +/- 5% accurate on the measurements. Which is sufficient in my book for a sanity check.
Conditions:
- Model 3, LR RWD, (Mftr: May '18)
- Parked in a garage for 1 week, no driving
- Garage temperature (approximately 6C (10am/10pm))
- Car set to charge to 80%
- Charging limited in car to 10A @125V
- Power turned on at the socket 7pm to 7am, off during the day.
- 2018.48.1
Total 7 day draw, including 3rd party EVSE: 10.4 kWh
So, at Toronto Hydro overnight rates, that's about $ 0.676 per week, or about $12 for the winter.
So from a cost perspective I'm giving this a massive <shrug>
Of more interest to me is the question of whether lots of small charges is better or worse than infrequent top-ups along with cold temps.
ymmv. Or should that be ykWhmv ?