I am reporting this mostly for the benefit of the sense team, assuming someone is reading this…
So my Tesla MY has been recognized now and I’ve done two charging sessions since. In both sessions during most of it, it reported a max of 9,618W, which corresponds, to a T, with 240V @ 40A. Thing is, I have a 48A charger and actual use is 48A @ 227.65V (avg) or 10,972 W. Somebody suggested sense does not make assumptions, but the 9,618 number is suspiciously like an assumption and it happened twice now.
The first charge session worked more or less correct in the sense of detecting ramp-up and end of session and, were it not for the incorrect power, reported a wrong (but consistent) overall power use.
The second session was different. It reported the same power, but while (in both cases) the first session did, the second session does not report an “off” notification, but looking at the power meter graph, I can see it thinks shut-off was at 03:25AM, which is incorrect. See the two tables below for comparison:
Charging table: actual (directly from car)
|Start||End||Duration||kWh||Avg A||Avg V|
Charging table: from sense
Further inspection of the overall power meter shows a “data gap” from 3:27:00 to 3:27:12 where there is no data whatsoever. In the car specific graph it stops at 3:25:51. While I am convinced that data gap is what caused the “false” end of charging detection, it is strange that the timelines do not line up.
Overall the power mismatch causes about 1 kW/h to be attributed to “other” rather than the car.
So the issues seem to be:
- Assumption about max power use that is incorrect, but identical in both sessions
- End of charging not notified in second session, in the sense that no end notification exists, but power meter shows when it thinks it happened and reported consumption is consistent with that time
- Consequently a very large contribution counted as “Other” in the second session
- Timelines for overall and device specific shut-off do not align (difference of about 2 minutes)
- Data gap is apparently interpreted as power consumption dropping to zero. I would argue that, at least for short drops, a better assumption is a linear interpolation between last before and first data point after the gap. This would then have avoided the incorrect detection of end of charging
- Mismatch between some part of sense thinking charging ended (because power graph goes to 0 and kWh build ends there), and on/off notification system where there was no “off” notification