veimi wrote: DBMandrake wrote:
The power meter on the dashboard measures power, not current as far as I know. Where did you get the information that it measures current ?
5kW is enough to drive at a constant 30mph, and the needle will be much higher when driving at 30mph with the heater off than with the car stationary and the heater on full. (and before warmup) The needle hardly moves out of the gap on mine with the heater on full.
I've always assumed that the power meter tries to subtract the power drawn by the heater and does it inaccurately, or that the meter reading is non-linear. If you compare the meter reading to the power drawn reported by Canion it does seem to be quite non-linear however it's difficult to plot it accurately while driving...
Just some comments and my observations.
If one can assume that the battery voltage is relatively constant wouldn't that mean that there would be little difference between measuring current or power?
If the battery voltage were constant yes, but it isn't. It varies a lot with changes in load and regeneration. It's pretty normal for the voltage to drop 20 even 30 volts under full acceleration vs coasting and to rise at least 10 volts during regeneration, so there are large swings in response to current out/in of the battery, and therefore an ammeter would be misleading.
Also we have no reason to assume it isn't Power - it even says "Power" right on the meter...
Ultimately it's power that gives your acceleration (or generates heat in the heater) so that's what matters.
Sitting in my driveway in a cold environment with the heater and fan turned on max, the needle on my car is halfway between the start of the green and the start of the letter E in ECO.
This position of the needle corresponds approximately to its position when the car is being driven at 35 kph (21 mph) on level ground with the heater and fan off.
Mine barely goes into the green - this was taken with the heater on full blast and Canion reporting a consumption of about 5kW from the heater:
If I drive at 30mph with the heater off Canion also reports about 5kW of consumption, but now the meter is somewhere within the word Eco.
So at least on my car the heater usage is dramatically under reported by the power meter on the dashboard. Not sure why and whether that's on purpose or accidental. It's something I noticed soon after I started using Canion but didn't think much of it.
Another thing that's a bit suspicious about the power/regen meter is that judging by the presented scale, maximum regeneration is only 1/3rd of maximum acceleration in terms of power, but that's not true. Maximum power (before motor losses etc) is around 55kW while maximum regeneration is around 25-30kW so about half of maximum acceleration.
So either the meter is non-linear or the regen side of the scale cuts off prematurely when more regen is still available. (Probably the latter)
I wouldn't treat the power/regen meter on the dashboard as gospel, I think it takes some liberties in its presentation and should only be considered a relative meter.