In theory kW consumption of the engine can be converted to Wh/mi by dividing by the speed in mi/hr then multiplying by 1000. Sounds great, but what if the kW number displayed on the dash is only the engine usage and doesn't include all the drain from the battery? I say this because I see periods of high consumption on the history graph which don't seem to be displayed in the kW thermometer bar. Nearly every time I start out I get higher power usage for some miles. On the highway it appears that occasionally I see unexplained high usage for a few miles.
I can't account for this by cabin heating. The heater isn't going to come on full blast for 5 minutes then shut off for half an hour. I can only imagine the thermostat has a much shorter duty cycle than that. But the battery heater may well have such a long cycle period. It's not really trying to keep the battery at a given temperature, it's trying to keep it in a range. So when it gets too low the heater comes on and the consumption goes up for a while as the rather large thermal mass of the battery warms up. 6 kW at 60 mph equates to 100 Wh/mi. Enough to show on the history graph even if it is not as much as I am seeing which is often jumps from 400 to 600 Wh/mi.
Anyone know if the battery would need warming while traveling at 60/70 mph?
I'll be going on another trip today. I'll keep a closer eye on this to see if it is just that I'm not noticing hills.
I can't account for this by cabin heating. The heater isn't going to come on full blast for 5 minutes then shut off for half an hour. I can only imagine the thermostat has a much shorter duty cycle than that. But the battery heater may well have such a long cycle period. It's not really trying to keep the battery at a given temperature, it's trying to keep it in a range. So when it gets too low the heater comes on and the consumption goes up for a while as the rather large thermal mass of the battery warms up. 6 kW at 60 mph equates to 100 Wh/mi. Enough to show on the history graph even if it is not as much as I am seeing which is often jumps from 400 to 600 Wh/mi.
Anyone know if the battery would need warming while traveling at 60/70 mph?
I'll be going on another trip today. I'll keep a closer eye on this to see if it is just that I'm not noticing hills.