Big temperature effect on range / efficiency??

[miimura]

The RAV4 EV instrument panel range estimate is always based on your recent driving efficiency. The "Ideal Range" on the Roadster and "Rated Range" on the Model S are always directly proportional to the battery's current energy stored by a fixed constant selected by Tesla. This is a reliable indicator of SOC. We don't have that on the RAV4 EV. It may be available on the Tesla OBD connector at the back of the car, but as far as I know it's not been revealed how to get at that data. This is the point of the GIDmeter that Tony was trying to get working for the RAV4 EV.

 

[Ampster]

The question is, what meaningful data can we give them that they could track? I don't know of a way to get the car to report the amount of energy stored in the battery. We have no "Rated Range" or equivalent that is always proportional to the stored energy by a fixed constant. Please prove me wrong. I would like to follow that for myself.

I agree we don't have a number for storage capacity but in another thread didn't Tony show us that we can divide miles shown on the GOM by the Avg of miles per 1Kwhr to calculate Kwhr capacity of the pack. I did that one time and calculated my pack had 32.8Kwhr.

 

[snoltor]

I agree we don't have a number for storage capacity but in another thread didn't Tony show us that we can divide miles shown on the GOM by the Avg of miles per 1Kwhr to calculate Kwhr capacity of the pack. I did that one time and calculated my pack had 32.8Kwhr.

His estimate was in the "Real World Range" discussion.

 

[TonyWilliams]

The question is, what meaningful data can we give them that they could track? I don't know of a way to get the car to report the amount of energy stored in the battery. We have no "Rated Range" or equivalent that is always proportional to the stored energy by a fixed constant. Please prove me wrong. I would like to follow that for myself.

I agree we don't have a number for storage capacity but in another thread didn't Tony show us that we can divide miles shown on the GOM by the Avg of miles per 1Kwhr to calculate Kwhr capacity of the pack. I did that one time and calculated my pack had 32.8Kwhr.

I really don't use the GOM for much... but, you can drive the car from a known threshold (100% or 80% charge) and drive to turtle.

The observe the odometer and miles/kWh from the navigation screen. These both needed to be reset prior to driving.

If you drove 146 miles, and the economy was 3.5 miles per kWh, then the usable kWh is simply 146 / 3.5 = 41.8kWh.

By the way, this is the default economy. I'm down to about 40kWh usable, but not too bad considering that the battery is NOT actively cooled and I have 18,000 miles.

 

[snoltor]

Tony or others, quick question: at what point does the car go into turtle mode? Maybe that's been posted that elsewhere, but I searched the forum through Google and didn't find it. Can turtle mode be predicted by the GOM miles left? Yesterday was the lowest I've taken the battery so far, first time I got a low battery warning while driving. GOM estimating 16 miles left when I plugged in.

I really don't use the GOM for much... but, you can drive the car from a known threshold (100% or 80% charge) and drive to turtle.

 

[user 340]

Tony or others, quick question: at what point does the car go into turtle mode? Maybe that's been posted that elsewhere, but I searched the forum through Google and didn't find it. Can turtle mode be predicted by the GOM miles left? Yesterday was the lowest I've taken the battery so far, first time I got a low battery warning while driving. GOM estimating 16 miles left when I plugged in.

I got the low battery warning once with about 16 miles on the GOM, but another time I had 19 miles but did not get the warning. I did notice that I had only 2 bars lit on the state of charge bar graph to the left of the GOM when I got the warning and 3 when I did not. Perhaps the less precise SOC bar graph is more accurate than the GOM for estimating remaining charge.

I'm also curious as to when turtle mode kicks in - I haven't experienced that yet.

 

[TonyWilliams]

Low battery - 2 fuel bars illuminated
Very Low - 1 fuel bar
Climate Control Limited - 0 fuel bars

Turtle - when lowest cell hits its low voltage threshold, so turtle can come on with 1 fuel bar or zero fuel bars.

First, I expect the GOM to show "LO" before turtle.

 

[snoltor]

Low battery - 2 fuel bars illuminated
Very Low - 1 fuel bar
Climate Control Limited - 0 fuel bars

Turtle - when lowest cell hits its low voltage threshold, so turtle can come on with 1 fuel bar or zero fuel bars.

First, I expect the GOM to show "LO" before turtle.

Thanks.

 

[mhkp]

Is there a correlation to range degradation with increased passanger weight? I.e. 1 vs 5 passengers?

 

[TonyWilliams]

Is there a correlation to range degradation with increased passanger weight? I.e. 1 vs 5 passengers?

Yes and almost no. For going up and down hills, absolutely. For in town stop and go, of course. For steady speed on level highway, not so much.

Your car at 4032 pounds plus a 168 pound driver (4200 pounds gross) to be lifted 1000 feet equals 4,200,000 foot/pounds, or 1.58kWh of energy.

The same car with five 200 pound guys is 5,032,000 foot/pounds of energy to increase 1000 feet, or 1.895 kWh to do the same job.

 

[jspearman]

So a little anecdotal evidence about heat and range loss. Somewhere around 110 degrees the range drops down to around 98-100 miles on an 80% charge (it's around 90 deg at night). Now that we have been in the low 100's for a few days the GOM shows around 115 miles, which is roughly what we had in the cooler spring (current nightly lows are in low 80's). The GOM has always been quite accurate for us.

By comparison, the Leaf had lost over 15% capacity at this point last year. Needless to say, I'm elated/relieved.