Real World Range

[TonyWilliams]

With my car approaching 18,000 miles, I'm starting to see the first signs of degradation.

With 151.9 miles driven plus about 12 GOM miles and 1 bar remaining, driving 50mph with climate control off created 4.1 miles per kWh, therefore I estimate that:

(151.9+12) / 4.1 = 40kWh available, down about 4.4% from 41.8kWh when new.

NOTE: I wouldn't normally make any kind of calculation with the GOM number, and I predict this 12 miles is slightly optimistic by a mile or three.

 

[ground_gainer]

Tony,

From your experience with the LEAF, is the battery degradation usually linear? I.e., should we expect to see 4.4% every 18,000 miles?

I wonder what the degradation of the RAV4 EV version 1 was?

Cheers

 

[snoltor]

down about 4.4% from 41.8kWh when new

Do you think or know if that's about what the Model S drivers are experiencing?

 

[TonyWilliams]

Tony,

From your experience with the LEAF, is the battery degradation usually linear? I.e., should we expect to see 4.4% every 18,000 miles?

I wonder what the degradation of the RAV4 EV version 1 was?

Cheers

No, not typically linear until the first drop, like I've had. I expect a smaller value from here forward.

 

[TonyWilliams]

down about 4.4% from 41.8kWh when new

Do you think or know if that's about what the Model S drivers are experiencing?

Well, they have active temperature control, and we don't (only when in READY and while charging). They will still have about the same I suppose, except for Rav4 EV's in the desert that are left in baking parking lots or garages while not charging or driving.

That's where the Tesla Model S will shine (as will the Volt).

 

[snoltor]

except for Rav4 EV's in the desert that are left in baking parking lots or garages while not charging or driving.

The garage at work where I charge is about 10 degrees cooler than outside, based on the car's thermometer. Question is, does the TMS shut off once the battery is finished charging? If not then I was thinking it'd be a good idea to charge and leave the car plugged in on the hottest days like we're having now (phone app predicts 109 today in Sac), whether or not I need the charge.

 

[TonyWilliams]

except for Rav4 EV's in the desert that are left in baking parking lots or garages while not charging or driving.

The garage at work where I charge is about 10 degrees cooler than outside, based on the car's thermometer. Question is, does the TMS shut off once the battery is finished charging? If not then I was thinking it'd be a good idea to charge and leave the car plugged in on the hottest days like we're having now (phone app predicts 109 today in Sac), whether or not I need the charge.

Apparently, it won't matter if it's plugged in. Only the actual charge will run the coolant pumps. A great project for somebody is a bypass to run the coolant over XX degrees and XX SOC%.

 

[snoltor]

Temp reaches max between 3 and 5 when I leave for home. So I guess I'll be starting the charge in the afternoon on the hottest days to make sure it's actively charging during peak temperatures whenever possible.

Only the actual charge will run the coolant pumps

 

[TonyWilliams]

Temp reaches max between 3 and 5 when I leave for home. So I guess I'll be starting the charge in the afternoon on the hottest days to make sure it's actively charging during peak temperatures whenever possible.

Only the actual charge will run the coolant pumps

I left the car in READY all afternoon (parked at hotel with fob inside and locked with mechanical key) with near 100F temps here in Grants Pass, OR.

In 8 hours, it used about 20 miles of range (and never went below 16 fuel bars from a 100% charge). I might not turn the car off again!

 

[ground_gainer]

Hmm, I really need to consider that on these hot Colorado days. It sits in the parking lots down there for 8 or 9 hours. There's a little shade but temps can easily be 90+ in the late afternoon.

My normal commute leaves me with 80+ miles on the GOM after my drive to work. I just need 25 or so to get home.

The other option is just to plug into one of the 110 outlets located near the lighting in the parking lot... but I don't really like calling attention to my car and I'm not sure if the building manager would get grumpy. Anyone else just plug in random places you find 110 outlets? The normal 110 charge time after my commute to work is between 8 and 8.5 hours though, so just about perfect for keeping things cool during the day.

 

[snoltor]

Trying this now

I left the car in READY all afternoon (parked at hotel with fob inside and locked with mechanical key) with near 100F temps here in Grants Pass, OR

 

[cjp767]

Here's a question for Tony, since he has seen a little battery degradation.

Tony mentioned that his extended charge capacity went from-- "40kWh available, down about 4.4% from 41.8kWh when new."

We understand the extended range will degrade, but what happens to the Standard Charge? Will the Tesla charging system keep the Standard Charge at 35 kWh until the total pack capacity decreases below 35 kWh? Or will the standard charge be held at 80% of the "new" full pack capacity?

 

[TonyWilliams]

Here's a question for Tony, since he has seen a little battery degradation.

Tony mentioned that his extended charge capacity went from-- "40kWh available, down about 4.4% from 41.8kWh when new."

We understand the extended range will degrade, but what happens to the Standard Charge? Will the Tesla charging system keep the Standard Charge at 35 kWh until the total pack capacity decreases below 35 kWh? Or will the standard charge be held at 80% of the "new" full pack capacity?

Great question, but unfortunately I can only give you my experience with the LEAF for the potential answer.

First, let me say that I don't find 35kWh available for a "normal" charge. About 33.5kWh. The 41.8kWh was rock solid for me, though. 80% of 41.8 is 33.5, so it makes sense.

The 80% charge is based on SOC, so as the battery degrades, that same 80% charge will be increasingly below 33.5kWh available.

 

[Ampster]

......... The 41.8kWh was rock solid for me, though. 80% of 41.8 is 33.5, so it makes sense.

The 80% charge is based on SOC, so as the battery degrades, that same 80% charge will be increasingly below 33.5kWh available.

Did you use some assumed miles/ Kwhr rate to calculate that number?

 

[TonyWilliams]

......... The 41.8kWh was rock solid for me, though. 80% of 41.8 is 33.5, so it makes sense.

The 80% charge is based on SOC, so as the battery degrades, that same 80% charge will be increasingly below 33.5kWh available.

Did you use some assumed miles/ Kwhr rate to calculate that number?

No, displayed data; the only readily available tool available.

 

[Ampster]

...........

Did you use some assumed miles/ Kwhr rate to calculate that number?

No, displayed data; the only readily available tool available.

Then my battery capacity has degraded to 41.02 in 9,000 miles and 9 months of ownership.

As a check on my math, I used displayed range of 105 after a normal charge, divided by the average 3.2 miles/Kwhrs displayed on the nav screen to get 32.81 Kwhrs capacity in normal. That number divided by .8 gave me my pack capacity.

I had forgotten that the average miles/Kwhrs was displayed on one of the nav panel screens. Thanks for the reminder. I had been looking at the entune app for those numbers but they are not the same.

 

[user 340]

I had forgotten that the average miles/Kwhrs was displayed on one of the nav panel screens. Thanks for the reminder. I had been looking at the entune app for those numbers but they are not the same.

Which screen are you using - is there a screen that shows the average mile/kWh since the last charge, not just for the last trip taken? The multi-information display (to the right of the speedometer / odometer) is great for showing the miles / kWh for the last trip right after you turn the car off, but I can't figure out how to measure the miles / kWh since the last charge. Can you do this on the Nav system by selecting EV / Energy Monitor / Past Record and resetting the record after every charge- or is there a better way?

 

[snoltor]

Can you do this on the Nav system by selecting EV / Energy Monitor / Past Record and resetting the record after every charge- or is there a better way?

That's the way I do it.

 

[TonyWilliams]

I use the center navigation screen:

1. Home button
2. EV
3. Energy Monitor

 

[ground_gainer]

Just tried the "lock the fob in with the key" trick. It's around 90 today. It's only burned off 3 miles in the last 3 hours so this may become the normal way to "park" at work during the summer. Thanks for the idea Tony! I figure protecting the temp of the battery will offer a long term benefit and I have about 60 or 70 miles to burn and still make my commute home.