Rated range loss after 1 year

[glhs272]

I've got a 2013 60kWh Model S and my vin is in the 5000's. I hit 42,000 miles this week and my battery charged t0 209 rated miles this week, although that was the first time that I've seen it hit 209 on a full charge.

I'm really in need of a 85kWh battery since my commuting miles have significantly increased since receiving the car in March 2013, so it's very likely that I'm going to start doing a 100% range charge everyday from now on. I've got my fingers crossed that Tesla will offer a battery upgrade when the gigafactory is complete.

I take it you have been consistently charging to 90% or greater? At 42,000 miles and no detectable range loss, I would say that is pretty good. I am at 206 rated miles at 35K miles. I only lost range when I started doing the sub 90% charging. I got most but not all of it back after I stopped doing that. But 206 is only about 1% range loss after 1.5 years and 35K miles, so I am happy. I try to charge twice daily (once at work, once at home) after about 35 miles each way.

 

[TexasEV]

I take it you have been consistently charging to 90% or greater? At 42,000 miles and no detectable range loss, I would say that is pretty good. I am at 206 rated miles at 35K miles. I only lost range when I started doing the sub 90% charging. I got most but not all of it back after I stopped doing that. But 206 is only about 1% range loss after 1.5 years and 35K miles, so I am happy. I try to charge twice daily (once at work, once at home) after about 35 miles each way.

I don't think you "lost range" and "got it back". It's just the car reporting the estimated range more or less accurately.

 

[glhs272]

I'd be very happy with that! You live in a hot climate too, so that says more than owners in cooler climates. It's been very hot in my garage this summer; well over 100 degrees many days/weeks and I've been reluctant to charge to high state of charge. That obviously didn't work or matter.

I just called the service center and the guy told my 10% loss in the first year is expected. Seems that some of you have not experienced this 10% loss ...



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Just curious about how low your state of charge is before you recharge.

I don't drive big distances hence the low miles on my car (with no use of the car due to travel for longish time periods). The guy I just spoke with said I should let the battery get low once in a while and then charge.

I think they recommended running it to a low sate of charge once in a while to reset the battery capacity calculation. Usually I am at about 70% SOC before I start charging again. I am thinking that keeping the depth of charge as small as possible helps. But ImperialG is seeing no capacity loss when doing full depth of charge cycles has me wondering.

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I don't think you "lost range" and "got it back". It's just the car reporting the estimated range more or less accurately.

Yeah I suspect is was getting out of balance which does give actual loss of range, but not degradation per say. But the broader point is sub 90% charging = bad.

I would say Tesla saying that 10% capacity loss in the first year is setting the bar really low.

 

[mai]

bwilliams, a couple things can artificially reduce the estimated range (beyond normal degradation) - an out of balance battery and an uncalibrated SoC estimate. Daily charging to 60% will likely bring your battery out of balance. The going theory in the Decreasing Rated Range thread is that the the battery only rebalances when the voltage difference between the strongest cell and weakest cell exceeds some threshold, but at lower SoC levels, the voltage differences are muted. Also, the battery teardown thread revealed only low power rebalancing circuitry, so out-of balance cells will take a long time to rebalance. That's why you should at least occasionally let the car sit at higher SoC level (90%-100%). Charging to 90% daily will minimize the amount of rebalancing needed and will get you some range back.
The range estimate may also need calibration if you don't drive your car from a high SoC to a low SoC once in a while - it can only guess at how the battery voltage will drop as it discharges in use. Driving the car from a high SoC a low SoC will give it more data to give a better estimate as to when it will reach "0" miles (I think this explains why some people can drive their car many miles after the car says 0 miles left, but others cannot).

 

[bwilliams]

Interesting. I only drove the car one time to low soc - and I was sweating it with range anxiety. So, I've only charged it one time to 100% and only 1 time driven to low soc. Both were in the last couple of weeks. I just cringe to think about charging the car when my garage is so hot but my information is probably not correct. I don't doubt that heat is bad (I own a LEAF and have heard plenty of nightmarish stories from LEAF owners who live in hot areas) - that might be where my concern lies. It is supposed to cool down here in San Diego County next week so I'll try the 90% charging then try a full charge again in a couple weeks.

bwilliams, a couple things can artificially reduce the estimated range (beyond normal degradation) - an out of balance battery and an uncalibrated SoC estimate. Daily charging to 60% will likely bring your battery out of balance. The going theory in the Decreasing Rated Range thread is that the the battery only rebalances when the voltage difference between the strongest cell and weakest cell exceeds some threshold, but at lower SoC levels, the voltage differences are muted. Also, the battery teardown thread revealed only low power rebalancing circuitry, so out-of balance cells will take a long time to rebalance. That's why you should at least occasionally let the car sit at higher SoC level (90%-100%). Charging to 90% daily will minimize the amount of rebalancing needed and will get you some range back.
The range estimate may also need calibration if you don't drive your car from a high SoC to a low SoC once in a while - it can only guess at how the battery voltage will drop as it discharges in use. Driving the car from a high SoC a low SoC will give it more data to give a better estimate as to when it will reach "0" miles (I think this explains why some people can drive their car many miles after the car says 0 miles left, but others cannot).

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Maybe setting lower expectations. ?

I would say Tesla saying that 10% capacity loss in the first year is setting the bar really low.

 

[Xenoilphobe]

I HPWC (80 AMPS) charge daily to 80% and when new the car would full charge to 264. I never "range" charge. The car at full charge gets 259 miles at 100% charge with >25,000 miles in 11 months of driving. I am ok with this and suspect if I changed to range charge and did another change it would go higher, but frankly I don't need the additional range for my commute.

I have noticed that when i charge with 120v 15AMP (work wall outlet) it seems to lose range faster (not sure if this my uphill commute home from the Potomac River).. but I am sure this plays a role. I don't do that anymore as it is not necessary, and I charge with solar at home, so there is no cost benefit.

 

[jerry33]

Interesting. I only drove the car one time to low soc - and I was sweating it with range anxiety. So, I've only charged it one time to 100% and only 1 time driven to low soc. Both were in the last couple of weeks. I just cringe to think about charging the car when my garage is so hot but my information is probably not correct. I don't doubt that heat is bad (I own a LEAF and have heard plenty of nightmarish stories from LEAF owners who live in hot areas) - that might be where my concern lies. It is supposed to cool down here in San Diego County next week so I'll try the 90% charging then try a full charge again in a couple weeks.

As you probably know, the Leaf doesn't have any active thermal management, so it's not really applicable to the Tesla. The Roadster batteries show a totally random pattern when compared to geographic location (there's a graph in one of the threads), so heat isn't a factor.

 

[bwilliams]

Yes, I realize the tesla has thermal management. I guess that didn't quell the concern about charging in a very hot garage.

I wonder if Tesla is monitoring and data collecting each of us. I'd like to see the data.

As you probably know, the Leaf doesn't have any active thermal management, so it's not really applicable to the Tesla. The Roadster batteries show a totally random pattern when compared to geographic location (there's a graph in one of the threads), so heat isn't a factor.

 

[Rodolfo Paiz]

But the broader point is sub 90% charging = bad.

Maybe, though my own data point does not fit that hypothesis. My P85 is 1y7m old, with under 11,000 miles. Since I drive very little, I charge to 72% and then plug in when I see 40% or so. The lowest I've seen in many moons was 75 rated miles left when I plugged in. About 6 times a year, I range-charge to get from Miami to Orlando. A few months ago, a 100% charge was giving me 255 rated miles. But today's range charge yielded 262. Go figure.

 

[jerry33]

Yes, I realize the tesla has thermal management. I guess that didn't quell the concern about charging in a very hot garage.

I wonder if Tesla is monitoring and data collecting each of us. I'd like to see the data.

Yes, they collect the data. This is known because if you call in with a problem, the first thing they do is inspect the logs (also you sign a release when you purchase the car to allow them to do so).

As far as the hot garage goes: When it's charging do you hear the fan and a/c going? (It's loud and hard to miss.) Also always charge with range mode off so that the maximum active cooling (heating in the winter) will take place.

 

[bwilliams]

I've never ventured into the garage at midnight (3 hours past my bedtime and when the cheaper electric rate begins). I trust the thing is working correctly as far as cooling. I'll try a charge during the day to make sure ...

This is the subject of another thread, probably, but what IS going on when I go out to the garage, car NOT charging, but humming away. It's like living with Hal. I'm assuming Tesla is doing something - and this happens far more than when the car is updating software.

Yes, they collect the data. This is known because if you call in with a problem, the first thing they do is inspect the logs (also you sign a release when you purchase the car to allow them to do so).

As far as the hot garage goes: When it's charging do you hear the fan and a/c going? (It's loud and hard to miss.) Also always charge with range mode off so that the maximum active cooling (heating in the winter) will take place.

 

[jerry33]

This is the subject of another thread, probably, but what IS going on when I go out to the garage, car NOT charging, but humming away. It's like living with Hal. I'm assuming Tesla is doing something - and this happens far more than when the car is updating software.

I doubt Tesla is doing anything, but there are a number of things the car could be doing on it's own, such as cooling the batteries or charging the 12V battery.

 

[bwilliams]

Thanks for the info. I'm sure you're right; especially given the temps here this summer.

I doubt Tesla is doing anything, but there are a number of things the car could be doing on it's own, such as cooling the batteries or charging the 12V battery.

 

[F8L]

Thanks for the info. I'm sure you're right; especially given the temps here this summer.

It's pretty safe to assume. My Volt does this quite often and even my Plug In Prius used to do it. Garage temps here can get well over 110F.

 

[AmpedRealtor]

Yes, I realize the tesla has thermal management. I guess that didn't quell the concern about charging in a very hot garage.

I wonder if Tesla is monitoring and data collecting each of us. I'd like to see the data.

If you charge overnight, then time is not an issue. To address your concern, turn down the charging power.

 

[islandbayy]

If you charge overnight, then time is not an issue. To address your concern, turn down the charging power.

Along with that, I have found since I stopped charging at full 40 amps every night, I also stopped eating up UMC's. I think they couldn't handle the heat build up day after day. Current UMC is going strong. Usually 30 amps or less. Only if I need range as quick as possible do I use 40 amps now.

 

[AmpedRealtor]

Along with that, I have found since I stopped charging at full 40 amps every night, I also stopped eating up UMC's. I think they couldn't handle the heat build up day after day. Current UMC is going strong. Usually 30 amps or less. Only if I need range as quick as possible do I use 40 amps now.

I have had a similar experience with the HPWC. The first year I charged at the full 80A and required two charge cord/handle replacements due to fault. I now keep the HPWC at 60A or less and have not had any issues so far. Everything runs cooler and car does not ramp up its fans when charging under 60A.

 

[jerry33]

Along with that, I have found since I stopped charging at full 40 amps every night, I also stopped eating up UMC's. I think they couldn't handle the heat build up day after day. Current UMC is going strong. Usually 30 amps or less. Only if I need range as quick as possible do I use 40 amps now.

Right. I normally charge at 32/33 amos. I did have an interesting experience on my vacation a couple of weeks ago. Another Tesla owner and I pulled into the RV park at the Winfield, KS fairgrounds at close to the same time. We had both charged at Salina.

- We both set the charge rate to 32 amps.
- The 14-50s were out of the same service panel.
- His car was only a few weeks old, mine is 20 months old.
- I have the new UMC adapter.

His UMC adapter was ice cold after 90 minutes of charging, mine was warm--not overly warm but the difference was striking.

 

[freds]

4. Batteries have less capacity in cold weather.

Hmmm, so we can see our rated capacity go up and down based on the time of the year?

 

[TES-E]

I also charge at 60 amps. Everything stays nice and cool. Charges at 45 mph at that setting.