Battery capacity reduction with time, idle time losses, uphill losses

Battery capacity reduction with time, idle time losses, uphill losses

I've had my Model S 60 for over 3 months and 5200 miles and am still loving it.

I'm aware there will be some degradation of the battery capacity over time. My use history is that I daily charge to 80 to 90% of capacity. It's only been charged to 100% on 3 or 4 occasions. (once at delivery)

I notice that my full charge rated range has dropped from 208 miles when delivered to only 198 today.

Is this typical?

Another interesting bit is that while on a trip I left the car unplugged in the garage for a week and the daily loss of charge was about 4-5 miles of range per day.

I've also found that a good rule of thumb is that a long up-hill trip in mountains will consume 3 miles of range for each mile traveled. (900 W*Hrs/mi) This means a 110 mile trip from San Diego to Lake Arrowhead in the San Bernardino mountains, with the last 10 miles all up-hill, will consume about 140 miles of rated range with normal driving.

cwmenne | 27 septembre 2013

Your first two sentences could have been written by me, exactly the same, just a month behind you, but my degradation isn't as bad as yours and I just complained to my SC about how much I've lost. A bit disappointed in the way they seemed to blow it off as "normal" and actually tried to blame it on software changes, until I told him that I haven't had a software update in the timeframe that I'm seeing the losses. When I first got it, an 80% charge would put me at 164 miles, but today, it's 159 miles. That's a lot to lose in 4500 miles and 2 months. I've only charged full twice and got 206 the first time, which dropped to 204 within 2 blocks. The second full charge only went to 204. Big disappointment if this is the rate of degradation I'm going to see going forward. I guess the good news is that at this rate, they will have to replace the battery under warranty, but the bad news is that I won't be able to dive the way I need to. I hope they figure this out soon!

Sudre_ | 27 septembre 2013

I've had my 60 since February and have over 9K miles on it. Max charged it several times and it still max charges to 208-210 miles. I am version 4.5.

Another bad thing is to drain it too much sometimes I wonder if that is worse than fully charging it.

I don't think your loss of range is typical. It may not even be permanent. It may also slow down once the battery is... burnt in. It is just hard to say. These particular battery packs have only been in service for less than a year... well they have been testing them longer but mass production...

Hopefully you don't continue to see the same losses.

jat | 27 septembre 2013

@cwmenne - change in range except at 100% charge *is* actually due to software changes. There are a number of threads on this already, but basically they created more margin below zero, so the range at other charge levels is reduced.

The only one that hasn't changed is the full charge immediately after it stops charging. If you wait, vampire losses will reduce it.

After 9600 miles and a half-dozen max-range charges, I get 264 rated miles on a max-range charge.

dtesla | 28 septembre 2013

Don't forget it may be what is reading the battery voltage that is not as accurate as before. My max charge is down to 250 after 11K miles. Recently, starting with a 250 mile of range, I went on a 280 miles trip at 65-70 mph (finished with 3 miles to spare). So I'm not sure what I think... battery, battery meter or software.

Also my drop also happened suddenly. At 9K miles I had a max range of 263. At 10K it was at 250. Today with 11K still at 250. But I did get a SW update between 9K and 10K miles.

mrrjm | 28 septembre 2013

I don't think you guys are seeing a loss in battery capacity. My Volt the range changes all the time. Several factors come into play... How the car has been driven the past few drives, temp outside, etc. I would imagine Tesla calculates the range somewhat the same.

jat | 28 septembre 2013

@mrrjm - unless you are looking at projected miles, the computation for rated range or ideal range is only dependent on the state of charge (and the software version, which defines that calculation).

sefischer1 | 29 septembre 2013

I've been on a 4.5 release since delivery. Initially the max trip rated range was 208 and repeatable after my first max charge.

Initially, I charged to 90% daily but about 4-5 weeks ago changed to 80% and started noticing the reported rated range dropping.

I just did the max charge and only received a rated range of 198 miles or about 5% below that I obtained when delivered 5.5K and 3 months ago.

diegoPasadena | 29 septembre 2013

As for your rule of thumb for the range loss during climbing, what matters more than the miles you drive uphill is how much elevation change occurs during the drive. If you subtract about 7 miles of range for every 1000 feet you climbed, all other metrics will remain surprisingly constant. That means, if traveling on a level freeway at 55 mph you get the EPA range, then you'd get the EPA range minus about 7 miles per 1000 feet elevation gain on an equivalent freeway drive, be it 5 miles or 50. I notice that factor pretty consistently even with a relative minor elevation change of about 700 feet, driving from Pasadena to Santa Monica.

riceuguy | 29 septembre 2013

As for "range loss" I find that an occasional "slow charge" at 110v seems to help re calibrate things. My range dropped after the 4.5 update, but after a couple of slow charges has returned to the full 208-209 miles, or 187 at 90%. Also to be sure to check your charge right as charging is complete as vampire drain (which mostly goes away in 5.0) can be pretty significant...if I look at the wrong time--after it has dropped but before the car decides to start charging again--I can be as low as 179 or 197 at 90% or 100%).

Roamer@AZ USA | 30 septembre 2013

My range goes down when my wife drives and goes up when I drive. Smart car. Try driving really efficiently and see if it goes back up.

Just charged my S85 to full for a longer trip and got a range of 314.

Mark K | 30 septembre 2013

This early on, range change is almost certainly driven by ongoing tweaks to the software algorithm, not actual battery decline.

Some anecdotal evidence -

We have two Model S cars. May 28 and September 7 delivery respectively. Rated range dropped about 10 miles on the first car after a software update. The second car settled in at the same level within days of delivery.

The first car has 5000 miles on it, and the second - 500 miles. Yet their range is now identical.

It is very hard to explain this as resulting from degradation of the packs's true internal capacity.

I think there is no material loss of capacity on either of our cars, just revised reporting of the numbers with a bigger safety margin.

Jolinar | 30 septembre 2013

+1 Mark K

my thoughts too.