Jan 19, 2015
jerry33 It's perfectly normal balancing. It's actually easier to see it happening at a Supercharger where at the end you'll see the amps cycle through the low numbers 9-8, 8-7, etc.�
Jan 19, 2015
Klaus Didn't you report before that you have lost significant max range?
This process is exactly what will help regain those "lost" miles. On my 60 I recovered 5-6 miles (estimated) 90% range during a recent trip with multiple nearly full Supercharges, and discharging into the 20s to 40s miles several times. When you need a range charge, let it finish at least 1 1/2 hours before you leave so it can go through its entire "balancing act". Doing this a few times seems to be even more effective. I wouldn't do it without needing the range charge though, to avoid the penalty of long-term battery degradation.
According to the thread about disassembling and the guts of the battery, it seems that balancing bleeds off higher voltage cells into resistors, and the battery AC probably removes that heat. Drawing a few kW during balancing probably reflects that.
(Just my personal conclusions from reading about others' diligent work).�
Jan 19, 2015
islandbayy The bleed resistors were bleeding off power from the bricks of cells that had a higher voltage, while simultaneously adding more power to bring up the voltage in the lower bricks of cells. The resistors are small, so it can take a while.�
Jan 19, 2015
dave Here are my updated numbers:
216-220 Rated Miles at 90% Charge:
244-248 Rated Miles at 100% Charge:
Refurb B Battery
VIN 3236: 12/2012 28,000 Miles
I typically charge to 70% 5 days a week, and 90% two days a week.
The range in RM is because I do see the numbers creep up a bit if I do a few deep discharges several days in a row. I never get back more than a few miles though.
I was pissed at my low numbers for a long time, but finally just accepted it and stopped worrying for the most part. Still perturbed at the early advertising when I bought the car, thinking I could actually eek out 300 miles, and 265 was the WORST case scenario.�
Jan 20, 2015
AmpedRealtor I know some are saying that your battery is being balanced, but I don't believe that is the case. What you are describing is the end of the taper curve. Your Amps will gradually drop into the single digits as the battery fills up, and it will take a longer time towards the end. This has nothing to do with battery balancing. Tesla has said that battery balancing occurs in the background and at all charge levels, not just 100%, and it's not something that can be initiated or observed by the user.
For the sake of argument, let's assume that this is the battery pack balancing the individual cells. If true, then it only does this at 100% because that is the only time the slow charging behavior is observed. If that's true, then most Model S cars' batteries will drift way out of balance - potentially to a dangerous point - because many owners don't charge their cars to 100%. What if you NEVER charge to 100%, does that mean your cells will never balance and at some point your pack will become toast? The balancing argument doesn't make much sense if you think about it logically.
The long wait at the end is just the end of the taper curve. The reason some see a recovery of range is because the battery resistance changes more obviously as you get closer to the empty or full endpoints, so the algorithm can make better guesses when it knows the high and low endpoints.�
Jan 20, 2015
mknox What I had reported is that I seemed to have lost quite a few miles at 90% after having charged most of the summer to 70% each day. I would charge to 70% and end the day at about 30%, then repeat. I had heard it was best to operate the battery in the middle of its range. When I needed to go on a trip and charged to 90%, I was concerned about how much it had dropped (from 245 miles at 90% to around 218 miles). I began charging to 90% daily again and saw the miles come back to about 220, but no more.
I have charged to a full 100% a handful of times times since getting the car. It would sit at the "1 minute remaining" mark for maybe 15 or 20 minutes, but this last time it was there for between 1 and 2 hours before I decided to bail. I'm not sure if there is a relationship, but I have not been able to obtain full braking re-gen under any conditions for a few months now too. I get about 45 kW but the scale goes up to 60.�
Jan 20, 2015
efusco Maybe somewhere in the past 197 pages and 1966 posts someone else has had this observation, but I'll risk repeating here....
Over the past week while on vacation I left my Model S with 46,000 miles on the 50% charge level while away. Prior to this trip I'd been consistently seeing 227 miles on the 90% charge level that I use day to day.When I set the charge level back to 90% after my vacation it charged to 238 miles. This was prior to updating to Firmware 6.1.
I'll try to report back tomorrow after a second charge to 90%.�
Jan 20, 2015
Pilot_51 My experience with increased range has always been after a low SoC.
Nearly all my driving had been within about 50 miles a day. My range at 80% had dropped from about 162 miles at delivery down to 147 and appeared to settle there, until last month when I had to pick up and drop off a friend 22 miles away for 88 miles total and I intentionally didn't charge between trips. Finished the day with 37 miles. After charging back to 80%, I had 148 miles. A week or two later, I magically gained another mile.
Last week, for some reason it failed to charge overnight and I got in the car on Friday to find 62 miles (about 12 less than when I got home, mostly due to preheating), for a 46 mile round trip with temps in the teens (F). That was the first time in 7 months, since driving ICE, that I had any real range anxiety, but at least I had a backup plan to charge at a station about a mile from work if I decided I needed it. It was undoubtedly my fault entirely for not making sure it was ready to charge after plugging in, albeit because I was distracted by pulling dashcam footage of an accident that evening. I delayed a few minutes to bring it up to 67 miles and double-check with VT how much I've historically used, figuring I could make it to work and back no problem if I go into hypermile mode. Got to work without using heat (not too bad since it was preheated) with 42 miles and made it back home with 10 miles, using comfortably low heat on the last half.
After that experience, it was a no-brainer to charge to 90% during the winter when a sizable chunk of energy is lost to HVAC and friction brakes, and I don't want any range anxiety when it inevitably doesn't charge overnight again. So, I charged back to 80% since I expected another small jump in range that I wanted to log, which was 150 miles. Then on Sunday night, I set it to 90%, which has since yielded 169 miles.�
Jan 20, 2015
apacheguy Yes, please report back. Interested to see if this holds.�
Jan 21, 2015
efusco Well, my 90% charge was down to 229 miles rated this morning--more consistent with my norm. Appears it was a transient bump due to the week long 50% charge.�
Jan 27, 2015
mknox Downloaded and installed 6.1 yesterday afternoon. This morning, my 90% charge yielded 217 miles. Yesterday on 6.0 I got 218 miles and the day before that 217 miles. Once again, no "new firmware" bump for me!
EDIT: You'll notice a few posts up I mentioned creeping back up to about 220 miles at 90%. I've started charging to 60% or so on weekends again, and leaving my car at 50 or 60% when it's parked for a few days, and have seen my 90% range drop back down to to the 217 I mention above.�
Jan 29, 2015
walla2 My car recently got a 6.0 update that pushed my 90% rated range to 243 @ ~10,500 miles. It has held for many weeks now.
Last time, it held for awhile and dropped back down, but this time it seems to be staying.
Still using my refurb A.�
Jan 29, 2015
tomas same experience w/6.1. Had false bumps with prior updates but this time holding with all charges proportional to 265 max. Have not done full charge tho, and that will tell the tale. Have not had over 255 since mid '13. Not complaining at all just reporting. It is clear there has been a lot of messing w algorithm so hard to ever compare to other eras.�
Jan 29, 2015
apacheguy Weird. Firmware updates are known to reset the BMS which in turn erases the range calculation. I have always seen temporary increases in the hours after the update completes, but certainly not days or weeks later.�
Jan 29, 2015
tomas conjecture: many reports of owners with rated drops who bring in car and tesla does all the metrics and pronounces battery healthy. I think they are trying to figure out and address whatever it is that causes rated to get out of synch. Thus new behavior each release.�
Jan 29, 2015
mknox So why do I never see this? I have an A-pack and about 41,000 miles in case that matters. As posted above I see zero change over these firmware updates. Really curious to know why this is. I have also never seen the snowflake icon/blue bar on my power meter either even though the car may have sat unplugged at near 0 F for 8+ hours. I will have a Re-Gen Disabled message and a Power Limit line, but no snowflake. It's not a problem for me as far as I can tell, but what could possibly be different with my car???�
Jan 29, 2015
tomas Maybe yours is a knock off!?!?�
Jan 29, 2015
rlang59 For what it's worth I have never seen the range increase after a firmware update either.�
Jan 29, 2015
walla2 I have only seen the range increase with a service call update. OTA updates never reset the bms in my experience so maybe a service visit is your solution.�
Jan 29, 2015
Jaff See, I told ya Mike...there is no such thing as an S 73...:wink:
�
Jan 29, 2015
rlcordeiro I must confirm that since 6.1 my wh/mi has dropped from around 350 to less than 310. 90% charge has remained 221. My trip meters have never been reset by any of the upgrades. I too have the A battery and ~41k mi.�
Jan 29, 2015
Fedderman Pre-6.1, I averaged 229-231 miles (rated range) at 90% and 252-254 at 100%.
Immediately after installing 6.1 (2.2.113), my first four charges yielded 242 (90%), 256 (100%), 230 (90%), and 230 (90%) - settling back to my prior averages quickly.
Today I installed a 6.1 update (2.2.115) - and immediateky after the update my rated range jumped by 15 rated miles (from 205 to 220).
I have 19k miles on my A battery.�
Jan 30, 2015
mknox Exact opposite for me and my A-pack. No difference in Rated Miles at all. I reported this many times before... most recently the other day when I got 6.1 (2.2.113). Last night I got 2.2.115 and this morning my 90% charge was exactly the same as it was before at 217 miles. I have about 41,000 miles on the car.�
Jan 30, 2015
tomas Yes you posted it many times before. If you repost it each time someone posts contrary you will be busy. Earmark this for snappiness, I don't mind.�
Jan 30, 2015
AmpedRealtor I've also never seen a range bump since the early 5.x releases. There was a 5.x release, I believe, which did bump up the range a bit for everyone. But since then, nada for me.�
Jan 30, 2015
mknox No worries. I simply post my experiences to further the body of knowledge on these cars and to possibly find out why things seem to work differently for different people. I have seen a few others jump in and say they've experienced no range bump either. There must be some reason for it. The first time I do see a range bump when my firmware is updated, I'll be sure to post that too :smile:�
Jan 30, 2015
Beau24 I have about 36,000 miles on my S and I've seen some pretty significant range reduction. Is this normal? I'm trying to attach a photo from this week.
Tuesday - 222 @ 90%
Wednesday - 218 @ 90%
Thursday - 215 @ 90%
Friday - 215 @ 90%
�
Jan 31, 2015
Maarten ST Tesla Model S battery degradation data - with new data from @pluginamerica http://wp.me/p28gpc-16E�
Jan 31, 2015
mknox That's pretty much what I see myself. A-pack with about 41,000 miles and 23 months of use.�
Jan 31, 2015
SeminoleFSU I have 27k miles and 222 @90% is what I get also.
did you drive it at all those days? If it sits day after day at 90%, I've noticed sometimes it seems to skips a charge if the battery isn't drained far enough.. not sure what the threshold is... Also of note, there is a bug in v6.1 which causes slacker to start playing tunes when the car is supposed to be asleep.. could it be that it did that for a while and drained some juice from your battery? I'd drive it down to less than 100 miles rated or so and then charge back to 90% and see what you get.
�
Jan 31, 2015
johnnyS I am at 36,000 miles on an "A" battery and my 90% charge is 225 miles rated range. I have not done a full range charge since last summer. After charging the number is consistent, but once driving it varies. Sometimes the rated range will drop 10 miles in the first 3 miles of driving. I am not sure how much is due to degradation and how much is the algorithm since it has been a while since doing a range charge.�
Jan 31, 2015
David99 The sudden range change you see is a good indication that the number of rated miles is based on a computer model and is synced on the fly as you drive. Lots of factors play into the usable capacity. Some of these factors change as you drive. I have seen it both ways. I have seen it drop 3 or more miles within a short distance driven and I have seen it stay or only drop very little while driving many more miles. Usable capacity depends a lot on how aggressive you drive and temperature. And it might well be that from the moment when charging is finished to when you actually drive the car, things change. So the rated range display is really a good guess, not an actual measurement.�
Feb 1, 2015
lloyds Now at 50k miles and my 90% is at 227 and full charge at 258.�
Feb 19, 2015
tomas Last few firmware updates, I've had the phenomena where - at first - my rated range at whatever % is proportional to 265 @ 100%. Then, it has slipped down after a few charges and some trips. Usually to full charge ~251.
However, with 6.1, which I've now had about a month, I've had multiple trips, daily charges, a couple of range charges, a couple of "calibration" runs down to <25%. And, it hasn't gone down. Range charge last weekend was 265, and every intermediate charge is still proportional to ~265.
If anything, I'm also seeing slightly better WH/MI than I have previously gotten in same conditions. Is that improved driving habits? Bad memory? Who knows. At any rate, I'm not seeing anything to indicate the increased rated range is at expense of reduced WH/MI bogey.
So, who the heck knows. Clearly they continue to mess with the algorithm. Is it better or worse? I don't have the tools to tell... maybe will request a full diagnostic next time at Service Center. Though I understand they are wont to share any details beyond "your battery is within spec".�
Feb 19, 2015
brianman Matches my experience.�
Feb 20, 2015
mknox Tried another Range Charge yesterday. This time using the 80 amp charger at work. I am on the .140 flavor of v6.1 firmware, which had been updated at the Service Center from .116 the day before. Once again, I cannot seem to get it to "finish". This is after several hours of "1 minute remaining". I even stayed an extra hour at work to see if it would complete, but it didn't so I just unplugged and left. As soon as I pulled out, the range started to drop. Nothing had changed for me once again over a firmware update.
I did ask Service to check and advise on my battery status and they reported back that all is "normal" and the degradation I am seeing is also normal and expected for a two year old car with 42,000 miles.
�
Feb 20, 2015
apacheguy 32 amps is an awfully high current draw at circa 100%. Mine is usually down to <10 amps after 99%.�
Feb 20, 2015
gaswalla You got to do a couple of full charges and give it lots of time to finish.. Your battery is out of balance.
My guess is that you routinely charge to less than 90% and haven't done a range charge for ages�
Feb 20, 2015
mknox There could have been some pack heating running (not cabin heat). Temps were really cold at a bit below 0 F all day, but yes I was getting worried at that much current going in to an apparently "full" battery for so long.
- - - Updated - - -
I actually charge to 90% daily and tried a Range Charge a couple of weeks ago with the same result of it never finishing. Can you define "lots of time to finish"? I thought a couple of hours at the 1 minute remaining mark was "lots" but I guess I could be wrong.�
Feb 20, 2015
Klaus Try it overnight. If it then never finishes you have a case with service.�
Feb 20, 2015
David99 Here is the charge curve from a 100% charge. The bottom blue curve is the power in Ampere. The second curve is the state of charge in percent. The upper curve is the range in miles. Interesting to see that it reaches 100% but still charges at full 40 Amp for a while, then it goes down while the state of charge and range stays the same.
edit: just looked at the some older data from a 100% charge. At that time it had not reached 100% yet but started to reduce the current. It reached 100% shortly after it started to reduce the power and then did the same as seen in this graph, stayed at 100% and decreased power down to zero over about 50 min.
�
Feb 20, 2015
kevincwelch This is what I get on a full charge as well. Mine is 2 years old, but I have 1/4 the miles. If I had your mileage, I'd be OK with it.�
Feb 24, 2015
walla2 As an update, my 2012 Sig with its refurb A on firmware 6.1 is now charging to 242 at 90%. It was 218 only a few months ago on 5.9, and the range is increasing week by week. Haven't seen 242 in a long time.�
Feb 25, 2015
mknox Are you doing anything differently? I seem to be "stuck" at 218 @ 90%. I just got another flavor of 6.1 (.140) and it's still exactly the same.�
Feb 25, 2015
Mario Kadastik Seems that after 6.1 I'm stuck at 379km, was 389km just before. Am at 30800km so ~20k mile mark and slightly worried ig I have really lost 5% of capacity or not... 2.5% that was just before was kind of ok at this distance, but 5% seems odd. And I have done multiple range charges followed by >50% straight consumption immediately after. It's always 379.x km...�
Feb 25, 2015
AmpedRealtor Not fair! My August 2013 car w/ 21,000 miles charges to 228 miles at 90%, with range mode on it goes to 232 at 90%.
I have a B pack.�
Feb 25, 2015
MrPinrel I did a range charge today for the first time in months. when I went to the car in the morning it showed 99% charge (I think they have tweaked how low the car can get while still plugged in before the charging kicks on again), 258 rated miles with range mode off.
December 2013 delivery, D pack, 18k miles.�
Feb 25, 2015
Treker56 Any updates on 60s? Our 2013 24 months with 25K miles charges 90% to 176 miles rated. Haven't done a range charge in a while.�
Feb 25, 2015
dirkhh A week before trading in my S60 with 25k miles in 18 months a 100% charge got me 202 miles, 90% daily charge was 181. That was on .115�
Feb 25, 2015
xhawk101 2013 60 with 30 k miles got 199 max range charge after 2 max charges and balancing. First max gets to 196 miles.�
Feb 25, 2015
mdemetri Well, we are finally about even. My March 2013 car with 22.5K miles gets 229 rated miles at 90% (range mode off). This has improved from ~218 very gradually over the last ~2-3 months with nightly 90% charges. It is still climbing, so I think I will still go higher yet.
How are you charging your car now? Still doing your old 50% routine?�
Feb 25, 2015
walla2 I'm still at 10600 miles so that may be helping my range.. Still convinced my range increase occurred with a manual firmware update and service. OTA updates affect range but not dramatically like what occurred after my last 12 V replacement and manual update.
Also still charging to 90% daily but at a 40 amps now.�
Feb 25, 2015
Klaus MS 60 with 24k miles 100% 201 mi, 90% 181 mi rated - range mode off.�
Feb 25, 2015
DriverOne Almost identical here. Same age and distance. I see 177 miles
�
Feb 25, 2015
UberEV1 My August 2013 S85 with 15,000 miles is charging to 231 miles at 90% with range mode off; very close! I've been charging to 90% when car is being used, and to 65% when I travel, although not sure how much this helps.�
Feb 26, 2015
AmpedRealtor No, I've been charging it to 90% now for months. I've run it down to as low as 8 miles and back up to 90%. I see the same 90% charge every time. The only thing I haven't done in a couple of months is a 100% charge, but only because I haven't needed it.�
Mar 24, 2015
qwk After 2 years, I have amazing capacity still left!
�
Mar 24, 2015
scaesare Ideal miles, right?�
Mar 24, 2015
qwk Yes.�
Mar 29, 2015
glhs272 
�
Mar 30, 2015
glhs272 Updated:
At that same range charge, here is the ideal miles number:
It took a few miles to begin showing less that the 206.
On the way back the next day, I was able to get 52.1 kwh out of the battery.
For reference about a year ago, I was able to get about 54.0 kwh out of the battery on the same trip (different weather conditions and slightly different route). Not sure how representative this is of battery degradation though.
�
Mar 30, 2015
islandbayy I like your range. Just a hair away from 50,000 miles, I should hit 50k when I go in for repairs again... next friday.... My range went up 1 mile after last firmware update. I'm at 202 Rated. ~48,700 miles on car, just under 16,000 miles on new referb battery.�
Mar 30, 2015
glhs272 I am quite happy with how my range is holding up thus far, about 1% range loss at 42K. At this rate, I will still have 196 rated miles at 250K miles.
202 range isn't that bad either at 50K. Maybe we will get lucky and the rate of decay will flatten out even more as we rack up the miles.�
Mar 30, 2015
wycolo 
266 rm after 26k on B battery.
--�
Mar 31, 2015
mkjayakumar glhs272: more than RR, the energy extracted is perhaps a better indicator of your battery capacity. If you were able to extract 54 kWh last year and 52 this year (on a fully charged battery down to zero miles of driving) , that would indicate approx 4% degradation.
You agree?�
Mar 31, 2015
apacheguy @wycolo - that's pretty darn good. What's your daily charge limit?�
Mar 31, 2015
sorka Only 50K miles and you already got a new battery???? What happened?�
Mar 31, 2015
rlang59
See here:
Well, luck finally caught up with me... Main pack failed...�
Mar 31, 2015
glhs272 The extracted energy should be different between the two trips. On the second trip I used a different shorter route (back roads vs. free way) that allowed me to drive slower and use more heat. So not a very good test in that regard, but yes I agree the lower extracted energy should be noted. Also note the different firmware and the fact that on this latest trip the drive limiter was not present, unlike the old trip where I was driving for several miles at limited kw. Thus I believe I ended this latest trip with more range still available in the pack despite showing the same rated miles. I considered making the trip the same as last time, but I found this other route much more pleasing. I guess I need to make another run and just see how much energy I can extract from the pack and see if I can get 54 kwh or greater. Maybe target an identical 312wh/mi consumption rate and see how many miles it will go until I hit the power limiter at that level.�
Mar 31, 2015
tezco That is good. I think the last time I topped off I only got up to 257 rated miles. Of course, I have an A pack and the car is about 2 1/2 years old now.�
Apr 2, 2015
wycolo It was still charging after 266 but I didn't want to waaait out a possible 267. Getting 'one over' the nominal 265rm was good enough for me!!
This was at the 7th SuperCharger in a row as I was preparing to venture off into uncharted territory, so the pack had been exercised somewhat up to that point.
--�
Apr 3, 2015
wycolo I used to keep around 170rm and charge up right before trips but it often was a good bit below that for days at a time. Nowadays in this 'don't worry, be happy' SOC era I'm setting it around 210 or 220. It is still hard to see just where the 90% marker is when I go to reset it.
Maybe this 'do a string of SpCs and then try for a full 265rm' test might be worth doing periodically.
--�
May 16, 2015
glhs272 More about this picture when I return from my trip. Note the kWh extracted from the pack.
�
May 17, 2015
FredTMC This is insane! How are you still getting 207 RR with 45K mi on the ODO?!
brand new my car got 208 mi
now, after 51k mi, I get ~193 mi RR on a full charge. And 173 mi on a "standard" charge.
Note:
- I hardly ever "range charge"
- I hardly ever run the battery down and I charge immediately after
- I don't leave the car sitting around at high SOC or Low SOC�
May 17, 2015
dalamchops
some batteries are just better than others.. I had a 60kwh that was down to 174 90% after 11k, and another one that's still at 187 90% with zero signs of degradation after 7k�
May 17, 2015
Pilot_51 After charging to 80% for about half a year and losing ~15 miles range, then charging to 90%, I got about 165. Since then, it has gradually increased to 173 and still appears to be rising very slowly. I just passed 11k last week. I've never charged over 90% and only went down to 10% once. In this case, it is clearly not a degradation issue, rather an issue of calibration or balancing, at least as far as the regained range proves.�
May 17, 2015
David99 Look at where he lives and where you live.
Average annual temperature in Wisconsin is 45 degree F
Average annual temperature in OC 72 degree F
That makes a big difference. Elon once said (in regards to battery life) it would last 'forever' in Alaska. Temperature is one of the biggest factors in battery aging.�
May 17, 2015
apacheguy This really shouldn't be an issue with liquid cooling/heating. If someone could actually demonstrate a correlation between rated range, battery age, and location, I'd be very interested.�
May 17, 2015
invisik But when the car is not being driven, the average ambient temperature is way lower in WI. So over the life of the pack, the WI pack should last longer....
-m�
May 17, 2015
David99 The battery has a liquid temperature management, but it's not cooled down to the same temperatures as you have on average in Wisconsin. That's not how it works. The battery is actually performing better at warmer temperatures, but unfortunately also aging quicker. The only time it is actively cooled down is when it reaches a dangerous temperature which is when you drive very hard or when you charge at a Supercharger.
The battery is not kept at the same temperature regardless of the outside temperature. This would take a huge amount of energy and make the car inefficient and would have very little advantage.
Again, Elon pointed out that lower ambient temperatures are good for the battery life. The temperature management just keeps it from going too cold and too hot.�
May 17, 2015
SFOTurtle Still, 51k miles and you're at 193 rated, that's pretty good. That's what, maybe 7-8% decrease from new. I have just over 30k and my rated range was 196 the other day, the first time I've charged to 100% in maybe 5 months. If I can still get above 190 rated miles at 50k miles, I'll be pretty happy.�
May 18, 2015
glhs272 So about these pictures... If you read up thread a page or two, I have been comparing my rated range and kWh extracted from the pack between now and a year or so ago. I am doing this to try to get a feel for how much range degradation I am getting. I made this trip again with the intent of not focusing on the rated range number at 100% but what actual kWh I could get. My original trip from a year ago got 54kWh from the battery with a little bit remaining and extracted at 312wh/mi. I did my best to run the same route but because it's warmer now, I had to drive as fast as I could comfortable drive and still hit about 312wh/mi. In summary I was able to get 54.9kWh from the pack. Pretty good I think. Most I have ever gotten in one session. I have run my battery lower before, but not from a full charge where I could get a complete measure of pack capacity. BTW, my charging habits: charge to 90% every day, charge as often as possible. I go on a road trip every 1 to 3 months which usually requires 2 or 3 range charges.
Here are a couple more pics from this trip right towards the end. These data points are just to try to make it easier to compare this one with prior trips.
This one is where the car was at when I hit the 54.0kWh:
This pic is of when I started seeing the power limiting bars.
So how much range degradation? Well it appears not much. Maybe a few miles, I could get 209 to 211 when new.
One minor note: for the last few months a 90% charge usually gets about 183. After this last bit of range charging and run to depletion, my 90% yields a 184-187. So, even though I have been charging to 90% daily, there still may be a tiny bit of out of balance or out of calibration. Thus, I have seen a minor rated range improvement.�
May 18, 2015
FredTMC I guess so.
I think the battery range is only as good as the weakest "string" in the pack
- - - Updated - - -
Yeah... I'm okay with my battery life. That being said, it's strange to see owners with hardly any degradation.�
May 18, 2015
glhs272 There are probably a few different factors effecting my car's battery life. However, one of the reasons I charge only to 90% is because of the "weakest string". My thinking is that I want to wear all of the cells as evenly as possible. If the battery is left to run long for periods out of balance because of charging to lower voltages, it may reduce range faster than the normal degradation due to the slightly higher voltage at 90%SOC. You will have one string of cells work harder than all the rest which will amplify its weakness. This may be BS, but plenty of folks are running this experiment by charging to less than 90% and we can compare. I will be happy to test the always charge to 90% because I need to anyway (60).�
May 19, 2015
mknox Still can't seem to get mine to "stop" charging when it reaches 100%. This was earlier today after about 2 hours at a Supercharger. In this case, 100% = 245 Rated miles.
�
May 19, 2015
Todd Burch mknox, don't you typically charge to 80% (or didn't you used to?) I think your pack is way out of balance. (I noticed that my first car started losing apparent range (manifested by lower 90% or max charges) because I was habitually charging to 80%. On my new car, I charge to 90% most of the time and haven't seen my miles drop off.
Have you charged to 100% and let it run to completion at home lately? Suggest you do this. You're still putting ~5kW into the car....so it's topping off your lower cells.�
May 19, 2015
apacheguy Mine usually sticks at 100% with low current draw for 30 mins or so. It's normal.�
May 20, 2015
mknox This was for two hours at a Supercharger. I've let it run for about 4 hours at work on an 80 amp J1772 station (I have dual chargers) with the same result of never stopping. I either run out of time and have to leave or, honestly, get a little freaked at it throwing that much current for so long into an apparently full battery.
- - - Updated - - -
I did 70% to 30% most of last summer and lost about 25 Rated miles of range when I eventually did a full charge. After that, I started doing 90% regularly and got about 5 miles of range back.
May just bite the bullet and let it run all night at 100% and see what happens :scared:�
May 20, 2015
Todd Burch Pick a cool night to do it, and it actually may not be all that bad...Let it sit at 100% for about 4 hours.�
May 20, 2015
porshuh Very interesting read. Is there a guide for the best way to balance the Tesla pack?
I have a 1st gen Honda Insight right now, and bought a "grid charger" to balance the pack. It charges the cells at about 300ma (they are 8Ah cells), and once the voltage gets up to about 170v (or about 1.4v a cell), you let it run for a few hours, and it "catches up" the lower cells to balance them all.
Could charging the Tesla up to 80% SOC at a fast rate, and then specifically picking a very low amperage to charge it up to 100% help to balance the pack (maybe if done so a couple times in a row with almost full discharges in between)?�
May 20, 2015
brianman Two hours past 100%? I'd definitely shoot an e-mail to Tesla (with the rough timestamp) to see if they can pull the logs to learn anything.�
May 20, 2015
David99
Balancing the Model S is all theory. There is no official info from Tesla about how it happens and when and there is no recommendation on what to do. It definitely happens inside the battery, there is proof for it, but again, Tesla has not made any official recommendations about it. All you read here is speculation.
One common misconception is that not charging to 100% would cause the battery go out of balance. That's not true. The differences in the cells during the manufacturing are responsible for it. Cells are simply not perfectly identical. No matter what you do, they will differ. It makes no difference if you charge half or 3/4 or full, the differences in the cells will always cause them to drift apart. Balancing takes care of it. When exactly it happens is speculation. Most Lithium chargers do it after the charging is complete, but it could technically be done at any state of charge.
One thing that makes the rated miles go down when not charging full cycles is that the capacity can't be measured perfectly accurate. The rated miles are based on the real battery data and a mathematical model. The closer the state of charge is to the extreme ends (empty or full), the more accurate the cell voltage tells you what exact state of charge is. The longer you only run partial cycles the less accurate the data from the battery and the more you have to rely on the calculations and thus the higher the probability the calculation is off. Doing a full cycle on the battery (going from one end to the other) sort of re-calibrates this calculation. Tesla actually explained that in an official email. So charging to 100% after a long period of time of only partially charging it will recalibrate the range prediction. I don't know why so many people insist on saying it's balancing when Tesla specifically said it's a calibration issue and at the same time never mentioned anything about balancing.
One way or another, it is perfectly fine to charge to 100% here and there. It's not going to kill your battery. Doing it every day and leaving the car sitting at 100% for a long time isn't good for the life of the battery.
BTW, your Honda Insight has a different cell type. Nickle based batteries like to be at 100% and balancing them is much easier. You can just carefully 'overcharge' the pack. The lower cells will catch up, while the cells that are full just convert the excess energy into heat without getting damaged. The same thing would be catastrophic for Lithium cells. It would be damaging and they would eventually catch on fire.�
May 20, 2015
Todd Burch I interpreted his comment as meaning two hours total at the supercharger...so probably an hour or so at or near 100%.
- - - Updated - - -
This is true. My personal experience has been:
With my 2012 S85, I frequently charged to 70 or 80% max, and with this saw my max rated range drift downward. Granted, I still believe the overwhelming majority of this was not real battery degredation but either imbalance or algorithmic issues.
With my 2014 P85, I charge to 90% 5 days a week. Doing this, my 90% charge has remained at or above 236 miles for all of the 13,500 miles on the car--and I rarely Supercharge or charge to 100%. If I were to do that once or twice a month, I'm pretty sure it'd be higher.
Anecdotally, it seems to me that some level of balancing happens at 90%. Charging daily to 90% seems to prevent the downward drift in rated range, whereas charging to 80% means your rated range drifts downward. But again, only Tesla knows--and why they don't publically state how this behaves is puzzling to me--especially given that they've now essentially opened up all their patents.
I'd LOVE to hear JB discuss balancing sometime. It would probably put this entire thread to bed.�
May 20, 2015
apacheguy @Todd - I'll let mknox definitively answer this, but I'm most certain he meant to say his car spent 2 hours charging at 100% at the SpC and 4 hours on his HPWC. I agree that something doesn't seem right about that.�
May 20, 2015
David99 I think it has to do with marketing and how they sell the car. They have been very conservative on technical details on how to charge the battery and all that. I think they don't want to portrait the car as something that requires technical knowledge and technical details about how battery imbalance happens and needs to be dealt with and degradation would just put more attention on it. That's what makes people skeptical about EVs. They want to present it as a simple and easy to use technology. Charging and range are the two things where EVs are still falling short compared to ICE cars. It wouldn't be helpful to confuse owners with technical details about battery balancing. It would be one more worry in the back of their head. Car guys like us love all that technical info, but I think for a sales and marketing point of view they want to make it look simple and fool proof. Well that's my theory at least�
May 20, 2015
Todd Burch I agree that's probably why, but that doesn't mean I have to like it�
May 21, 2015
porshuh I wonder if one of us could actually get through to a person in Tesla Engineering to learn what the actual best practices are.
Something like "hey I'm a giant battery nerd, could you please talk about how your packs actually best like to be charged/discharged?"
I've read all the "general" statements about SOC, charge/discharge levels, etc....but I'm sure there's more detail that someone at Tesla could reveal to the true electric car nerds.
Yeah I've read WAY too much information about my 144v pack in my Insight. I was under the assumption that the lithium cells in the MS could be balanced the same way (charging to 90% SOC and then dropping the input Amperage to 1A or something super low and leaving that overnight)...�
May 21, 2015
brianman Whitepapers are good for this kind of thing. You want to geek out, here you go. I don't think people are asking for something on the front page of the website.�
May 21, 2015
mknox Sorry, I was probably not clear. I arrived at the Supercharger with about 30% SOC on the battery and set the slider to 100%. It was plugged in for about 2 1/2 hours, but I didn't check it constantly throughout (was having lunch and walking through a few stores nearby). I have an A-pack and noted that it was charging at about 80 kW when I left the car. I figure it was sitting at 100% for at least an hour, but likely more.�
May 21, 2015
glhs272 A true 100% charge on a supercharger from low ~20% SOC to complete supercharger cut-off usually takes about 2-2.5 hours for my 60. It goes to 80% quickly in about 35mins, it's the last 20% that takes an additional hour and a half.�
May 21, 2015
islandbayy Ive charged my 60 to 100% every day for the last 2 1/2 weeks. My rated range went from 199-202 to 208. Yes, I do cycle my battery low a lot, and no, I don't leave it sit long periods at 100%.�
May 24, 2015
breser The sounds coming from my car while charging on my HPWC in my garage and the water left on the floor under my car disagree with this assumption.�
May 24, 2015
bigsmooth125 The different rated range results you're now getting could also be due to a different and better battery. It would be an interesting experiment if you were to now charge to 80% or less for a while to see if your rated range starts to drift downwards. If it does, it would also be interesting to see if charging to 90% raises the rated range back to where it is now.�
May 25, 2015
AmpedRealtor That's not entirely true. My car actively cools itself while charging at 80A on my HPWC in the garage.�
May 25, 2015
scaesare I wonder if they've changed the algorithm in recent FW versions. I caught my car cooling during HPWC charging a bit back... first time I can ever recall that happening in the 2 years I've owned it.�
May 25, 2015
mknox Oddly, my car is completely silent at Superchargers. At home, on the odd occasion, I'll hear a pump and/or fan but at a seemingly very low setting.�
May 25, 2015
breser My S85 I got in September did the same thing. So if it's recent it's sometime before September.�
May 25, 2015
dirkhh My 60 (VIN 11xxx) would turn on a very loud fan at superchargers - and my P85D does the same. I have caught my 60 turning on the pack cooler in the garage as well in the summer. It hasn't really been all that warm here so far this year and so far I haven't caught my P85D doing that but I see no reason to believe it wouldn't.
I'm actually quite surprised that mknox says his car isn't turning on the fan at superchargers. Both of mine do/did that reliably. Every time I charged for more than a few minutes.�
May 25, 2015
andrewket The type of charger is irrelevant at this point. You're only charging at 12A in your pic. Let the car finish charging to 100% overnight. Your pack clearly needs to balance.�
May 25, 2015
Larry Chanin No doubt they didn't get the email. :wink:
Would you care to share it?
Larry�
May 26, 2015
Mario Kadastik Recently asked Rafael de Mestre about how his battery is doing. He's got over 80k km on it and he claimed that he recently charged to 399km on Typical, which is pretty much what you get on new cars (~401-403km).
Chargelocator Team on Twitter:
So in fact what it's starting to look like is that if you baby the battery your apparent range loss is bigger than when you regularly use it fully (i.e. 100%-0%-100%-0%-...). Wether this holds also for longevity in terms of catastrophic cell failure modes or only for time dependent degradations, but it does look like the battery likes it when it's used more, not less. I think that's also somewhat in line with what islandbayy saw with his 60 which was retaining range quite well even though he went through crazy amounts of milage and did loads of supercharging. Wether his catastrophic failure was correlated or not is a separate question�
May 26, 2015
mknox My first experience with Superchargers was on a trip to Chicago last summer and I paid very close attention as I was expecting the fans/pumps/cooling system to come on... but nothing. It wasn't "hot" but temps in the mid 70's. Now that we have a few Superchargers closer to home, I've noticed the same thing here. In fact I supercharged twice last weekend and the car just sat there quietly. I do have an A-pack battery that can't charge as fast as newer packs. I wonder if this is why?�
May 26, 2015
walla2 I used to think this but many variables are at play. My 2012 car with 11k miles and 6k miles on the replacement pack shows on a range charge yesterday 262 miles. I clearly do not drive very much, routinely charge to 90%, and have reasonable range left despite this.�
May 26, 2015
smartypnz Don't think so.... our A pack will have the fans turn on at SC when hot out. We see temps at the Gilroy SC in the 90- 100 degree range in summer (air temp) and no shade on the asphalt. At home, it will be 55 degrees (yes 45 miles away) and only rarely hear the fans while charging.�
May 26, 2015
mknox I guess I'll have to pay attention when it gets warmer over the summer...�
May 26, 2015
benjiejr P85D with rated range of 250 miles at 100% SOC; 224 miles at 90%. I've lost a few miles over the 5 months I've had it. I'm guessing this is typical but it seems like others are reporting a bit more range. Am I within spec?�
May 26, 2015
dirkhh Tons of factors play into this. Random luck, apparently. How often do you do 100% charges? How often do you draw it down to below 20% (or so)? What are the temperatures where you live? How many miles in those 5 years?
I get 229-230 at 90% on mine, so 224 is about a 2% loss. That seems entirely within the bell curve that has been reported...�
May 26, 2015
benjiejr Thanks for your response @dirkhh. I've only done 100% charge 2 times (and used it quickly afterwards). It's only been below 20% about 4 times (and charged it immediately). Temperatures in San Antonio during this time period have been very moderate and for the most part in the range of 40-85 degrees. I've had the car for 5 months (not years) and have about 8200 miles.�
May 26, 2015
RyanT Here's mine with 10k miles range mode on. I charge to 90% every day and have done a 100% charge at least a dozen times. When I got it, it charged to 270. It might have got to 268 or 269 if I left it go for awhile.�
May 26, 2015
AmpedRealtor Behavior varies with ambient temps. I'm in Arizona where it's in the 90s and low 100s this time of year. Charging at 80A starts out silent, but as charging progresses you hear the car spooling up the different cooling systems.�
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