Service Visit Confusion, need some feed back

[Ducatipilot]

2013 Model S 75k miles CPO with 18 months left on warranty. Bought her one month or so ago.
Took her to the service center to upgrade to LTE and when i brought her home, the battery doesn't charge to 100%. stops at 96% I was balancing the pack so I ran it down to 1% and timed it so it would be 100% for the morning drive. Anyways now the range has gone from 252 miles at 100% to 240 miles. I called the service center and they said they upgraded my firmware and it has affected how the car calculates the battery percentage and range. At 90% i was getting 247 miles now its 220. That's pretty significant. Oh, and they told me there was an over the air fix coming. sounds like hog wash to me.
any thoughts or similar experiences? Rocklin Service Center in CA.

 

[Tam]

...Anyways now the range has gone from 252 miles at 100% to 240 miles...

Model S and X do not have a degradation warranty.

 

[commasign]

Try another full charge/discharge (or two). It might go back up a bit. 240 miles is a bit low (but not unheard of) for 75,000 miles. Also check your settings to make sure range mode is on. If it’s off, turning it on will give you a few more miles of rated range.

 

[Ande]

"I was balancing the pack so I ran it down to 1%"
Correction:
You may have been helping the BMS to calibrate actual capacity,but not "balancing" anything. Balancing is done continuously regardless of SOC.
The bigger the cell difference is, the longer it takes to get to 100% , as actual charging power is limited to the power the balancing circuit can load on the full cell(s).
By running it down all the way, you caused bigger differences between cell groups as the ones of lesser capacity strated to fall steeply.

 

[TexasEV]

Agree. Let the battery management system manage the battery.

 

[N..8]

2013 Model S 75k miles CPO with 18 months left on warranty. Bought her one month or so ago.
Took her to the service center to upgrade to LTE and when i brought her home, the battery doesn't charge to 100%. stops at 96% I was balancing the pack so I ran it down to 1% and timed it so it would be 100% for the morning drive. Anyways now the range has gone from 252 miles at 100% to 240 miles. I called the service center and they said they upgraded my firmware and it has affected how the car calculates the battery percentage and range. At 90% i was getting 247 miles now its 220. That's pretty significant. Oh, and they told me there was an over the air fix coming. sounds like hog wash to me.
any thoughts or similar experiences? Rocklin Service Center in CA.

Ducati, On a 75 the 90% will be around 220 miles. That's what most of us get on a good day.

 

[MorrisonHiker]

Ducati, On a 75 the 90% will be around 220 miles. That's what most of us get on a good day.

Since it's a 2013, I'm guessing he has an S 85, not a 75.

 

[Ducatipilot]

thanks for the responses. I dont know the lingo abut the batteries very well so balance was obviously not the correct word. however the service person told me to run it down to as low as i could and charge it to 100 because that was part of good battery maintenance. i called the service center today again and they said it was a glitch in the firmware. I dont understand that.

 

[xyeahtony]

Agree. Let the battery management system manage the battery.

I remember a Tesla engineer posting something either here or online saying the BMS automatically balances the pack so these 0-100% charge/discharges everyone keeps recommending isn't necessary and quite redundant. The available power in the battery will always be there, but it may or may not be shown accurately on the battery gauge.

 

[Tam]

Battery balancing and similar procedures have been dispelled by Tesla officials multiple times despite of their own workers' practice and advice.

Those procedures make human driver feeling good for recovering additional miles but they are actually hurting the battery:

"Avoiding deep discharges is another best practice for optimum capacity retention. The advice by the Service Center to "let the range drop down to about 20 miles and then charge it to max Daily Range" is misleading. They are correct that it will mitigate the inaccuracy of the capacity algorithm, resulting in a higher displayed range, but it is misleading as the actual amount of stored energy does not change." Jerome Guillen (former VP, W W Sales & Service).

"However, the only accurate way to measure the amount of energy a battery can store is to fully charge the battery, then completely discharge the battery to zero, then measure the amount of energy that was released. While this would give an accurate measurement, it would not be good for the battery."

If you are worried about your battery status, you might want to have a reading of your battery to see which one fails to hold a charge:






The above picture shows the individual voltage of each 96 bricks (16 modules x 6 = 96 bricks =7,104 cells.)

It's shown in minimum, average, and maximum as well as the difference which in this case 7 millivolts.