Range after 15K Miles

[wiztecy]

Thanks Doug for the follow up.

[strider]

Yes, standard mode charging will slowly balance the pack - it can take a couple of weeks. Range mode apparently does more balancing than standard mode. Never beeen explained why or how, but from observation it does appear to be true.

Now I'm not an engineer but I play one on TV... My assertion is that it's easier for the BMS to tell if a cell is at 100% vs 90% and so it can get the cells closer to balance in range mode than in standard mode. Check out this thread: Roadster Owner Based Study of Battery Pack Capacity Over Time and in there are instructions about using the log parser and it will also talk about how to view the "weakest" sheet (group of cells). The sheet number should change over time. If it doesn't then that means you have a bad sheet and should take it in to Tesla.

[bolosky]

Your pack probably isn't balanced. Do a Range mode charge, let it sit a couple of hours, then take it out for a spin to drop it back down from 100% charge. See if that improves your standard charge range.

Tesla replaced the battery in my car (under warranty) at the 24K service with a battery with 6K miles on it. The "new" battery had been sitting around unused for a long time and was horribly out of balance. When I first charged it it was getting in the high 160s (after finishing a standard mode charge and letting it sit for a few hours). At the suggestion of our service manager I range mode charged it and let it sit at full range mode for a long time (I think it took about four days in total). After it finished balancing it would charge up to the high 180s, so I added ~20 miles of range by the long balancing procedure.

Now, with 41K miles on the car (and so ~32K miles on the battery) it's charges up to somewhere in the 182-187 range (again after letting it sit for a while after the charge completes). I think that the replacement battery I got was a good one.

[wiztecy]

Thanks bolosky, that's a great data point and information on balancing the battery pack!

What was the the reason for the battery pack

[bolosky]

What was the the reason for the battery pack

The service manager said that there were some bad rivets in the battery, so they replaced it under warranty. I had never noticed a problem with it.

[Gary1M]

My 1.5 Roadster just reached 15,000 miles yesterday. After last night's standard mode charge the ideal range showed 187 this morning. Over the past year and 9,500 miles that I've owned this car, the highest ideal range I recall seeing is 189 so there has been very little reduction in range during this time.

[Doug_G]

My 1.5 Roadster just reached 15,000 miles yesterday. After last night's standard mode charge the ideal range showed 187 this morning. Over the past year and 9,500 miles that I've owned this car, the highest ideal range I recall seeing is 189 so there has been very little reduction in range during this time.

Interesting. My car has about the same mileage, and my standard mode charge is coming in at 293 km / 183 miles. When the car was new it was about 300 km / 188 miles.

[Gary1M]

Interesting. My car has about the same mileage, and my standard mode charge is coming in at 293 km / 183 miles. When the car was new it was about 300 km / 188 miles.

I guess I've been lucky up to this point though I've been very careful with charging it in standard mode each night. I've only charged it once in range mode and never in performance mode.

Each morning I check the ideal range and it's typically 186 or 187 miles. Tuesday morning it showed a new low of 185 so I figured it was the beginning of the expected range reduction due to the age of the car and mileage. I was pleased to see it back to 187 this morning!

[Doug_G]

I guess I've been lucky up to this point though I've been very careful with charging it in standard mode each night. I've only charged it once in range mode and never in performance mode.

Each morning I check the ideal range and it's typically 186 or 187 miles. Tuesday morning it showed a new low of 185 so I figured it was the beginning of the expected range reduction due to the age of the car and mileage. I was pleased to see it back to 187 this morning!

You can't take one day as a data point - it can vary a bit due to recent usage, it seems. Also it matters how long you wait before checking - the mileage drops slowly after the charging has finished.

[Gary1M]

You can't take one day as a data point - it can vary a bit due to recent usage, it seems. Also it matters how long you wait before checking - the mileage drops slowly after the charging has finished.

Agreed, I have noticed on the days I don't take the Roadster that I've lost about a mile or two of ideal range during the course of the day.

The factors around my daily observations are fairly consistant day to day. The car begins charging at 1:00am, I head out for the day about the same time each morning after checking the recharge went OK and note the ideal range estimate, then return home that evening with about 110 miles of range left so the amount of daily recharge has little variation.

In any case, the 185 - 187 mile ideal range more than meets my needs (plus I have hcsharp's cool J-1772 adapter in case I happen to need a recharge along the way!).