islandbayy
Active Member
Thats Awesome!So I would like to finally post an update on my pack swap for my old 2013 MS 60. So on March 20th, I dragged my S60 with replacement battery pack out to Mr. Erickson's place in Armstrong IA. The drive was successful and managed to get both battery and car there in one go.
The pack swap itself was very quick. Paul was able to do the physical swap in a few hours and did some firmware updates overnight. Paul Erickson was a pleasure to work with, an interesting guy and someone dedicated to Tesla Model S cars and helping owners keep them on the road.
The old pack came out OK, and was definitely getting a bit corroded. The usual suspects, the fuse cover plate was very rusted. Didn't look like it was getting water in the pack yet, but it wouldn't be long based on looking at it.
There were complications however. Once we got the pack swapped out and brought the car back on line it immediately threw some errors. One of the big concerns I had with this pack was that it was sitting in storage untouched for over 6 years. It was dry storage, but it wasn't charged or turned on or anything for that period of time. The other concern was I wasn't sure what state of charge it was left at when it was put into storage. It could have been near empty which would have been bad. Turns out I was lucky. It was at 65% state of charge when we turned it back on. However, during those 6 years of sitting idle, the battery did fall out of balance slightly. Almost all cell groups were perfectly balanced except group 42. That group was about 170mV lower than all the rest. I guess not bad since that 170mV of drift took 6 years to accumulate, but that did cause the car to immediately throw an error, and go into charge restriction. But I felt fairly confident that it was just due to sitting for 6 years and that the pack is overall healthy.
So, I left the car with him for a while to see what he could do. What we did was just simply cycle the pack as much as we could for a little while. Pretty quickly the imbalance was only about 120mV when the pack was down to ~25% state of charge. Did a few charge cycles and reset the error message. After that, it appeared that the error message did not come back. Due to work and other issues, I was not able to go pick up the car for about a month. I left it with Paul and he exercised the pack, did some test drives, supercharged the car a few times and no more error messages came back.
So this weekend I flew myself and my Dad over to Paul's place to pick up the car as it seems to be working normally. My dad drove it home and had no issues with the car driving back the whole way. It behaves just like an 85 pack should (nerfed supercharging) but seems to be good. Currently the cell imbalance is about 90mV @ 80% SOC and 120mV @100% SOC. A full charge yields about 230miles of rated range on the display. Paul is recommending that I try just slow charging to 100% everyday for a while to see if the pack starts balancing on it's own, so I will do that and give an update if that yields results.
Unfortunately, not all is well with the car. Unrelated to this battery business, just prior to me sending the car to Paul, the drive unit (I think) seems like it is giving off some vibration. But maybe more on that in another thread. As far as the battery swap goes, I consider it a success.
Keep charging to 100%, it will keep balancing out. Lower SOC discharges to 100% help too. Since you have free supercharging, spend a couple hours at one getting to 100% (from any SOC). They balance better at a supercharger.
