Note that what you’re describing likely has far more to do with the BMS software and how it displays range at full then with ACTUAL range or battery degradation. Do a range test under controlled circumstances, then a year from now do the same exact range test controlling for as many variables as possible. Then you will know if you have any actual battery degradation. Or you could just enjoy driving the car.
Right. Up to 18k miles, my "range at 100%" had dropped 1-2%, mostly in the first months. That with the initial "range" at 310 miles. This is for my P3D-, stealth performance. Rated the same miles as the non-stealth DM-AWD. But wait, the new Performance 3 is rated at 299 miles versus 322 miles for the same AWD. Even the stealth 3 is obviously not as efficient as the AWD. Probably a little better than the full performance though. I have an average Wh/mi at 19k of 329. Not efficient but mostly because I just don't give a sh*t. I just drive. Probably 90% of those miles are on the interstate cruising at 85 mph. Speed limit here 80. I commute 150 miles one way and then 150 miles back once a week. Easy drive but hills and wind.
Then I had another predicted drop several weeks ago of 1-3%, and oh, guess what, there had been a software update just before that drop. There's your uncle's monkey right there. But there's always a software update. Coincidence is an unruly player. Nevertheless, I did not appreciate a computer telling me that I could drive 5-10 miles less at 100% charge. Excuse me! I beg your pardon, I don't appreciate that one little bit. Jerk! So I switched to % charge and mind your own business. I'll ostrich that sand in one fell swoop.
What I have done and will continue to do is monitor my efficiency and range over time, as suggested by the always sensible and knowledgable EnrgyNDpndnce. Even with the predicted drop my range for the last 1k miles has been the same and at times better. But as with an ICE vehicle, I'm not likely to notice a difference of 10-15 miles on a full tank/battery. Conditions can account for more than that. I can of course drive more efficiently and get better than the predicted range. I have done that on my commute and gotten better than the 310 miles. I have also played with the BMS balance question and have "gotten back some miles" but the truth is it jumps around regardless of my charging habits. Coincidence rarely hides in a corner.
The point is those numbers ain't real. Even unreal numbers, however, that drop are unsettling. But is the drop even real? And why does this bother us? It bothers us because we have more experience with ICE than with EVs. Our experience with batteries is that they Duracell out. We have to replace them. That's what we know, our experience with every battery we have ever owned. Same with an internal combustion engine but that one we know, and accept. I have gotten 200k-300k+ miles from internal combustion engines, mostly diesel. I'm cool with that. But now for the unknown...........new electric vehicle battery life.........hold tight .......we have after all committed to this experiment so let's play it out. And when I say play it out I would emphasize the play part........At worse with loss of range as the battery ages we would have to charge slightly more often. At what point do you replace a battery because you have to charge it slightly more often? Depends, right? Circumstance, necessity, and convenience.
