I’ve been asked how are batteries are holding up. They are about 7 years old now and were abused a bit throughout their life, more-so early on when we were following the advice of others about BMS and states of charge and charge cycles. We’ve learned a lot since then and if you’ve read my previous posts you are familiar with much of it.
So what’s new? As of last year we removed 5 of our 99 cells and replaced them. Those 5 cells had less than 75% capacity left in them…or so it seemed. This year we haven’t done a thing. The pack was down to about 90% capacity last year. This year the slow dwindling continues and it’s down about another 2-3% depending on weather conditions (about 87%)., which reduces our usable range on a highway trip to about 180 miles. I don’t think that’s too bad at all; at this rate we’ll still have a 150 mile range when the car is 16 years old (old enough to drive itself). Who knows. By then we’ll probably be looking for the new, lighter, more energy dense cells that don’t exist commercially yet…so you know, Teslas’ old cells.