IanL wrote:When I got my 30kWh model at 2 years old and 31,000 miles, I didn't know about Spy, but I calculated SOH based on dashboard data and charging records. If my method is valid, the SOH was 94% and the winter range (winters are mild here) was 112. I did eight charges (using the 10A plug-in charger) to 100%, because I didn't know any better. Then I started a 30% to 80% regime. By the next winter, the SOH was 102% and the range improved to 120 miles. At that point, the cell-pair voltages were pretty even, with about eight at 0.02V below the others.
I carried on with 100% charges every 4 recharges or so, till I saw that all cells read the same, and I then stopped the balancing charges and haven't done any for 8 months. The cells have remained balanced. At 39,000 miles, the SOH averages about 102.5% and the winter range about 120 miles. During that time, I fitted a wall box charger which can do 32A, but I usually use 16A, because what's the hurry?
My home-grown SOH method may not be valid (Spy just reports 100% by readout from the BMS, not max & min det), but there's some evidence that a measure of recovery is possible.
Good call. Charging that car at 32 amp would exceed the ideal charging speed. IIRC correctly, that battery pack is 2 modules of 40 Ah useable, so the full pack is 80 Ah. With the ideal charging amperage being 25% of the Ah rating, that means 20 amp is the maximum ideal charging speed for the 30 kWh pack. For the 27 kWh pack, the ideal maximum charging rate is 18.75 Ah. So yeah, if you're not in a hurry, don't exceed those numbers!
I try to store at a medium-ish state of charge, and then wait until the last convenient moment to charge it any higher. I do that with everything I own with a lithium ion battery (cell phone, e-reader, e-bike, e-car, you name it). I definitely do not plug my phone in and leave it on the charger all night anymore! In fact, my phone is never plugged in at night. And I don't fast charge it when there isn't a need, either.
Though this does mean, having never drained the Soul EV below 18%, nor ever charged it to 100% in all the time we've owned it, we have NO idea what the SOH is. But Soul Spy reports that the cells are still nicely in balance, so there's likely no need. If they ever get enough out of balance to require a conditioning charge, then we'll make sure to drop below 18% first so that we also get an SOH reading.