A couple of days ago I decided to level-2 charge to 100% and watch the latter stages of it
closely in terms of cell deviation. Normally the DC current going into the pack runs around
18 - 20 amps, which is a 0.1C rate for the tripled-up cellblocks. As it approached the top, the
OBC dropped current down by degrees and it was only 5A just before terminating. Once
finished, the "real SOC" was still well under the displayed 100% ...
but even at the top of charge, the high/low cell figures were never more than 0.02V apart.
This is just afterward, with my phone running my usual OBD2 "dashboard". I have *not* had
any BMS firmware updates so far, for a handful of reasons including that I don't trust any
of the local dealers to not screw it up. I can watch for hazardous conditions and limit
extremes on my own for now.
I misspoke about full-charge voltage in some other post, where I said it stayed under 4.1V.
Clearly it goes a little above that but frankly, I wouldn't start worrying until something rose
over 4.2. If I stay at displayed 80 or 90% for normal charges the cells will rarely crest 4V,
unless something goes really wrong.
I saw nothing that I could identify as active balancing during the top taper, pack temps
remained about the same as ambient, and the charger and VCU/motor assembly were the
usual warm as the charging system runs the coolant loop through all of that when working, due
to the 10%-ish inefficiency producing about 700 watts that need to go somewhere. There
was no warmth at all in the hoses connected at the front of the pack.
I found that enough electronics power up during charging that even with the car "off", I could
talk to my bluetooth OBD2 dongle -- from cozily inside the house, yet, and watch the min/max
figures slowly progress upward. The cell *numbers* for each also did about what they always
do, settle on 1 and 84 with occasional blips to something else on one scan cycle. Per the other
Torque thread, I'd love to learn how those figures come up for other OBD2-jockey owners.
_H*
