Another runout test

I took an out-n-back drive to try and burn off the rest of the 100% charge the dealer sent me off
with in the 2021, and may have mis-estimated headwinds on the way back. So there was a minor
scare on that return leg; somewhere around 15 miles left on the GOM, it suddenly went to "---"
miles left but still with 4% or so indicated SOC. I hadn't seen the "---" until well into 1% with the
2019, so I didn't know if the BMS had detected something marginal and was about to strand me
on an interstate or what. Still about 12 ? miles from home I diverted enough to reach a known
level-2 charging spot -- all of half an hour on it would be plenty.

The location was the same place where I'd first tested the Lectron Tesla-destination adapter, with
two Tesla heads and two J1772 Clippers. I pulled into the J1772 bay to be nice, and plugged in.
There were already two Teslas sitting there, one of them on the other J-plug with an adapter for
some reason, and I pulled in between them. Well, the J-plug I started with didn't begin charging --
it had power and all, but wouldn't kick the Kona into accepting it. So I gave up on that, hauled one
of the Tesla heads over, and hooked up the Lectron. That seemed fine, giving the typical 6.2 kW
from commercial 3-phase.

The cell voltages were still all within .02 of each other, even at that low SOC. After maybe 20
minutes the GOM suddenly jumped back to 16 miles. Huh? It seemed confused, but it was clear
that I had enough to get home via the gentler of two paths. It went back to "---" during that, but
I knew not to worry.

I got home without incident, and started the "stationary rundown" routine -- front and rear defrost on
with heat and A/C enabled, fan at max, both seat-heaters full, etc. Blowing off whatever energy
remained as heat, down through 0% SOC real and indicated, until the pack relays dropped and the
LDC shut down. A solid "---" miles through all of that, of course.

Then, recharging. I expected that the drain beyond the lower limit of the GOM might help it reset, so I
hung out with it for a while. Nothing for a long time. Hmm, was it going to try and do a full recalibration?
Then, around 5 or 6%, the GOM suddenly jumped to 15 miles and continued to advance. So the newer
firmware doesn't try to guesstimate miles at really low charge, perhaps? Might have to play with this
again later on.

Also, at the extreme bottom of charge there was a bit more high-to-low cell variation -- as much as
0.1, but nothing seemed to brick itself on that account. In general, the high/low cell *numbers*
reassuringly jump around quite a bit more than they did in the 2019, so maybe they've improved
the scanning algorithm or introduced some randomness WRT reporting to OBD2.

It's still charging and right back to less than 0.02 hi/lo difference, and will go to 100% to run the full range
in a single time block. I really do wonder if any top-balancing is done with these, i.e. do the BCM boxes
have any cell bleeders, or maybe even some active transfer?

_H*

 

This morning, the GOM showed 345 miles. 100% indicated SOC, 97% OBD2 reported.

I went out for a quick highway loop to bring that down a little, returning with no-load
cell voltages just under 4, at 82% indicated.

_H*

 

I think the lowest was just under 3V at "dead", and as we've seen in other reports, full weighs
in around 4.14 V with less deviation.

I probably would have burned off a bit more on the highway loop but there were numerous slowdowns
from traffic volume and several crash scenes. Nice day, people out, not paying attention, etc..

_H*