I've experienced similar to you. You can click my name and look at some of the threads I started for more info.
My battery is definitely impacted by cold weather. It's finally getting warm out and the bike ran like a champ today. I expect it to continue to do well until it gets cold again. My bike has 40k miles on it, including about 10k since the SOC wonkiness has showed up significantly last fall. Assuming you're in the northern hemisphere, did you store you bike over winter and just start riding or was it doing fine in colder times?
I hadn't looked at the charging until you mentioned it. I checked my logs and my charger cycles between 9 and 13 amps. I don't have a DeltaQ charger to compare. I'm curious, does using it resolve your issues the the SOC?
Fellow Zero riders, my DS has strange behavior of which I am curious about your opinion.
Since a few weeks I notice that the SoC is acting weird. Although the consumption on dislay (wh/km) is normal (avg ~50wh/km when driving smoothly on inner roads) the SoC runs down harder than before. For example, today I drove 107km and on my return only 18% SoC left. But when I key it back on after half an hour, the SoC is back to 31%. When I then connect the OBC, the SoC jumps to 45% within another 20/30 minutes. I'm used to an occasional percent or what increase, but not 27% in an hour of which only 20/30 minutes charging. 2 weeks back the exact same thing happened (with different weather conditions btw)
In addition, the charging process (in the app) also shows crazy things. Via the onboard charger (OBC) it charges with between 8A and 13A. That fluctuation doesn't seem normal to me. If I connect the QuiQ charger, it does charge constantly.
My conclusion is that the BMS is a bit confused by the fluctuating (and probably dying OBC, as is the case with many Zeros) and the battery is no longer 100% topped off. Cell balance at 100% SoC is 2mV, so that seems to be decent.
So from now on I'll just charge with the QuiQ chargers, but am curious about the opinions here....