So my son was getting ready to go skiing and the warning light came on again. I went and checked and it had 12.2V and 580 CCA. I went to Costco and got the regular flooded Interstate H6 for $124 tax included (+$15 core). I hooked up my CTEK charger to terminal in fuse box that goes right to battery and ground point and set it to supply just so I wouldn't lose any info. PSA you will still have voltage at battery cables if you do this. I never got any of the OBD2 plug versions but some I saw need another battery to clamp to. I took out the oldbattery, hardest part was that clip that goes over the hold down post, cleaned all dirt and sand and installed new. New one at test before install was 12.7V and 900CCA.
NOW the issue- new battery is in, I drove to return core, get gas and a couple things for his trip, about 20 minutes and 2 starts. I come out from last stop and low battery warning is on! I check the stuff and I'm at 12.3V and 740CCA. Running is charging at 14.2V, no clue on amps if alternator has a bad diode. I went to Honda and showed them. 2 service advisors said they hadn't seen that message before.
Now to add to strange and recreate to maybe help technician. If you get in, foot on brake and start car, no message, starts right up, cranks normal. If you get in and push key on WITHOUT foot on brake just ignition on, warning message appears. press brake and push start again, starts right up.
I have a loaner CRV, Pilot is waiting to be diagnosed, my son took his Kia Forte to go skiing instead. Honda will do the hood and radio software recalls while it is there. I also noticed a slight seeping wet from tranny at case by middle bolts so that is on the list. 39 months old, 36,519 miles.