Never had this happen until this morning. Since I uploaded this video, it was still charging both batteries and was up to the fourth led. Weird!
Yes, that's my theory too. Just checked a minute ago... they both went to completion.Yep, usually happens briefly before one is recognised as slightly higher charge, then the weaker one drops out to be next in line.
The were both onto the 3rd led, so maybe they were identical % and it overrode normal procedure ?
My Spark oem charger does 3 simultaneously, very handy.