Drove 75 miles Saturday, parked and battery was 2 bars away from green. Did not drive my car yesterday, was 95 outside. Got it in today and the battery was so drained it moved like a snail until it charged up. Drove just fine after that. Did a health check and all that with Dr. Prius. No issues.
This is a known problem of old Prius, especially when pack gets old and looses capacity and needs deep cycling to restore capacity. Also corrosion builds up from the hybrid battery in the battery ECU and you may be able to eliminate this symptom by cleaning the pins where they solder to the board inside the battery ECU.
Oddly, I did notice the day before it went flat, my MFD was showing a lot more "cars" meaning a lot more regeneration going on, and it was the normal route.
Usually when people notice more reg (cars) than normal on the screen and post about it on here it eventually turns out to not being related to problems, just creates confusion more than anything.
Ya I'm kinda at a loss. It's only done it once before this year when it sat parked a couple days in like 95-98 degree heat. It worked fine again today.
