During UK lockdown I am using the Energy Monitor graphic to keep a check on the charge state of the main batteries on my 2007 Prius. If I park the vehicle with 6-7 blue bars showing, after a few days, it can be down to 2 bars. After 6 miles of driving it is back up to 6-7. Should I be concerned about this? The car starts and drives perfectly but I am worried that if the charge falls to zero bars it might not power-up. It is not a practical long-term proposition to have to drive the car every two or three days just to prevent the main batteries exhausting. Also, does anyone know the significance of the different colours used to show the battery state bars on the Energy Monitor screen. They can be dark blue, light blue, purple or green (at least) and I have no idea why.
The color of these bars correspondences with their number and the SoC. Here's a table: SOC – Prius Wiki SM-G950F ?
Many thanks for this. Even one bar seems to represent at least 40% charge, which is encouraging. I seem to get three shades of blue (light, medium and purple), which doesn't tie up with the table
Looks like the traction battery is getting old. Reconditioning might help, but that's more for balancing the cells than for rejuvenating the chemistry. You're right about the fact that the car keeps a reserve, but it sounds like that reserve would drain away pretty quickly. I'd suggest pairing up the Dr. Prius app on your phone with a bluetooth OBDII adapter and running a diagnostic to give you an idea of the battery's health.
Yes, those are early indications that you have one or more modules becoming significantly weaker than the others. Typically due to self discharge of one of the 6 internal cells in the module.