Spontaneous loss of EV (indicated) range

That could be a failing 12 volt accessory battery. A lot of gremlins, especially those at startup, can be caused by low voltage in that circuit.

 

I would agree with Michael33, this looks like an empty (or faulty) 12 V battery instance. It never happened to me, but a neighbor of mine has a Prius (2008, I believe) and once he called me in despair because he could not start it anymore. I went to his rescue and sure enough the display was acting up. He told me he had been waiting for somebody in his car, listening to the radio, lights on and main power off for quite some time. To cut a long story short, I jump-started it and told him, in the future, to make sure main power (i.e. power train and all the works) was on. The 12 V battery is tiny and will run empty in no time if the system is left in "accessory power" (that is pushing "Power" once or twice without holding the brake pedal down, or pushing "Power" with your foot on the brake and then switching the transaxle from P to N). This holds true for both the "normal" Prius and the PIP.

 

That's strange. You are not sure if you got a full charge but still got 12 EV miles total (but est was 6.6). Another full charge still shows 6.8 so it is increasing.

Why did the est dropped to 6.6 in the first place? Did you leave the car on by any chance? The only way I can think of is something drained it and the car was estimating based of the consumption.

 

i would disconnect the 12v negative for a minute. if everything is okay, range should go back to 13.3 or so. definitely test the 12v for health.

 

Keep us posted if anything changes. This is weird.

 

Did you try bisco's advice?

 

Before you disconnect the accessory battery and lose all stored settings, try taking a voltage reading at the accessory battery terminals or jumpstart terminals if present, a few hours after turning the car off after a drive. It should be up around 13 volts at rest. If it's closer to 12 volts, you have a dying or starved battery. Keep in mind that these problems with a dying 12V battery can be intermittent at first, getting worse as time passes.

 

Here are the voltages to expect based on battery charge. This is information from the Prius manual.
12-volt battery Open voltage at 68 °F (20 °C):
12.6 - 12.8 V Fully charged
12.2 - 12.4 V Half charged
11. 5 - 11.9 V Discharged
(Voltage is checked 20 minutes after the hysystem and all lights are turned off.)

 

My manual says (in the specs section):
Fully charged: 12.5 V or over.
Half charged: 11.0 - 12.5 V
Discharged: Under 11.0 V
I wonder if they made changes (improvements?) in the 2013 battery?

 

mike, if those symptoms are due to a bad 12v, i think you'd be lucky. it sounds more like a bigger issue than that though. i think i'd run it by the dealer if the 12v is good.

 

Yes, the specs I quoted are on page 618 of the 2012 manual and the specs you quote are on page 618 of the 2013 PHV manual. I must say the Half Charged range is quite large in the 2013 manual. I believe the low value is incorrect. It can't be "half charged" and "discharged" at 11 volts. I suspect the 11.0 in the Half charged spec should actually be 12.0.

Also, another strange thing. The 2013 PHV manual says "Voltage is checked 30 seconds after the hybrid system and all lights are turned off." In my experience it takes more than 30 seconds after things are turned off for the battery voltage to "settle down", at least a couple of minutes. 30 minutes (similar to 20 minutes for the 2012) would make a lot more sense.

 

You obviously need a new battery. Bet that will solve your problem entirely and bring the car back to starting with 1 button press.

 

all the best!

 

12 volt batt should be covered 100% by std warranty correct?

 

or is it prorata?