my 2008 prius suddenly quit on me while driving the dash went out when it did, however the lights and locks work, when I push the start button I get nothing.
I no longer have my Prius. 6 months ago I traded it in for a 2014 Ford C-Max and I had the same problem with the C-Max that you have with the Prius. The C-Max only had 3K miles on it. The dealer replaced the 12V battery and three weeks later the same thing happened. I brought it back to the dealer and they said they had to reprogram a computer module. That seemed to fix it (so far).
OP stated both batteries good.......there shouldn't be a reason all the dash lights go out. If it's a bad combination meter, the car wouldn't stop running. If it overheated or ran out of gas, he still will have his dash lights. I did read about someone blowing a fuse and the car died..........
Last Saturday evening we were heading for a local restaurant in the "trusty" 2010 Prius IV and ... the car would not start and presented me with a message that there was a P Brake Malfunction. I was instructed to move the car to a level position and put the parking brake on - a nonsensical instruction since we live in SW Florida where it's hard to get beyond absolutely flat! The next morning the Prius was completely dead - not a sign of any life when I tried to start the car. I looked through the forums to find this was, most likely, a battery issue. The car still had the original battery which was now 4 1/2 years old. Following the suggestion of many I ordered a "Yellow Top" battery (made by Optima) from elearnaid. Since I placed the order on Sunday the battery was not shipped from CA until Monday afternoon. By late Wednesday morning the new battery was delivered in FL! The installation was easy and the instruction sheets quite clear. I've now got my "normal" 2010 Prius back with a strong AGM 12v battery in place. From my experience with AGM batteries, this should last for quite a few years. UPDATE (Oct. 7, 2015): The verdict on the Optima battery is in - it failed in one year's time! After being out of town for some weeks, I returned to a dead battery. After the AAA came over and got the Prius started, I took the car for a 45 minute drive and checked that the car would start after returning. Then, the next morning ... dead battery again. I tried jumping the battery, but had no success. At that point I made the decision to dump the failed Optima battery (purchased online) and purchase a battery locally (Batteries Plus). I now have a Duracell Ultra Platinum AGM in the car with a warranty which I can easily exercise should this battery fail.
I would absolutely agree with everything you said except................ There have also been quite a few owners post on here that their new Optima battery failed in the first 6 months or so. It seems like their quality has gone down recently. Please keep us posted if your situation changes.
From what I've read about the Optima batteries, if you get a new one that measures above 12.5 volts, it should not give you any problems. Many have received batteries that are below or well below the 12.5 volts and those are the ones that are having issues. My replacement optima battery came fully charged at 12.9 volts and it hasn't given me any issues for almost a year....and I've deep cycled this battery multiple times. The original optima I had came with 12.3 volts and that one had to be returned after 1/2 year from not holding a charge above 11.9 volts overnight.
Good information. And regardless of whether the "instructions" says to or not, it is ALWAYS a good idea to check the output voltage AND connect it overnight to a tender-type charger at or near to it's first use. That kind of falls into the same category as checking the oil level immediately after every change and the tire pressures after every rotation.
hmm, my car died and the first thing I'm gonna do is post in a forum asking people who have no access to my car what's wrong with my car instead of taking it to a car shop and have it physically checked out and never come back to the forum.