On a lovely fall day in 2011, I finished my workout at the Downtown Y and was ready to head home. But when I pressed the Start button on my Prius, all the lights on the dash came on; some were flashing. Upon checking the owner's manual, it advised to call Toyota service. I explained the situation and they asked if it was drivable; if so, bring it in and they'll look at it. I hung up and headed over.
I didn't even make it a mile down the road when the car quit. I called again and they offered a tow truck. I called my boyfriend and asked him to pick me up after work. He talked to his co-workers about my situation and oddly, one of them identified the problem with my car! The source of this was very unexpected: she was not a Prius owner but the wife of a GM Dealership General Manager and knew it because of discussions with him. She knew more about my car than the customer service person answering the phone for the service department at Toyota! To be fair, I don't expect them to be able to troubleshoot over the phone but I do expect them to know when to hand it off to someone with more knowledge on the subject.
So, the fun thing about a Toyota Prius 12v battery is that it keeps on going like the Energizer Bunny all the way up until it doesn't. There are no warnings, no service lights, no message on the 7" touch screen! Nada!
7 years later, around midnight last night, I was stranded at the QuickTrip with a dead battery--I made the mistake of shutting off the car to get gas. Thanks to the assistance of a fellow customer, I was able to jump my car and make it home.
After that first incident of being stranded, I have learned from various Prius owner's forums that there's a multi-step process that can be used to enter service mode and check the 12v battery level. I checked it after I got home and it was definitely low--10v was all it was providing. But this should be easier. After all, the 7" display defaults to showing the charge level of the battery but only the hybrid's battery! Every electronic device I own does a better job of telling me when the battery is running low! To my knowledge, Toyota has never provided a software update. The information is already there! All it takes is to bring it to the surface where the normal user can see it.
[Stepping of my soapbox.]
After getting a quote for $300 from the auto service center near me; I decided to change my own battery. I called around to find if anyone had a compatible battery as they are not standard 12 volt batteries. Got it at AutoZone for barely more than $200 plus a couple extra tools I needed to get the job done. Next step, change it. Wow! I already knew the 12v battery is in the trunk, but what I didn't know was what was required to dig into the trunk to free the battery. It probably took about an hour in total, partly because I wasn't sure of what I was doing and partly because I woke up feeling very under the weather.