Appears to have no power and will not start but battery is charged

Have your 12v battery load tested. If it fails, buy a new one

Make sure all your battery connections are tight, including the ground to body connection

 

Sounds like the 12v battery had gone bad but at a very slow rate. What month year is the battery dated?

 

At least you are in a warm area of the country, cold has brought a lot of Prius batteries to their demise this winter.

 

I'd go with the 12V battery being load tested first, or replaced, before concluding there isn't anything wrong.

 

I had something happened like that. I just bought a used 2015. I drove it around for a while and then parked it. Came back out and tried to fire it up and, nothing. I could tell the battery was down because the inside light was really dim. I freaked because this is my first experience with a Prius. I figured it was something I did out of ignorance. I locked it up for the night and got locked out. Not knowing where the key was. I haven't memorized the manual yet. I went online and discovered the key was in the fob.

I waited until morning and went to jump it with my other car. As soon as I hooked up the cables, the Prius came on. Didn't start the other car to jump it, just hooked up the cables. Don't know why/how. Got inside and the dash looked normal, I suppose, having no Prius experience. Had to reset the clock. It had been in agreement with my watch the previous day. I took that to mean there had been no power to the clock during the time I couldn't start it.

Took it to the Toyota dealer where I bought it to be checked out. Everything appeared to be OK. But it wasn't OK, was it?

 

i would keep an eye on the 12v, once it is drained, it can remain weak.

 

Agree. Dim interior lighting is a dead give away that 12v is low on charge.

 

Sounds like you need a DVOM meter and a wiring diagram to do some voltage drop testing. Do you have an electrical background?

 

I'm having this exact issue on my 2012 Prius C One (has an old school ignition key). Has happened 3x in 3 weeks and appears to be random. Car will be normally driven and parked. Upon returning to the car, the car has all appearances of a dead battery, but upon turning key in the ignition a few times, the display screen flickers to life and then all power comes back as if nothing happened. It is then fine on subsequent drives and parking.
I was wondering if you ever found a solution to your issue as written in 2018. Thank you.

 

have you tested the 12v?

 

12v seems fine - no issues 99% of the time - weird thing is the clock resets every time this happens, but all 12v sourced accessories are fine. After multiple tries of turning ignition key, display flickers back to life and in 5 seconds, all 12v power back as normal and car starts. This appears to be some sort of short in the ignition key switch perhaps.

 

More info as it happened again this morning- check engine light is only light to display on dash as key is turned. Whirring noise comes from inverter while key is turned or in position past accessory. After about a minute of this, dash lights up and all is good. Did not happen again on 4 stop errand run.

 

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This is the only frustrating part with forum threads. An OP starts a thread and gets disappeared never follows up with it.
Obviously he found a solution to his problem since it was over a year ago (or got rid of the car who knows?) but never cared to come here and let us know.
It isn't only this guy. There are a lot that do this and it is the selfishness at its best. It only takes a few minutes to update the thread you have started and let us know how you ended up. It is like paying back the community. Doesn't cost you anything.

 

Once you hang out on here long enough, that will be the least frustrating thing.

 

Ouch... I can only imagine the frustration you have been through the years.
I am not even gonna ask

 

No frustration here, just gathering signature quotes.

 

Had battery tested at Toyota dealership - test showed issues with battery so getting new battery- hope this solves issue

 

bad battery? huh