What's your 12v battery resting voltage?

The statements wording of English doesn't even make sense even as poor as my English might be something about the resting rate is normal for a Prius hybrid vehicle versus other hybrid vehicles yeah okay whatever I know in my vote which is another hybrid vehicle unlike the Prius not the same kind hybrid synergy drive or whatever and I don't see anything about its 12 volt resting voltage being below 12 volt I measure at the battery I don't care what it is after it comes down the pipeline through all the wiring I expect them one volt voltage drop pretty easily I would imagine but what it's sitting in the back of the car and it's fully charged state resting state after charging whatever you want to call it needs to be 12 volts now what the car sees after it comes down the line I'm not sure if that's a bad thing or not as long as it stays right at 12 volt 11.9 etc problems generally aren't supposed to develop until we have a full voltage dropper better You see things talked about it 10 volts and 9 point something volts and so on Not in the Prius but in other 12 volt systems My car used to start a regular starter with 10 and 1/2 volts in the battery according to the fancy expensive test meter.

 

12.7v since 10 years /

 

is it an agm battery? mine was always around 12.7 in the morning, until it croaked

 

Only two problems you have is: 1) mechanic who thinks 11.9volts is normal is an idiot and that 2) Prius have a really weak charging system for 12volt batteries and over time you need occasionally put the 12v on a real battery charger, preferably a smart charger that goes up as high as 10amps.

Also make sure there's no light on the dash indicating a door is open when you're not driving.

 

12V + at terminals If you lose close to a volt running through the car that wouldn't make me panic too much as long as I have my 12.5 12.3 whatever it is back there at the battery resting charge should be fine Is there something wrong?

 

When the fancy tester goes on the battery that's doing this 11.9 does it fail to load test well if so then they'll take care of it and get you another battery I imagine If it fails the load test on the $30,000 battery machine then probably something's wrong with the battery If it passes the load test I would think it should be reasonably good to go especially in a Prius as there's no starter or anything to do all that does is turn on low voltage computers if you will and headlights if you're got halogens in that's quite a load on the battery at night especially if you're one of those that sit in the parking lot with your lights on while you're doing whatever in the car and the air conditioner running and all that I know the air conditioner is not running the 12 volt but the fan and all that is

 

What shows on the display is after things have started up, and before the hybrid system
starts up.
You HAVE To check the actual 12v Battery in the trunk, BEFORE opening the drivers door.
So you leave it unlocked so you can get the trunk open to check the voltage AT the battery.
at 12.5, it's questional.
This statement is not correct, 11.9 is NOT normal, for a Prius.
"Resting voltage of 11.9 is completely normal on a hybrid vehicle as compared to other hybrid models"

 

do you drive much? because of the poor charging system, and the normal draw when the car is off, limited driving will not keep the battery up to snuff.
if that is the case, a battery maintainer is a good idea when you are home.

 

Prius is not meant to charge AGM battery's. AGM battery's require a different charge protocol.

 

The OEM 12v auxiliary battery for North America Gen 3 Prius is an AGM battery. So, the car is designed to charge an AGM battery. I do not know where you are getting your information.

 

I've never seen ours under 12.7, more typically 12.8~12.85. That's non-cheating volts, never just after charging. It's an Optima Yellow Top. With our infrequent use I keep it on a smart charger pretty much constantly. Installed September of 2015.

(* Apparently not the best choice, higher CCA but but lower Amp Hours; I'll likely try something else when it's time again.)