I have a 2009 prius with 164,000 never had any problems wit hit at all. But today i left work to go to lunch and when i got in my car to crank it the dash was blank, I hit the power button anyway and nothing happened. It was like it didnt even have a 12 volt battery in it. as i looked at the dash closer i noticed the check engine light showing very dim. i got out and opened the hood and could here some faint clicking noises. so i figured the battery had gone bad. I took my work truck to lunch and when i came back my car was sitting there running and radio playing like nothing was ever wrong! I don't get it? I checked the battery and it is fine, it is cranking and running fine now, can someone explain this one?
How, exactly, did you check the battery? Battery checks are done first thing in the morning, after not using it overnight. Did you also check for loose battery connections?
Sounds like it's time for a new 12v battery. Just to be clear, the 12 volt doesn't crank anything. It just powers up the computer. Why it was running when you got back from lunch is a mystery to me. But once it was running, it would charge the 12V. You need to check it with a volt meter with and without a load and the car shut off. Might want to check again with the car running to make sure the charging system is OK, but that probably won't tell you much about the battery itself.
I checked it by hitting the power switch, holding down the display button and turning the light switch 3 times way, even with the car running it was showing 14.4 volts after running a few minuts
14.4 volts just means the car is charging it properly. you don't have to pull the battery, just put a volt meter on the jump point under the hood.
14.4 volts is the voltage that is charging your battery, not the voltage of your battery. Let it charge for a couple hours, it just needs to be ready, you don't need to drive it. (be sure it has enough gas) And check to be sure the cables are tight at each end, it may be the connection, not the battery.
You don't need to pull the battery to check it just open the hood and take the cover off the black fuse box and under the red plastic cover is the 12 volt positive jump point. Test across that point and chassis with a volt meter first thing in the am before you start the car. That will give you its resting charge. I'm guessing its around 11 volts. The car has probably been flashing the red exclamation point upon boot up too . Only flashes it for a second on the dash then goes away. That's the only warning it will give you your 12 volt battery is crap.
Turn on car the pull fuses in bank c then turn off install fues in the right spots Posted via the PriusChat mobile app.
I had two Prius do this and it stayed fix in both been years It will sync computers Posted via the PriusChat mobile app.
You can check the 12 volts at the cigarette lighter with the car off Posted via the PriusChat mobile app.
It takes less than a minute to pop the hood and the cover over the fuse box and put a meter on the positive terminal and a bare bolt or nut.. As several others said, do it with the car off. Otherwise, you're testing the charging system, not the battery.
