Got an issue here and can't find others that seem to have the same issue. oh, and I checked the voltage of my battery after sitting for 6 hours and it was 12.3 (through the diagnostic screen). The battery is only about a 1.5 years old. So here is the issue that i've been having... A couple times I go to start the car and and the dashboard lights turn on and off, the brake pedal feels like the hydraulic turns on and then off (with the lights) and it just cycles like this, unless you turn it off. Sometimes it starts after a few cycles. A couple days ago I tried starting it and the check engine light came on (but no other lights). Then after trying a few more times the lights came on, but almost like acc mode (wouldn't let you put the car in drive). Then after trying more the gas gage went up to full and started blinking, as well as boxes around the drive, park, B icons on the dash (almost like the computer was reseting). The battery seemed low, but after a few minutes it started up fine, and drove home. Since then I've had the first issue return where it feels like the car is turning on, off, on, off. Does anyone have any ideas? Thanks Dan
It sounds like your 12V battery is in need of replacement: Entering Maintenance Mode (aka 12V Battery Check) without Switching Headlights ON/OFF | PriusChat How old is it? If possible put a charger/battery maintainer on it to keep it alive.
Even though your 12v is not too old, if it's been discharged a few times that can weaken it in cold weather. I would ask what kind 12v it is? Lots of us like to use Optima Yellow top which is a little more forgiving to deep discharges. Also the 12v charges up kind of slowly in the hybrid system. So if your 12v batt is low you need a fairly long trip to charge it completely. That's why some like to use a battery charger on it, but I have not done so myself.
yeah, it's one of the Optima Yellow tops. My 1 hour (each way) commute must not be doing enough for it. How often do you trickle charge it? Once a week? daily? Could this be an alternator issue? Cause I haven't knowingly drained it...unless leaving the lights on for 15 minutes would drain it all the way down. Thanks for the help
One hour commute ought to do the job, one would think. The SKS system can drain if sit car for week+ at a time but sounds like you use it daily..
The Prius has no alternator. The 12V charging is done via the converter from the HV system. Please do the test above and report what the three voltages are, so we can be certain that the converter is working. How old is the battery? I would make sure the battery is completely fully charged at least once a week.
The Prius has no alternator. The 12V charging is done via the converter from the HV system. Please do the test above and report what the three voltages are, so we can be certain that the converter is working. How old is the battery? I would make sure the battery is completely fully charged at least once a week.
To me it sounds like your "Yellow Top" is failing. It is not common for this battery to fail this early, but you do have the symptoms of a weak battery. If I were you I would run the test with the MFD again and post all three voltages. 12.3 is a little low, but depending on where the 12.3 was read in the test could tell a lot of things. The more important value is when the test is at the ignition on mode and finally the ready mode. If we knew what all three value were, we could better tell if the battery is weak, discharged or the DC to DC converter is not working properly. With all that said, please post all three values Accessory Mode? Ignition On Mode? Ready Mode? DO-IT-YOURSELF TEST PROCEDURE (thanks to jdenenberg): - Without brake pedal, press the Power button once and release to enter ACC mode - Press and hold the MFD Info button, then turn the headlights on and off three times to enter Maintenance mode; release Info button - Press “Menu” (on screen) - Press “Display Check” - Press “Vehicle Signal Check” - the battery voltage is shown and should be about 12.4 to 12.8 Volts (normal for an unloaded battery) - Again without brake pedal, press Power button and release to put a current load on the battery - the voltage should stay above 12.0V (if less than 12.0V the battery is not well, or there is a fault or unusual load somewhere) - Press brake pedal and press Power button once to enter "Ready" mode - the battery is now charging at about 14V (if less than 13.6V or more than 14.4 there may be a problem with the charging circuit) - Turn car OFF to leave Maintenance mode
So, sounds like the ign on mode is low...but I would think a battery that has been in for 1.5 years should last longer, if I'm driving it consistantly (4 days a week for 1.5 to 2 hours, and 3 days just short trips around town). I'm not the original owner, but pretty sure the original battery was in until 2009, when I got it.
You could try an overnight charge and test it again in a couple of days. If it drops back to your current readings then it is time for replacement.
The IGN voltage number is not all that low, and it could be more about cold than age. Perhaps take a look at the battery connections and make sure they are tight, as well as the connection to the car body. Trickle charging is still a good idea, although it does look like it should be a little better given your drive time.
I would suggest what jdcollins5 said, charge the battery fully with a "smart" charger. Then test it again after it has set a while. I have a feeling in the end you will be installing a new battery. Best of luck to you.
I just got a new(?) battery Optima from Specializing in: dictionaries including the Collins Cobuild, Oxford English Dictionary (OED), Webster's & Random House. auto parts, study skills and life improvement and I did the test above listed by dorunron here Prius startup issues | PriusChat and these are the scores I got: Accessory 12.2 Ignition On 12 then 11.9 then 12 Ready 14 I did this 1st thing in the morning after car sat all night in 50 degree weather. Also when I tried to enter Accessory mode the radio came on - is that right? or did I enter an incorrect mode? If this is right is it a bad battery? FYI I am also posting to another thread - 12v battery replacement cost | Page 3 | PriusChat hope that is OK.
