i have a 2008 Prius, twice now in the last 3 months It wouldn't start and had to jump the battery in the back trunk. on both occasions I noticed that when I turn the car off it beeps when I open the door but I don't see anything left on. the first time it worked for a couple months but it did it again today. I did check the voltage through the dash and it was 12.6 which was good. any ideas>
You need to check the battery voltage when it has had time to dissipate the surface charge -- odds are it will be below 12v. Better if you had or could borrow a multimeter Meaning, sit several hours and then test the charge. Been through the same drill.... In Alaska, I imagine cold weather is afoot and that does not help matters with batteries.
It is important to check the 12V battery voltage after the vehicle has sat, like overnight. The best way to do this is to leave the hood unlocked and check voltage at the jump points in the main fuse panel. I would also recommend removing the battery and taking it to an auto parts store of your choice for a load test. That will tell the whole story. Do you know how old the battery is? Usually 4-5 years of service is typical.
If the battery initially got discharged perfectly like with a light bulb till it's zero volt it's probably become sulphated and will never hold a proper charge again. Buy a home battery charger and become familiar with your battery's charging behavior. Throw the charger on the battery using the unhood jump points in the fuse box and see how long it takes to go to minimal draw. Do this once a month. It's good for the battery life to be charged to full capacity. All of a sudden you'll see it takes forever to charge. Time for new battery. Do all u can do to not get stranded In Alaska. Buy a new battery. It's beeping at u because a light is on usually because the rear hatch is ajar. Turn the back light off with the switch on the light. Always without exception no matter where u go arm the alarm. It will not allow an arm if light or door ajar especially if u have kids. I arm the car in my garage and have caught light on.
