2009 Prius 12v Battery Drain?

Hi!

It's been a while! This week Prius seemed to get stuck in accessory mode once when turning on. The brake, triangle, door and a few other dash lights were on but car wouldn't start. When I pressed power button again there was no response from it except that the orange light was still on. I don't even remember what I did to get the power button to respond. I think I put the fob in the ignition and was able to shut it off. Then everything worked fine for a few days.

Tonight I tried stating car while running errands and the same thing happened again. This time I put fob in ignition and it didn't do anything and then I couldn't remove it. I panicked (as usual) and called dealership since they were closing. Manager told me to press the power button for 15 seconds. This shut the car off completely. I was able to remove fob but car wouldn't start and acted like battery was low/dead. AAA was able to charge batter and with in a few minutes said battery was 3/4 charged. When car turned on the info display said something about the transmission which totally freaked me out. I'm hoping this was just because the battery had drained and electrical stuff was rebooting.

I do recall hearing a door alarm going off at different times over past couple of weeks when I exit car. I searched to be sure everything was shut off. It's an alarm that sounds like the one when lights are left on but I have lights set on auto. Could I have switched something on by accident that could be draining the battery? What kinds of things can drain battery besides the usual headlights or cabin lights? It was dark and no lights had been left on. If a door wasn't closed properly, I wouldn't have been able to lock the car.

Any ideas? Maybe a faulty battery? I was reading on here that a battery can test that it's ok but still need to be replaced.

Car has 145,000 miles on it. When I look at hybrid battery functions on display everything seems to be charging well.

I'm calling dealer in the morning and having them check battery as well as codes.

Long winded worrier...sorry.

Thanks,
Maria

 

Thanks so much for responding. I was just reading through a bunch of posts and saw someone with the identical issue even the same transmission error. He described the same door alarm sound too. Wish he had followed up with results.

My hatch back area is filled with books etc to be donated and now realizing the battery is buried underneath all of this. : /

Battery was last replaced 11/2014 so it's sounds like it's about time anyway.

Hoping I can have them replace battery and pull codes. Hopefully won't be charged $100 diagnostic fee on top of all this.

Thanks again!

 

Thank you so much for all the responses. Dealer was able to fit me in first thing this morning.

Battery tested at 6 volts. They also checked for any codes without charging me $100 diagnostic fee. Service manager didn't want me driving off with a hidden issue beyond the battery. He agreed codes would have cleared if battery had died but last night (before AAA charge) cabin lights were still working. He felt confident there weren't any engine codes erased. Replaced battery for total of $291. So far I'm only a DIYer with cabin filter, engine filter and windshield wipers. : }

I'm thinking maybe the hatch back was shut enough to keep the warning light off and possibly draining battery. Trying not to beat myself up since the battery was 4 yrs old.

After all that I read last night.......I'm thinking way too much about the hybrid battery. : / It was checked last year. No symptoms and display shows all is working fine. I'm finally beyond the warranty which makes me very nervous knowing life expectancy is about 10 yrs.

I'm flashing back to when all of you guys, so generous with your time, helped me maneuver the purchase of this wonderful car. It came with the confidence of a few more years of 150,000/10 yr hybrid warranty. I was hoping hybrid battery would fail during the warranty period. No such luck.

Now that it's 2019 what are the most reliable options for replacing hybrid battery? If it ever goes, I want to be prepared as possible since these decisions usually need to be made quickly. My plan was to drive the car until there's a problem. I eventually want to trade up to a 2014/15. I guess trade in value now verses trade in value when hybrid system dies is irrelevant unless funds appear.

I do love my 2009 Pria as she is! I remember test driving a 2010 and it wasn't as much fun to drive.

Thanks again for your thoughts and suggestions.

Maria

 

Thanks, Bisco!