12v Completely dead

How many amps does your charger deliver? A 2-amp charger might need all day to do the job, and a smaller trickle charger (with skinny wires like a phone charger) is only designed to maintain a fully charged battery. As long as you understand the positive (red) on the charger goes to positive (red) on the battery, it's nearly impossible to make a mistake. The only real confusion is if you are trying to find the Positive jump-start connection that Toyota "conveniently" located in the engine compartment, far from the battery. In a worst-case scenario, many modern chargers will safely warn you and refuse to charge if the leads are reversed. Check the directions.

 

Get a new battery

 

Same here, My 2011 Prius was sitting at dealer for brake parts to arrive for 3.5-4 weeks, and I got a call on the day the parts had arrived and when they started working on my car and let me know that 12V battery is completely dead and wouldn't charge, now they needed a 12V battery to do the brake bleed, I had to go with them and they charged me around 300$ for new battery installed.

After seeing more 12V posts related to battery now after the car has sat for awhile, now I am worried this new battery might go down as well.

Being in an apartment, my options are limited, all I can think is to turn on the car and let it idle for 10-15 mins on a regular basis to avoid this new battery going dead from a conventional car POV,I don't know if this would actually be helpful at all as I have heard these 12V Prius aux battery charge at a slower rate during operation of vehicle than in a conventional car.

Any tips on how to keep battery healthy in this situation would be greatly helpful, don't want to spend another 300$ down the road.

 

battery maintain, 25 bucks on amazon. or just disconnect the 12v neg

 

Nothing can go wrong with a 50 ft extension cord out the front window to a car with engine hood not closed all the way

 

Will leaving the -ve terminal disconnected cause any issues to electrical components in Prius (I have done it my camry and just lost radio and idle rpm, it did re-learn), thanks and sorry being prius noob,.

 

Ha ha true, except climate here in MN has its own mind, will get dinged from apartment manager for sure if they see a wire hanging down from my apartment's window which is at 3rd floor

 

yes, you sometimes lose radio presets, trip meters, windows up and down. nothing major though. don't recall hearing about idle rpm. i disconnected mine for a two month trip to florida, no issues when i got back. you just have to climb in the back to reconnect, or put 12v to the jump point under the hood to use the hatch.

 

Thank you, let me do that, don't wanna pay a another 300$ for a another battery

 

don't blame you.

 

I would have kept the car and deliver it to them once the parts arrived so they can get to work on it ASAP and not leave car for weeks let alone days. They might not even be liable for damages done by thiefs and exterior dings while it sits on their business premises.

Once you get the car back, long as you drive it couple times a week, you don’t have to worry about battery going dead.

 

I agree now, but with brakes completely out, I didn't want to hang to it with brakes being in problematic (actuator/pump going bad) during this crisis if I need to go get something for my family,