Driver Door Actuator / 12v Aux Battery Issue?

I have a 2010 Prius with just over 140k miles. So far, this has been a very low-maintenance vehicle.

Last week, I noticed my driver door wouldn't lock with the key fob, driver door / finger thing (exterior), nor the door lock button on the inside of the door. It would lock manually.

I troubleshot this issue a bit using forums online and it seemed to be the door lock actuator. I also saw on some forums that replacing the 12v Aux battery may resolve the issue so I started there.

I replaced the 12v Aux battery as my 2010 Prius had the original 12v Aux battery (manufactured in 2009!), I was pretty impressed it lasted that long. Before I did - I checked it on the display (by pressing and holding the "info" button, putting the vehicle in ACC mode, and turning on/off the headlights 3x). The battery read ~10.8-10.9v. I took my car to a local Autozone where they tested it and their diagnostic tool said to replace it. So, I replaced it with one of their Duralast Platinum Battery. I then drove my vehicle to my hotel and parked it on Wednesday night last week (I'm at training for work). The vehicle sat in the hotel parking lot over the long Thanksgiving weekend.

This morning (Monday), I went to unlock my door and nothing happened. None of the doors unlocked. I used the hard key (please correct my verbiage/term) to open the driver door. The battery was dead. I noticed that the interior dome lights were on but extremely dim. I got a jump (it didn't seem to work on the connection at the fusebox under the hood and I had to go through the back door to the battery itself with the jumper cables as the lift gate wouldn't open since it needed power) and it worked when I connected the jumper cables directly to the battery terminals.

After driving it around a bit, the door now unlocks / locks using the key fob and outside finger lock thing (again - please correct my verbiage / term).

Over the weekend, I ordered a new actuator but am unsure if I even need to replace it.

My hunch as to why the battery was depleted was that the car was trying to lock the driver door all weekend, but don't know much about the subject.

Do you guys have any other ideas as to why the battery died, or if I did anything wrong with any of the above?

Interested to hear your thoughts!

 

Thanks for the reply! What is that? Is it normal to happen on a brand new battery (manufactured a month ago)?

 

All the doors lock / unlock now. The vehicle was in a collision a few years ago when someone ran a stop sign. Front drivers side panels needed replacing.

 

okay. I think have Autozone check it.

 

I’ve noticed (after driving about 50 miles) that my MPG has gone down from ~49 mpg to ~44 mpg. Would this issue be contributing to this?