What is this part?

Looks to me like what sits over the 12-volt battery in the aft starboard corner of the car.

 

Looks like it fits over the 12v battery or the similar opening on the left.

 

duplicate

 

Looks like someone separated it from the flat carpeted piece that attaches on top of it. Me, I always just take mine out as one piece. I haven't unclipped the top piece from it.

Did they just sort of put the top piece back over your 12-volt battery, hanging by the edges?

Do you have a non-original-size-shape battery back there, that this support piece won't fit over?

Or does 2012 just have one wide deck board all the way across, instead of separate pieces in those corners like my 2010?

 

Our 2012 v Five has no such aux battery cover.

 

Hmm, interesting. This is the Prius v forum, but the OP just says a 2012 Prius.

 

maybe they left someone else's part in there.

 

It's the right shape to fit into the rear fender well.
What fits into it, I don't know.

 

Looking up the part number might help...

 

The one in my 2010 liftback looks very much like that (from memory, I haven't run out just now to bring it in or take photos). OP's first photo shows its normal orientation. Third photo shows it upside down, looking at its black-felt-covered 'feet'. The tall feet on the inboard edge rest on the hatch floor sheet metal. The shorter feet rest on the top of the 12-volt battery.

The notched tops of the 'buttresses' along the inboard edge support the lip of the big black cargo tray (so, the cargo tray must be taken out first, or at least lifted, before this battery cover can come out).

The one in my car is topped with a flat carpeted piece, missing in the OP's photos, of matching height with the carpeted deck board that lies over the cargo tray and serves as the carpeted bottom of the hatch area.

I might have to go look more closely at mine to be sure whether the flat carpeted piece can be removed (if it can, I've never done it), leaving the substructure as above, or it's really just a single piece in my 2010, as I have always thought.

Nah, being too lazy to stand up and go out to the car ... screenshotting the 2010 and 2012 Prius owners' manuals side-by-side shows they did change it: one piece on the left (2010), "deck board" plus "battery cover" on the right (2012).




When I added some fuses and stuff above the battery in my 2010, I did have to pay a bit of attention to not having my added stuff be right where those short felt-padded feet sit on the top of the battery.

 

Nothing like this in the v…

 

May look into one though, as a positional spacer for the aux battery compartment.

 

The photo with the fuses was from my car, where I added the fuses. They're not stock. It went with the part where I said when I added the fuses, I had to be careful not to have anything right where the felt-tipped feet of that part have to sit flat on top of the battery.

 

I use my 12V sockets a lot. Charging my phone, drones etc., but I never know how much total draw can happen. That's why I installed circuit breakers in place of the fuses in both my sockets; one switched and one live.

 

Originally for an inverter and an air compressor, and a general-purpose 12V circuit that doesn't shut off right away with the car, and later a fridge connection for when that's in the car.