2010 Prius, found a lot of water in the spare tire well/compartment after a very wet California winter. Apparently, this is a known issue as there are 2 drain plugs to drain the water but it's less than ideal to keep having to drain it after a rainstorm. I didn't see water in the 12V battery or on the sides though, it's just in the spare tire well. Based on my search here and online, it seems like these 2 places (circled in red in the pic) are the main culprits for Gen 3 Prius, has anyone had this issue before for a 2010 and fixed it? Thanks.
I just removed some plugs so the water could just pass through when it does get in I keep that track pretty clean back there I don't let dirt bull crap and all that get in there and so far I've had it dry trunk I had the battery well almost full and then I took care of that by putting some strategic holes for water to drain and I don't really see where it's getting in but I keep watching
I just woke up to this after a heavy rain, for the first time ever in my 2010. The spare tire well had about a pint of water in the bottom. I would love to know the best way to resolve this while I’ve got the entire back seat and traction battery removed.
It's usually coming from around the area where the door hatch seal mounts to that little lip that sticks up If you go around that area with a flashlight and look really well for any cracks where them folded metal is actually glued together kind of like a fish tank but this is sheet metal that you can't see through but it's very similar as far as the glue job goes water tends to get where this glue job starts to crack If you don't see any of that all the way around the hatch then you need to be looking at your hat seal which generally speaking should not be leaking if it's attached properly seated on the lip all the way around the hole etc etc You should also or I take the plugs out in the areas of the spare tire well there's two I remove one of the two directly under the spare over in each corner of the trunk under those storage areas and behind the battery there are another one or two rubber plugs I just reached my screwdriver and push them out and then I drilled a few more holes around in the battery tray to make water fall out of there quicker because at some point it will get in and rather than have it freeze and fill up halfway around the battery He might as well have the drain holes open so water can pass through before it turns to ice and get solid that's always seems to work pretty well for me anyway.
hard to tell where on the car your picture is, but the main culprits are cracks in the gutter seam under the black plastic trim, the hatch door hinges or gasket, and even the tail lights
You may not have water surrounding the battery now, but, in my experience, you will if leaves, pollen, and other tree debris clog the drain passage that passes between the taillight and the body. I had to take the taillight off and clean it out to stop the leak. I haven't had leaks into the spare tire area yet.