12V Auxiliary Battery Leaked Acid!

Holy Moly! Just for clarification: this was the original battery?

We are seeing more and more OEM battery fails/threads from the second generation series like yours.

 

Was this a AGM original battery? Hal

 

Id be willing to bet that that wasn't battery acid. A trend I noticed in higher mileage 2nd gen Prius before I left Toyota was water leaking into the rear area. It starts collecting in the 12v well then once that becomes full it will slosh over into the spare tire area. If not drained at that point it will then go underneath the hv battery and end up in the rear floor as happened to our 05. The water is entering thru cracks in the body seam glue where the roof and side Panel meets. If you open your hatch and look in the very top corners at the ends of the black mouldings on the roof id bet you will find some cracks there. Our 05 was also leaking in around the l/r tail light however the body seam glue cracks are very common. I started documenting all the cars that I saw this issue on and sent all the info to Toyota. To my knowledge nothing ever became of it. Id check in that area and see if you have the cracks, if so, seal them up ASAP.

 

First I have seen on this forum.

Yes I agree I doubt that's battery acid. You probably have a cabin leak. If it leaked that much I doubt it would hold a charge. Did you clean off the battery and see where it leaked?
I would go back in the trunk and pull the spare tire out and I bet its wet under there too.

 

I was going to say you could probably smell it in the cabin if you were leaking or maybe it just started recently.

But get out the hose and drown the hatch area seams and lights then check it out and see if its leaking. You need to find that because if you don't the car will get moldy and you'll get sick.
Heard of leaking hatch area many times before but not a leaking AGM.

Let us know. Thanks.

 

Should not be damp should be bone dry in there. You have a cabin leak.

There's lots and lots of posts about hatch leaks please search it as it may help you attack the issue. I do not have personal experience with this issue on a Prius but its pretty common on cars especially around the light gaskets.

And I seem to remember one chatter who had a leak around the wheel well edge that allowed water jnto that battery area. I'm taking on the outside of the car above the rear tire. It was missing something in that area iirc.

Maybe start another post titling a hatch area leak which will draw more focused attention to the issue.Good luck!

 

Hey Boys & Girls! Be careful - Battery acid WILL hurt your skin!

http://www.dekabatteries.com/assets/base/a.pdf

OSH Answers: Batteries

:focus:

 

it finally rained, i checked my battery compartment, and i have water again. so i feel stupid for thinking that was acid. thanks to everybody for setting me straight!

today, i tore the car apart so far that i'm not sure i remember how to get it back together, then it got dark so i have to continue in the morning. i have very good eyesight and can't see any cracks along the hatch seams that others here have found leaking. i have ran water over the back of the car while watching from inside and confirmed water is dripping into the battery compartment. i can see where the water is dripping out of, but can't figure out where the water enters. i will be posting lots of details after i get to the bottom of it.

-ComputerGuy

 

Thanks for the update ComputerGuy (shippj). I hope you can find the leak.

Meanwhile, as Cohnen already mentioned. While rain water is not harmful to your skin, battery acid is! Yes it's dilute enough so that brief contact, particularly to tougher parts like the finger tips, wont hurt (though it's still best to wash it off fairly promptly). Contact to more sensitive patches of skin, like the wrists for example, will result in some painful blistering if it's left there without washing off. Always thoroughly rinse off any skin that comes in contact with battery acid, using lots of fresh water.

 

I found my leak! It was in a place I hadn't seen anybody else post a picture of. The crack was so small it was invisible. It had to be only a few molecules wide (haha). I narrowed it down to an area of 1 square inch by process of elimination with a water hose, and still couldn't see the crack! i have perfect eyesight. i painted over it with touchup paint (3 coats) and hosed it down, and it will not leak anymore. In the picture, it looks like the crack is easily visible, but it's really not. the dark line you see is just a fold of factory silicon or something. the crack is next to it. after i took that pic, i scraped off the silicon and also the bracket that holds the strip down and scrapped lots of factory silicon off because i wanted to see the actual crack but i never did. I can tell you it doesn't leak a drop now, and that's the only place i painted. before painting, water was coming through at at least 1 drop per second. If I hadn't seen this for my own eyes, I would never believe that an invisible crack could leak so much water. It's like there was a space-time wormhole outside that was transporting water to the inside!

 

One can easily taste battery acid or residue, have fresh water on hand and rinse mouth out.

 

Shipj; Really nice posts, many people can benefit from your experience. TY :cheer2:

 

Your not suggesting he should have tasted it are you?

 

Good job ship. What a hassle.

 

Yes! He mentioned PH paper, from the time I was a kid it was not unusual to test a battery, AA, AAA, D cell by touching the tongue to a positive terminal. Would I remove H2SO4 and have a glass, of course NOT. But he already said the acid will not hurt your skin, which I knew was wrong. However had he dipped his finger in what he thought was acid he would have quickly found out that it was something far less then acid, like H20. Should one try this finger test, have a glass of water and soap on hand just in case it is potent, you can also dilute what is on your finger first and if there is any acid content, you will know it.

 

actually i have seen shade tree mechanics around here do the tongue test with battery acid. i wouldn't do that, but i have got it on my skin before, and didn't rinse it off for over an hour, and it didn't hurt me a bit, besides eating holes in my clothes. But i'm not going to argue with the MSDS. better safe than sorry.