Hybrid battery Busbar corrosion

Wow, those are fairly bad. Just make sure you've remove the large orange battery disconnect.
Then carefully remove the nuts and plates. Be VERY careful NOT to touch the socket or wrench
between the two contacts that don't have the plate. Which would short the 2 blocks! Not good!

Then wash the nuts and plates in water and baking soda and a toothbrush. Dry them. They maybe
use some fine steel wool to polish up the plates. Re-install them. Make sure you take any photos you
need to make sure you put them back correctly.

 

If your child has a rock tumbler you can put some mild abrasive in the rock tumbler put the bus bars nuts and all that in the tumbler and let it tumble for about an hour when you take them out they will look brand new if you use the right abrasive nothing too heavy then after I reassemble and get everything nice and straight looking good I usually take some of that CRC battery terminal protector red spray it's an oily stuff and I gently go over the bus bars very lightly two times then I close up the case set the battery I have a certain way I put the battery in and the case so I don't have to remove so many nuts and bolts to inspect again and then about every 8 10 months because I do I'll just take a look back there and see if anything is starting again this is actually pretty normal for most of the generation 3s that I've worked on this is what they look like between 75 and 150,000 mi usually by then I'm already thinking about a replacement battery for the Gen 3 anyway so usually I'm getting the replacement rack of cells . And then putting the bus bars and nuts on the new rack spraying it and installing it in the car and so far the latest rack I just sprayed 10 months later looks exactly the same as when I put it in which is a good sign because here in the southeast where I am we have a lot of rain and high humidity so usually this corrosion starts fairly quickly Good luck.

 

I thought torque value for the bus bar hold-down nuts would be in the attached, 3rd gen Repair Manual excerpt, but not seeing it. I'll attach sim from 2nd gen, believe it does have the number.

Yup, it does, one instance on page 73. Note the 48 inch pounds is equiv to 4 foot pounds (you divide by 12). A 1/4" drive torque wrench is appropriate for something like that:

 

Its a DC battery. Just remove it from its connection and clean it. If it was me i would just take it out, dissassemble it, and wire brush it, and put it back in with dielectric grease covering the terminals. But... it looks like it is galvanic corrosion. Maybe if it doesn't clean up well new oem nuts could help. Toyota usually has good hardware much more so than the aftermarket especially their coatings.