Buss Bars, clean or replace

They are available from toyota.

Use the search forum link up top and search hybrid battery there have been a few posts I have seen that posted the part number and other methodology
To clean the interconnect.

Also important to remove all plugs from the ecu which is the slim metal box next to the battery’s. Look closely in the plug socket and plug itself with magnify glass and look for corrosion. Take the ecu out take it’s covers off and look for micro corrosion in there too very very common.

There are hundreds and hundreds of batteryrebuild threads on this site spend some time reading them via the search forum link it will really help.

 

There's several businesses who sell aftermarket bus bars for Prius. The solid nickel ones are nice... The easiest way to clean your existing ones is the put them in a rock tumbler for a day or so. Also the side of the pack that has voltage sensing wires is a part known as "Wire Frame No.2" and in the US Toyota sells them for $50 and they come with brand new bus bars, but only for one side of the pack.