2005 Toyota Prius-Rebuilding hybrid battery having issues

i don't understand if you take the safety plug out, fix & reinstall the battery and then put the safety plug back in how would you even see the sparks as they would be hidden inside the case?

Some loose connection somewhere so maybe do resistance test with multimeter. I would also test the case make sure not live voltage running through it somehow.

 

Polarity of one or more cells

 

Check cells + - of all in pack one or more is in the wrong order

 

Maybe this will help. This is a photo of a battery pack I'm doing some testing on. The temperature sensors are still installed and the modules have never been removed from the clamps. Its easy to see how the modules should be oriented starting from the CPU end.

 

I would recommend removing all connections along the battery set (positive and negative connectors), remove copper connectors from the plastic strip where possible and soak in Bar Keepers Friend Lime and Rust Remover Extra Strength (like TarnX but better for this job). Also sand with emery paper any connection and sensing wire terminal ends that don't come clean with the Bar Keepers Friend. Reassemble all connections only when they are all shiny. Sparking is coming from bad connections caused by leaking electrolyte. Once all the bad connections and bad cells are corrected, use a Prolong (see Hybridautomotive.com) battery conditioner to perform a balancing charge on the whole battery. I know these work because I just purchased one and used it on my 2007 successfully. Of course there could be other problems with controlling circuits, relays and computer controls but I think those are normally pretty bullet proof.

 

I had sparks once and thought it to be my fault until i investigated and found the thin voltage monitoring wire going to the battery control computer in the battery box had been compromised with battery corrosion all the way to the computer. It shorted out inside the connector and burned a few pins off the computer. After replacing the computer and harness all was good.

 

thanks for the update! congrats, all the best!

 

I experienced some arching today when mounting cleaned bus bars on the battery pack.

The battery had now completed a full charge using the prolong (each module reading 8.2 volts). When I cleaned the bus bars and reinstalling it, sparks happened and damaged the battery terminal (see image).

some say do not reinstall together but rather one at a time and some say it’s ok to install all at once.

 

Did you remove the safety switch? There should be no arcing anywhere in that battery.

 

I am trying to figure out how you could have any sparks or arcing when "reinstalling the bus bars". Did you get the modules or bars in the incorrect order and ended up shorting a pair of modules (ie. you had both ends of two modules connected to each other)?
Even if the HV ecu had shorted internally while you were cleaning the bus bars, I don't expect that such a fault would cause the damage to that module stud before the ecu or wiring failed.

Posted via the PriusChat mobile app.

 

as @mr_guy_mann mentioned....sounds like you looped the modules. Instead of 28 modules in series, you tried to make (14) 2 module loops. One side of your modules likely has the busbars out of position by one module. Or, you just touched them while it was misaligned by one spot.

Amazing what electricity can do. One reason I always install the wire frame #2 harness first. Then the other side busbars, starting from the outside terminals.

 

yes I did remove the safety switch.