Torque OBD reader shows HV battery charging at 14kw

Knowing the subcode(s) can help when following the workup for DTC P0AA6 : https://attachments.priuschat.com/attachment-files/2018/09/152885_2006_Prius_RM_-_DTC_P0AA6_Inspect_Proc.pdf

 

That shows that your leak is 115 volts from the negative side of the pack. Gen 2 modules leak from small cracks next to the mounting bolts. The hairline cracks form inside the rectangular recesses next to the mounting bolts. They are too small to see. Leaking modules will also leave stains on the case bottom.

Check for voltage between each module terminal, both positive and negative, and a good ground on the case bottom. Leakers should measure close to full module voltage. The leak is opposite the terminal that shows voltage.

This module was charged enough to create a little pressure. A little soapy water shows the source of the leak.

 

Dirty bus bars do not cause a leak.

The sixth module from the right has a stain under it. That's a prime suspect. How does the other side look?

 

The adjoining modules could just have been leaked upon by #6 and be fine.

 

When you say: "cell farthest from the computer side and it shows only .01"
what do you mean by that when your voltage numbers for that module #28 looks normal?

Also are these voltage numbers from a self-discharge test or a load test? They all appear to be relatively normal and when you're using a free harbor freight multi-tester, I'd be more willing to blame that then your pack.

Lastly, it looks like the bus bars were at some point treated chemically in a way that converted the corrosion into some kind of black laminate? Did you do that treatment or is this evidence that previous owner had work done on the pack?

As for bus bar cleaning you can either put them in a rock tumbler for a few days, or you can buy brand new solid nickle bus bars at https://www.reflexconcepts.com/ Or a new wire frame no. 2 for $50 from Toyota will replace one side of your bus bars, as well as replace the voltage sensor wires. Corrosion tends to travel up those wires into the ECU so check that plug for signs of corrosion.

 

Duplicate post deleted...

 

This statement (correct me if I'm wrong) leads me to believe you think the P0AA6 is talking about voltage leaking from a module–in your case being 0.01 V down. Voltage is involved, but it really is talking about physical electrolyte escaping from a module and dripping down to the case, whereby it creates an unintended current path. (This is why strawbrad said to look for staining–the electrolyte stains the case.) This unintended current path creates the voltage leak. So, modules physically leaking are what you should be looking for. Look hard, because the electrolyte is nearly invisible. Once you have found and replaced your leaking modules, you need to remove the modules from the case and clean the modules and the case thoroughly to remove any trace of electrolyte.

I would do this anyway as a matter of course.

 

Yeah I was thinking there seems to be some communication confusion related to voltage leaks vs. electrolyte leaks. Most electrolyte leaks aren't going to have noticeable difference in voltage compared to modules that aren't leaking. Spraying everything down with vinegar and looking for fiizzing or changes in color can help sometimes...

Lastly, the proper rebuilding of a battery pack is not based on finding leaks which is similar, but not the primary focus. The focus is based on the concept of finding the bad cell that caused the pack to fail. There are 6 cells in a module and in most cases 28 modules in a pack and because it's wired up in a series rather than in parallel, that means if just one of the 168 cells in your pack fails, the whole pack fails and you will have to replace and match at least one module / 6 cells to the existing pack.

 

Are you reading close to full module voltage? That's a leak. .1 or .01 volts is not a concern.

It's okay to wash the modules with soap and water. Don't leave them submerged.

 

are all the serial numbers on your modules the same? If they are not it could mean that the leak stains on the chassis were from already replaced modules...

 

If they were original modules, they wouldn't have the same serial number. They would be sequential with the last few digits incrementing.