A question about voltages

Yes.

Load test them.

 

Not particularly. You can’t really glean too much from an open current voltage (OCV) test. You may spot a module with one or more failed cells as it will be 1.2 V ( or a multiple thereof) lower than the rest.

As suggested by edthefox5, a load test of all the modules will be more productive and tell you more about each module.

Once you weed out all the weak modules and then find suitable replacements (that match with the remaining modules), you will need to do some charge/discharge cycles to balance all the cells within each module. Follow that with a final charge.

 

The end modules tend to run a tenth of a volt under the rest. So module 28 is not showing unusual voltage but module 1 is 2 tenths below the rest. Number 8 looks suspect being well above the rest. As others have said you need to load test the modules.

Too bad you already took your battery apart. It's just so easy to test the batteries while they are still in the car. All that is required is a $20 bluetooth OBDII reader and a free Android app. Torque is one that will work. Hybrid Assistant and Hybrid Reporter are just amazing.

Here is just a small portion of what Hybrid Reporter can show. In this battery block six contains the failed module.

 

Sometimes that is all it takes.

It would still be a good idea to get something like Hybrid Assistant and Hybrid Reporter (plus a compatible OBDII dongle) so you can monitor while driving. Maybe a grid charger is in your future too.

Good luck with the repair and long may it last.

Feel free to pop back from time to time and update how things are going.

 

It's time to order a Elm 327 Bluetooth code reader. You will need it soon!

 

Check out my experiences in my signature. It might help clear up some things.

GOOD LUCK!

 

Sorry to be the bringer of bad news but P0A80 indicates a cell failure within the battery pack. What you did is essentially clearing the codes and reset the battery state of charge. The failure will come back, get a code scanner like strawbrad said run the app he suggested. Once a battery module experiences a failure it will keep coming back even though it might take a charge at first (like yours has).

 

Cleaning the buss bars was likely part of the issue but make sure you also load test all the modules especially since someone else was already in there and you have no idea if they did the rebuild work properly. At least that way you'll know what you have and can maximize the MPG on your Prius once more.

 

Will this set up allow other diagnositics to be conducted, or only on the battery? Does it gather the same information as Techstream?

 

It will read/scan Engine Control Module for stored/pending/current codes on all makes and models (1996 and up), with custom PIDs loaded (google search: prius PIDs torque) it will give you the same data as techstream, including battery block voltages and so much more.