The Tangled Web of Traction Battery Repair That Tortures Me

I had a traction battery module blow out and vent into the cabin with that characteristic "electric gas" about 10 minutes after a Dr. Prius life expectancy test. Heard a loud "pop" and had a pretty good idea of what happened. In fairness, my 2006 Prius with nearly 200K was already limping a bit from multiple dying modules including the pair at position 13 where the blown module was eventually found and at position 12. So after the module eruption, the car was still able to limp home and the car was also still able to start so that I could reposition it for repair a day later.

IMPORTANT---The car still started before I started working on it 24 hours later, even with the exploded module.

So I replaced the bad modules with 4 deep cycled modules at 12 and 13. I did not recondition my other modules before reinstalling the traction battery. All nuts are well torqued. I should mention that all the non replaced modules measured from 7.56 to 8.04 an hour after removing it from the car about 90 minutes after the car was running. So not letting the modules fully drain was just my first mistake because when I tried to start the car a week later (after replacing the 4 modules at positions 12 & 13), I got the voltage leak code of P0ADC-226 and measured 5 modules in the suspected positions at less than 7.1. The first Dr. Prius pic below shows where those bad modules resided. I, unfortunately, did not capture the pic of my pre-repair battery status but did capture the first Dr. Prius pic shown below (which was after replacing 12 & 13). All dash lights came on, including virtually every warning light, but when shifting into gear it went only into neutral and the ICE did not start. 12v is fine.

So I removed the battery pack and replaced 6 more modules so that none measured below 7.59V. Then tried again to start the car, and like the first 2 times, plenty of warning lights and good 12v power, but check out the second Dr. Prius pic below. Does anybody know what I did wrong here? P0ADC-226 is still the only code. I checked all connections, and yes, the orange safety plug was clamped and pushed down. What is that 2nd picture telling you, please? Does Dr. Prius have a place where these patterns are diagnosed? Frustrated. Thanks in advance for your help. And don't forget to respond to the poll.

Here is the Dr. Prius reading before installing the 3 pairs of modules and the 2nd image is the Dr. Prius reading after reinstalling the traction battery (refreshed with 6 additional deep cycled modules) and attempting an obviously failed restart. Are the consistent 19.0 milli-ohm readings on all modules on both Dr. Prius pics telling in any way? Help, Please! Happy Holiday for whatever you celebrate.

 

Don't it, though. Very symmetric and kind of an existential allegory the way it graphs out the ups and downs of life

 

When you say hundreds of connections, I only count 56 terminal connections. Unless there are more than one connection at each terminal that I don't understand.

And yes to the Orange safety plug question, though I did forget it at first. Interestingly, the weird Dr. Prius graph is the same with the plug connected as when not correctly installed and fixed into place. Weirder and weirder.

 

I thought the same and they are all installed correctly. It's hard to install the modules backward without being suddenly stopped as you try to connect the cooling tubing. You would be alerted to the mistake immediately. Just a bizarre reading that I am sure somebody has seen before. I know it is likely a simple fix but I don't know just what needs fixin'.

 

Thanks TMR, I'll do that. This car never resided outside of arid California so corrosion is not an issue, but maybe the PC savants will notice something that is amiss.

 

Yeah, there are no voltage readings on the 2nd chart and you can see that no voltage is being read by looking at the pack voltage...near zero. I'll recheck the grounding strap in the morning too. Thanks again.

Also, do you know what the red bar on Block 11 means. Is that a bad block even though it has low-normal voltage?