HV battery issues

Hi Folks. I have a 2006 Prius that's presenting code P0A80. I took the battery out, cleaned up the pieces in the bus bars and checked out the modules. I'm new to this but have picked up quite a lot from the wealth of knowledge available on this site. I can't afford a new battery at this time so, I hope to rebuild the pack myself.

I tested voltage on the modules with no load and then with a load. I used a sealed 55w/65w headlamp with a light switch to load test for 1 minute.
Here are my results.
Module - No Load -- Load -- Variance
1----------- 7.42 --------7.18-----.24
2----------- 7.59 --------7.28-----.31
3----------- 7.45 --------7.18-----.27
4----------- 7.60 --------7.27-----.33
5----------- 7.46 --------7.18-----.28
6----------- 7.59 --------7.25----.34
7----------- 6.13 --------5.71----.42 *
8----------- 7.60 --------7.26----.34
9----------- 7.45 --------7.16----.29
10--------- 7.59 ------- 7.26----.33
11--------- 7.30 -------- 6.84----.46 *
12--------- 7.58 ---------7.24----.34
13 -------- 7.42 ---------7.14----.28
14 -------- 7.59 ---------7.25----.34
15 -------- 7.43 ---------7.14----.29
16 -------- 7.59 ---------7.25----.34
17 ---------7.44 ---------7.16----.28
18 -------- 7.59 ---------7.25 ---.34
19 -------- 7.44 ---------7.16 ---.28
20 -------- 6.32 ---------5.81 ---.51 *
21 -------- 7.45 ---------7.18 ---.27
22 -------- 7.59 ---------7.26 ---.33
23 -------- 7.47 ---------7.20----.27
24 -------- 7.60 ---------7.28 ---.32
25 -------- 7.47 ---------7.20 ---.27
26 -------- 7.59 ---------7.28 ---.31
27 -------- 7.48 ---------7.23 ---.25
28 -------- 7.55 -------- 7.25 ---.30

It looks, to me, like 7, 11 and 20 are bad. If anyone disagrees, please let me know.

My plan is to replace bad modules and use get the grid charger from Hybrid Automotive to balance the pack. I know some are using the multiple charger technique for balancing. The grid charger seems to be the way to go, for me, because it sounds like a simpler approach and I will have it around for ongoing preventative
maintenance.

I have a few questions though.
1. If 3 modules are bad, should I replace 3 or 4? I've heard to replace in pairs and wasn't sure how that would affect this situation. It seems that I'd be trashing a somewhat healthy 4th module.
2. Should I shuffle the modules around? I've read that this is a good idea but there are various opinions about how to set them up. I've read to keep blocks of 2 with similar voltage or to swap the inside modules with the outside modules. Should I use an amalgamation of the two methods?
3. I've read ericbecky say that the replaced modules should match capacity or resistance(or something else, I can't remember) to the ones in the pack. If I'm balancing with the grid charger, is this important?
4. Jeff652, I hope you see this. I want to get the discharger. Can you describe the difference between your simple discharger and the forthcoming advanced model and how it works in conjunction with the charger? And do you have a solid release date for the advanced model? It sounds close. I may benefit from it but need the whole setup asap. I haven't ordered anything yet.
5. I'd like to observe the ongoing condition of the battery, also the ability to diagnose issues with the car. I have been looking at elm327 devices but there is so much info flying about that I'm a bit confused as to what I need. If possible, I'd like to use bluetooth and all my laptops are win8 (god help me). So, Mini vci is out. I'd like a scan tool that is basically plug and play but will give block voltage readings. What do you think about ScanTool's OBDLink LX bluetooth scanner with the addition of priidash?

Thanks

 

If you see this, Jeff652, Can you please also give me a rundown of what the programmable wifi integration will give us? I don't see much on your site in regards to this interesting prospect.

 

Thanks Jeff. It appears that I was submitting an order for your charger and discharger as you were typing your response.
I also ordered 3 modules from ericbecky. My hopes are high that this will get me on the road. The resources on this site are nothing short of incredible.
Thanks, everybody, for your help and input.
Hey Jeff, I wonder if you'll ever produce a combined charger/discharger for those that will be starting from scratch.

 

With Eric's help, I've got good replacement modules and have the pack together and installed.
Jeff, I'm on a learning curve with your charger and discharger. I had expected the voltage to top out at 240. I was away for a bit so, wasn't able to follow the charge closely, at all times. But I did notice it get to 239. Then, it came down and seemed to want to stay at 235.
After about 24 hours, I pulled the plug to focus on discharge. I got the 200, 60 and 15 watt bulbs. Took a bit of looking because some were called replacement bulbs and actual wattage was less. Most of the 60 watts actually used 43 watts. If I understand your site's guide, it can take less than 4 hours to discharge. I think it took about 2 hours just to get to 196 volts. And maybe about 6 more hours to get to 140v. I understand that every pack is different but just wanted to run this by you to see if this is an odd situation. I have noticed a jump back up in voltage after inserting the next set of bulbs. Maybe 10 volts. Now that I'm using the 15 watt bulbs, I'm not really sure how low to take the pack. I think you've mentioned .68v per cell as being the minimum for measurable impact. I assume you mean around 115v for the pack? 115v divided by 168 cells being .68v. Is that how to figure the individual cell voltage in relation to the pack?
If I'm on the right track, I assume I'll do this 3 times, finishing with a 4th charge. What's a good step down voltage for the next 2 discharges?
Thanks

 

After about a 11 hour discharge, I think it's complete. With my target of 115v, the last few volts went quickly and I stopped at 114.3v. I plugged the charger back in. The cooling fan control sub-assembly seemed to run with a high pitch for 5 seconds or so, then went silent for a few seconds, then started back up with a steady but lower pitch. I think the battery fan ran steadily during this episode.
I noticed the voltage on the charger started out at about 125, then, within a few minutes, hovered around 150 but moved around a lot between 144 and 152. Back and forth. All this time, the mA would swing wildly from around 360 to 0 and back again. Is everything as it should be?
Now, about 10 minutes later, the voltage is reading just under 200 and moving very slowly. The mA are fluctuating between 120 and 300 with an occasional 400.

 

Yes. It's at 233. It has been increasing 1 volt an hour, for the last 3 hours that I have been able to pay attention. It has been almost 12 hours on this charging cycle. Should I let it go the full 24 hours to be sure of balance?
thanks

 

You guys are awesome! After 3 charge/discharge cycles, with 1 more charge to top it off, I've gone about 400 miles without HV codes. Now, I do have codes P1121 and P1116. So, my next task is to address the cooling system. HA!
Always a new adventure.