Here we go again. A forum member "J" with a 2007 Prius was having some battery problems. We worked out a deal for a Gen 2 battery built using low mileage 2016 modules and installed it November 24th, the day after Thanksgiving. The information in this post is directly from the battery we removed from his car. "J", if you happen to read this thread, please feel free to add any information describing symptoms you were experiencing or anything you feel like adding. To start, we're going to call this battery "Battery J". It was a "warranty seals intact" Greentecauto Gen 2 battery. The 18 month warranty version. I want to use this battery to showcase capacity variations between modules of a used battery/rebuilt battery, and how a voltage reading alone cannot be used to determine if a module is good or bad. Right from the start, I want to say the battery lasted approximately one month past the 18 month warranty period. In that sense, the battery met it's expected life. I'm not going to say anything about it one way or the other. It is what it is. The owner was experiencing the P0A80 code but with no "module x becomes weak" code and had noted significant performance reduction. The first thing we noticed during removal was an area of significant corrosion over the width of 9 modules. It basically extended from block 6 through block 10 with the worst of it around block 7/8. Very indicative of a module leak, so the initial assumption was an intermittent HV isolation fault. Based on the corrosion visible on the case, under the case on the module fasteners and in the air plenum, I just assumed it was probably a hairline crack on the bottom of one of the modules. I haven't really dug into it yet. The second thing noticed was....hooollllllllyyyyyyy mackeral.....it's a NEW RECORD for me!!! This battery had modules date coded 2003 (2), 2004 (1), 2005 (5), 2006 (9), 2007 (7) and 2008 (4). Awesome. Six different years. After sitting untouched from the time it was removed (Friday morning) until Monday night, I took module voltage readings to document initial values. Then I connected all the modules to the CQ3 chargers and did an initial discharge.The data starts with Block 1 (Module 1 and 2) and will be the block voltage and the mAh result of the initial discharge to 6.0 volts. This essentially shows how much energy each module had stored inside of it at the time of battery removal. Notice module 9 was 7.62v and 4257 mAh, yet module 15 was 7.63v and only 296 mAh. Then note how many modules are actually >7.62 volts but had significantly lower energy stored. What a crazy, wild variation. I would imagine modules 15, 19 and 22 were causing a bit of red triangle havoc. 7.79v ---- 2950 7.68v ---- 1037 7.83v ---- 4717 7.72v ---- 1451 7.70v ---- 3011 7.79v ---- 4446 7.78v ---- 2049 7.79v ---- 3437 7.62v ---- 4257 7.73v ---- 2143 7.66v ---- 2293 7.75v ---- 1697 7.77v ---- 2590 7.71v ---- 1902 7.63v ---- 0296 7.67v ---- 2401 7.77v ---- 2732 7.80v ---- 4576 7.48v ---- 0305 7.77v ---- 3971 7.66v ---- 2672 7.51v ---- 0650 7.72v ---- 1111 7.67v ---- 2027 7.69v ---- 3510 7.58v ---- 3135 7.70v ---- 2256 7.86v ---- 4439 Hopefully the columns don't get out of whack when this posts. If they do, it's going to look crazy.......... I wish I had the time to install this battery in my car for load testing prior to the discharge. I bet it wouldn't have lasted 15 seconds before the engine kicked on or it coded out.
19 months of service, I'm amazed. Just shows you can mix in any crap combination of modules and with a little luck, you can get a year+ from a....dare I say "rebuilt" battery.
Insane!!! thank you for taking the time to post and shed some light on the situation. How are the old 2003,2004 modules capacity? Hard to believe the 2003 module is almost FIFTEENTH years old. Amazing this rebuilt battery even worked.. Holy smokes
WOW, I don't think I could come up with a combo that bad even if I tried........I bet there was nothing but standing voltage readings used to rebuild that pack.
Here are the date codes and the initial mAh discharged, same order as post 1. 3/11/2008..........2950 5/10/07..............1037 7/4/08................4717 5/10/07..............1451 5/17/05..............3011 7/4/08................4446 1/23/07..............2049 9/15/06..............3437 12/18/04............4257 9/15/06..............2143 5/17/05..............2293 9/15/06..............1697 2/3/07................2590 7/3/07................1902 5/28/07................296 10/4/06...............2401 9/15/06...............2703 7/19/08...............4576 5/10/07.................305 9/15/06...............3971 9/4/03.................2672 9/15/06.................650 9/15/06...............1111 9/4/03.................2027 4/18/05...............3510 6/28/05...............3135 3/13/05...............2256 9/15/06...............4439
I ran into a battery put together like this recently, with 4 different year model modules in it. The customer had just recently bought this 07 Prius because it had a fresh "rebuilt" battery. After less than a week of driving, he got the red triangle and P0A80. He took it back to the car lot for a warranty on the battery. The dealer's "battery guy" told him it would be $600 to go into it and change another cell or 2. What a warranty! After I replaced his battery and changed his transmission fluid, he sent me this photo the next day, along with a big thank you. He did fill up with non-ethanol and had a nice breeze behind him, but wow!
Very interesting results! Can't believe that pack made it 18 months. The really low modules are ones from 06 and 07 I notice. The 03 to 05 modules look okay. Perhaps the 03 to 05 modules developed higher resistance and therefore were getting more charge? Any chance we could get you to do a 3x charge/discharge cycle on all of the modules and post the results after each discharge? I wonder if some of the "bad" modules were just at a very low state of charge from an imbalanced total battery pack, but are actually in okay shape.
The first two digits are the day of the month. The third digit is the month. X,Y,and Z are used for Oct, Nov, and Dec. The fourth digit is the year. A is used for 1999. Follow the alphabet from there.
