Traction battery rebuild question

Hello all,

I'm rebuilding my traction battery, 2006 Prius, using info found here. I have a question as the numbers are coming in, but first:

Bought 4 DC-6 chargers ($120 shipped HobbyPartz), 1 replacement cell off eBay ($44) to replace one with about 1.5v less than the others, and linemans gloves (eBay, $20 shipped).

3-chg/dschg cycles, .7 amp discharge to 6v, 5 amp charge to 7500 mah, 5 min rest between cycles, 720 min timer.

Here are the results for the first 4:

CELL#1
DCHG #1 3689
CHG #1 7501
DCHG #2 5316
CHG #2 7500
DCHG #3 5698
CHG #3 7500

CELL#3
DCHG #1 3792
CHG #1 7500
DCHG #2 5482
CHG #2 7500
DCHG #3 5724
CHG #3 7501

CELL#15
DCHG #1 3025
CHG #1 7501
DCHG #2 5077
CHG #2 7500
DCHG #3 5595
CHG #3 7501

CELL#17
DCHG #1 3874
CHG #1 7500
DCHG #2 5246
CHG #2 7500
DCHG #3 5709
CHG #3 7500

[COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414]Comparing these figures to others posted on here, I'm concerned I've set something up wrong. Every charge cycle is showing the same 7500 mah as opposed to numbers all over the place.[/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR]

[COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414]Please comment. Did I set it up wrong?[/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR]

[COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414][COLOR=#003399][COLOR=#141414]Richard[/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR][/COLOR]

 

As you can see from the pic, I removed the top 2 support rods. As soon as the next 4 modules are done I will reattach it. I was confused about the bus bars and thought that's what everyone meant to remove, I now know they meant the orange and copper strips that connect the modules.

I wish I could stop this cycle and do it now, but I'm 20 hrs in and don't want to mess it up.

 

Wait, I'm unplugging the chargers and starting over. I think the modules not being tight in the case is the problem.

 

Ok I think I figured it out. My guess now is the -dV/dt peak is not being reached because the modules are not compacted enough and the chargers are just stopping at the programed 7500 mah cutoff. I will start all over and post new results in a couple of days.

 

Jeff,

This appears to be the problem. I may have ruined a couple of modules, I'll have to wait a few hrs to see if the swelling goes down.

Everyone said to remove the bus bars without explaining exactly what the bus bars are. From watching the videos I knew to disconnect the copper strips to prevent a shock, but didn't know they were called bus bars. So I removed the top connecting rods as they appeared to me to be "bus bars", and the modules were not as tight as they should have been, as they were connected only by the bottom 2 rods.

I think we're getting close to the point where someone can write up a complete DIY guide from beginning to end. We should all post here when we do this rebuild and eventually we'll get it right if we share info/experiences. Hopefully we won't lose anybody.

Too Wise

 

Jeff,

Will it be allright to redo the first 4? Or should they be ok and just go on to the next?
What about the 2nd group of 4 that I stopped on the 3rd discharge cycle? Just start over?

Too Wise (whispered in a soft, sarcastic tone)

 

Ok, it looks like some modules have been ruined. Some have swelled slightly, just enough to prevent me from getting the case back together. I will disassemble and inspect the modules. If I have to replace more than 2-3 of them, I may abort the rebuilding process and source a salvaged battery.

It's a shame, because I thought I had this figured out, but no real harm was done as I was going to get a used battery from the beginning. At least now I'll have some spare modules for next time.

I need to change my handle.

Two Y's for you

 

More bad news, but I'm not giving up unless I get smacked across the head with 220v DC!

After removing and reinstalling the modules a few times, I've stripped most of the screws that hold each module to the frame. Some screws have twisted right off. Very cheap, soft metal. I've emailed the guy on eBay I bought the module from and begged him for some new screws. Off to Harbour Freight for screw extractors and a tap and die set.

I have to admit a few days ago I was tempted to reconnect the bus bars, take off my shoes in the garage, and grab a hold of #1 and #28. I needed peace, at last, and that seemed my best option at the time. But after a couple of cool-down days, I decided instead to go to Harbour Freight. The good news is the swollen modules appear to have un-swollen. I won't know for sure until I get the screw situation sorted out. Anyone know what size the screws are?

I'm going to look at an '05 Prius tomorrow with a known bad battery, for cheap, because I know I'm on the cusp of glory!

Too Wise

 

Hello all, I've been out of town and just now getting back to this.

I've got plenty of new screws and I'm ready to reassemble the pack and try again with the chargers. Please look at the below pic and tell me how to get the end cap around the bolts sticking up from the bottom of the tray. The bolts appear to be machine pressed in. If they would come out it would be a snap to tighten everything up with the 4 long bolts and then put these 2 back in.

Any help?


Too Wise

 

Also, there are 3 pairs of wires underneath the battery. They connect to #1, 15, and 28. They attach with a plastic clip and appear to be sensors of some type (heat?). I can't get them to connect back to #28. Can I just tape them on?

YY

 

Ok, I got it together. I put the end cap on and left one module out and then slowly worked the module down in there. It took a while, but they're all lined up and tight. I didn't have them tight in the pic, just trying to get an idea of how to do it.

Any comments on the wires underneath will be appreciated. They just appear to be stuck to the bottom of the modules and don't do much.

Tonight I start the balancing/charging process again.

I refuse to let this project kick my nice person, it's gotten personal.

Too Wise

 

Thanks. I can't get the wires to connect. I'll tape them.

New problem. When I was being aggressive with the cells, trying to get them back in the case, I must've cracked the last one. About 8 hrs into the cycle I heard a bubbling sound and saw fluid leaking out of it. So I'll order a new one as soon as I finish the discharge/charge process and can verify all my modules are good and I don't need anymore. So far the numbers are looking good, even the one from eBay.

Getting the case back together is now my stumbling block and I'm going to have to crack it open again. If the pressed-in bolts would come out it would be so simple. I cracked a module by pounding on it. Anyone who is willing to share info on this procedure will be greatly appreciated and loved.

If I can't figure this out this whole exercise will be epic failure.


Two Y's

 

Sideways, outstanding idea!

Hopefully I'll be ok as all the bottom screws are in and the module I cracked is the very first one. Maybe it'll go right in without an issue. That'll be a first for me.

I ordered another module on eBay, this one for $35.

Good luck, Sideways. Hopefully we both can get through this sucessfully!

YY

 

Ok, got the case back together with the new module. No problem as it was the first one. My last 3 modules are happily charging.

Advice please: When discharging to balance voltage, can you set the DC6 to discharge without running a charging cycle? If not, I'll just set a long delay between cycles and try to catch it before it starts charging. Or I guess I could set the charge voltage to be the same as discharge.

I had one interesting module story:


CELL#28
DCHG #1 2867
CHG #1 7501
DCHG #2 3492
CHG #2 1425
DCHG #3 1405
CHG #3 2964

Wth? It started out normal enough, but fell apart on CHG #2. Nothing to lose at this point and I was ready to order a 3rd module off eBay, so why not keep going:

DCHG #4 2901
CHG #4 2292
DCHG #5 2211
CHG #5 1490

At this point I knew the module was shot, but put a different charger on it just to make sure it wasn't the charger and ran another:

DCHG #6 1448
CHG #6 7500

Hmmm, those look like better numbers, so ran 2 more with the new charger:

DCHG #7 5508
CHG #7 7500
DCHG #8 5631
CHG #8 7500

These numbers are fine and match up with the others, so I kept that module in the pack. The weird thing is, the first (bad?) charger charged the next 2 modules just fine. Bad connection? I do not know!


Too Wise