Gen II Prius Individual Battery Module Replacement

Dont get rid of those bad modules, if voltage and load is ok, someone could use them to match a pack. Albeit degraded, they're still worth 30 a piece on ebay. Or you could offer them up to someone here for experimentation.

 

X2

I was surprised how well your degraded modules have been doing so it's worthwhile to offer them up to others with known specs.

........when folks do this just be sure to test them for both capacity and (especially) load.

 

Heres what my 53mpg gen 1 looks like, after much effort...

 

She's a beauty.

 

Thanks sarge

 

You got to love the first generation I never see any in the mountains .

 

I have three sitting in my shop's parking lot right now. They look so happy grouped together! Each had different issues, but now they are all purring along nicely.

 

Here's updated results .

 

How much do you sell them for Eric?

 

Generally I'm not in the business of selling cars.
I mainly in the business of working on other people's hybrids.
The one's in the lot today had an oil overfill and throttle body isse, a bad battery pack, and a fuel delivery issue.

But in this case, I happen to have one of them for sale. See my other thread here.
Selling my 2002 Prius. 201,000 miles. $2,100 | PriusChat

 

What does this mean ?
Discharge 3687 Charge 7502
Discharge 4892 Charge 7500
Discharge 5274 Charge 418
Looks like it was improving nicely then the last charge was bad .

 

could have been a delta peak fluke. I would charge it again but set the cutoff at 7000mah

 

I charged it again and it went from discharge 381 to charge 7501 I hope I`m not charging them to high a little late now if I was .

 

Its probably fine. The numbers looked good before that one cycle. Remember to discharge them all a bit prior to equalization. I set my chargers to discharge to 7.6volts. This way, your somewhere in the 40 to 80% soc. Then do your equalization.

 

You're fine, it was probably just a blip in the AC power or charger misread the delta peak.

Also heed danahurling's advice on bringing down the SOC before balancing (you want them all around 50-60% SOC before balancing begins)

 

I`m doing a resistance check how long would I expect the module to last at a 5 amp discharge ?
Also what is 50-60% SOC in terms of Voltage would that be around 7 volts charged to 6500mah .

 

I load tested with a halogen headlamp and a timer and switch. Its on another thread here. As far as the discharge, when I set my chargers to 7.6 volts on discharge, they all dropped by about 800 to 1000mah. This is all you need. You just cant install a pack that is at fully charged because the computer will throw a code if the voltage it too high. The computer itself runs the battery at a 40 to 80% charge. So at 100% charge, the computer will think something is wrong. My modules were of course at a different capacity than yours. If you set your charger to discharge to 7.6volts, see how many mah It takes off, I would guess you'd be taking off 1500+, at 5000mah soc, your within the acceptable operating range for the computer to recognize the battery as healthy and operational. Just my 2 cents. Others may have different methods. Just do the math, your charging to 7500mah, but your balancing so in actuality your mods are at 6500mah, as long as you discharge to 5200mah or less, you'll be fine. Discharging to 7.6 volts worked fine for me. If that doesnt pull enough charge out, go to 7.5 or 7.4. I dont see a need to go down to 7v.

 

Okay I`m getting close Whats the best way to clean the bus bars mine have some corrosion on them .

 

I disassembled mine into the individual pieces. They snap out of the orange plastic. You end up with a bunch of 2 inch copper plates. I threw them in a bowl of vinegar, though this may not have done much. I sandpapered each bar until they looked like a new penney. Some of them were pitted with corrosion, so these ones didn't turn out, but the pitting was too deep to justify thinning the material. Just get them as clean as you can, aim for new penney look, but don't grind away much of the thickness. A little pitting is ok, just get the corrosion off. Wear gloves. This stuff is nasty. Use a 400 grit paper, you dont want an aggressive paper so they stay thick... I can imagine if you thin them to much, they could get hot, warp, and create problems down the road imo

 

For a few hundred bucks you can buy new ones. This will save you the frustration and unreliability of any broken/failing sensors.