Gen II Prius Individual Battery Module Replacement

Matt, you're right, I meant to say sealed (both AGM and SLA) batteries are required when inside the cabin.

 

Was starting to think you guys on the other side of the map got AGMs .. was feeling a little ripped off lol

I actually got super lucky a bit over 12 months ago found an optima d51-t1 in the drop off pile at the local junk yard! took it home buffed it up cycled it a couple times and to this day its still in my car

 

I'm running into some anomalous results, so I'm just going to throw them out there and see what you think is going on.

Traction battery is out of a 2004 Prius, so Gen II. When the battery was out of the car, the SOC was all over the board. So I decided to run a charge discharge on each module.

Charger: Reaktor QuadKore 4x300w 20A with a Turnigy 1080w power supply.

First round settings
Charge at 5A Discharge 3A
Set DeltaV at 3mV/cell
Charged down to 6.3v

#1 5457-8357 // 6586-8288 // 6671-8292
#2 5974-8500 // 6752-8698 // 6848-8709
#3 2258-8357 // 6214-8187 // 6394-8192
#4 6021-8407 // 6538-8182 // 6610-8238
#5 2189-8355 // 6222-8165 // 6429-8217
#6 5616-8158 // 6494-8290 // 6592-8497
#7 2196-8508 // 6354-8228 // 6537-8185
#8 6621-8431 // 6711-8643 // 6597-8297
#9 2142-8445 // 6337-8200 // 6461-8160
#10 2091-8553 // 6373-8264 // 6597-8297
#11 2119-8453 // 6363-8287 // 6514-8218
#12 0819-8058 // 6551-8364 // 6726-8598
#13 5355-8678 // 6650-8779 // 6811-8811
#14 2248-8217 // 6112-8161 // 6343-8176
#15 2189-8684 // 6529-8348 // 6537-8266
#16 2175-8397 // 6305-8063 // 6281-7950
#17 6332-8369 // 6618-8320 // 6681-8435
#18 2197-8438 // 6392-8165 // 6522-8230
#19 2178-8562 // 6387-8284 // 6436-8141
#20 2291-8314 // 6280-8385 // 6549-8248
#21 2119-8547 // 1878-3239 // 6368-8127
#22 2048-8112 // 6157-8096 // 6473-8089
#23 2154-8906 // 6603-8399 // 6609-8275
#24 6192-8262 // 6477-8220 // 6574-8350
#25 2284-8489 // 6307-8411 // 6534-8361
#26 5112-8703 // 6590-8490 // 6610-8531
#27 6301-8614 // 6864-8738 // 6953-8997
#28 5383-8190 // 6546-8378 // 6660-8238

All of the modules where at around 2xxx on first discharge. The reason some of the initial discharges in the above data occured is because initially I used a 7300 safety stop, but on each attempt the safety cutoff was hit. So, I raised the safeties and let the DeltaV do it's job. I did keep on the temp safety stop at 50c, which never were triggered.

Initial load test shows 7.99v-8.2 but I haven't harnessed the unit to balance them out yet.

So, what am I looking at, a miscalibrated charge computer? I'm at a loss. Those numbers can't be right.

 

Hi Qvox,

I'm not sure exactly what you are asking. For the most part that battery looks pretty good. Had it failed before you pulled it out the car?

What do you mean? How did you determine the SOC was " all over the board"?

You should use a 12 volt battery as the power supply. Then you could do a regenerative discharge at 20 Amps.

Low power discharges, typically 1 amp, but even a 3 amp rate can allow a weak cell to hide behind five strong cells. The Reaktor is capable of regenerative discharges up to 20 amps.

I think you mean discharged down to 6.3V.

What are you using for the load test? How are you doing it? What does " harnessed the unit to balance them out yet" mean?

The numbers you posted are consistent with low power discharges performed with minimal wait time after charging. What makes you think they are not correct?

Brad

 

This is not balancing the battery. What you're talking about is called voltage equalisation, and it doesn't really achieve anything worthwhile, so is a waste of time and effort.

 

Thanks for taking the time to answer my questions. I'm very much still learning, so ALL advice is much appreciated. My final voltages are ranging from 7.9v-8.2v Do I need to bring all these down to within .2v of one another?

I'm ready for this to be over....

 

Thanks for taking the time to respond.

So how would you do it? I thought it was important to have all the modules at the same voltage.

 

More important is to have all modules with similar characteristics of capacity, internal resistance and the rate at which they charge/discharge. Get them to the same voltage with your charger.

 

Isn't .2v ? What about acceptable capacity ranges?

 

why cant i reply??

for some reason my post never posted.

so here goes ...

my 06 has 294,000 miles on it and i did the alot of research about the red triangle and gsc code, i took the hybrid battery out and tested all the cells .. one is 6.9 two are 7.9 and the rest are 8.2 at the time of testing ... im going to buy a charger from a hobby store a(( i cant post the link or picture )) so i can charge the cell once it gets here .. i have seen posts of people charging 6 cells at a time .. why if lets say they only order 2 cells to replace?? for mine as of right now i only need to replace the one at 6.9 ... correct??

 

The static (or resting) voltage is not so important, and I believe the voltage diff is 0.3 V. But this is measured when under load charging/discharging.

 

People are attempting to recondition their NiMH modules. Over time

I would run a discharge-charge cycle (3x) on all 28 modules. Then test them all with a load. More than likely the the one that is 6.9v has a bad cell. But to be sure while you have it out it's a good idea to do all the modules and then test again. Then order the modules you need.

I'm sure there are others that have more experience than me, but I just finished rebuilding my traction battery, installed it today, and went for a 20 mile test run ....so far so good.

Thanks to all the contributors in this thread, everything came out great. My total cost was around $50, but I already had the charger.

One thing I wish this forum had was one definitive, step-by-step procedure, this thread is great, but you really have to weed through a lot, and piece it together.

 

hi .. your 6.9 will be a poo! I wouldn't trust the 7.9's either they will be the next two "wack-a-mole" specially if they are in positions 1&28 .. be a good idea to just swap out all three with good spares if you can

 

I agree with that....replace the 3 and button it up get on the road. Order 1 or 2 spare module and cross fingers

 

I've compiled brief Animated GIF from 4 tests on two failed 2010 packs. Those are NP2 modules which can be found in both 2010 Prius Z30 (battery could be made in 2009) as well as in 2009 Prius NHW-20.
42% of those 56 modules are waste. And none of those were showing below 7.2V in the idle mode.
24 still usable modules from those two packs together with another 4 modules with similar behavior under load formed part of the "rebuild pack" with URC > 2AH.
GIF is on the front page of my site, too big to post here.
http://www.hybrids.nz

 

Is there any way to pause or slow down the gif?
It goes by a little to fast for me.

 

Eric, GIF size increase with number of frames. 4 screenshots lasts 1.5 seconds each and the last one is 2.5 sec. Resolution is 800x600 with 10 fps. Even then file size is almost 17 MB. Everything is doable of course.....
I could've made "longer" GIF and post here, but Priuschat has restrictions for the GIF size. Making it smaller to fit into 10MB would require resizing and you won't be able to see graph details.

 

Good info thanks.

See, for me, I tend to internalize difficulties. I just assumed it was possible to pause it and I simply wasn't smart enough to know how to do it.

But it turns out that it is actually way more complicated than I imagined.

Good info. Thanks.

 

Eric, you can just screenshot (the paste to MS paint or picture manager) the GIF at various times if you want to look at something more closely.

 

Yep. That's what I ended up doing.
Thanks.