Gen II Prius Individual Battery Module Replacement

What should resistance be for module series?

I mean, what is too high and what is normal for an older battery and also what would it be if the battery were brand new?

I was looking at Techstream and noticed block #3 with a resistance of .031.

Also, which side would that block be if I were looking inside the battery, the ECU side?

 

Question...I remember reading somewhere about it but cannot find it. Cant we just change a block at a time ? leave one of the bus bars connected and do 2 modules at once ? the hitec x4 shows it can do 15 cells at 1.2 volts so it should be fine. any ideas on this ? also ev-peak model CQ3 shows it can do up to 5 amp discharge. wouldn't this reduce the cycle time for this?

Thank you.

 

Yes you can charge a block at a time but this has a number of problems.
You cannot get individual module capacity information, and the better of the two modules will only be charged to the level of the weaker module defeating the purpose of the charge discharge cycles. It will also mean charging modules next to each other creating more localized heating.

John.

 

I've set my two chargers up to these settings:

5 amp Charge
.7 amp Discharge to 6V
7250 mAhr
dsc<chg 3 cycles
5 minute cool down and 720 minute safety.

The modules are still in the battery pack in my living room with a box fan blowing on them and I'm skipping at least one module in between the ones I'm charging.
Anyone see anything wrong with this set up?

 

Fixed it for you......

 

So a 5 amp charge is too high?
I've already charged some at 5 amps.

These are some numbers from one of my modules:

C-0142; 0128; 0119
D-0202; 0169; 0151
Would I be correct in believing this module is bad?

 

Cycle charge/discharge does not imporve anything. Wasting your time.
If you after quick evaluation of which ones are dead or too weak - use 4-8 Amp light bulb and chronometer to evaluate remainign capacity down to say 7V from fully charged - the whole process will take you much less time.

 

The best internal resistance I have seen Techstream read is .018. Good is .019 to .023. A reading of .031 is very bad. The worse I have heard of. The Toyota repair manual and most Prius Chat members will tell you that for a Gen II Prius the module count starts on the ECU side. I disagree based on dozens of personal observations the module count for a Gen II Prius starts opposite the ECU.

Brad

 

The confusion by some is what is GEN I vs GEN II etc.
Readers here are not only from USA
In Japan, Russia, New Zealand, Australia and UK (in the order of quantity) and some other places there are NHW-10 - first ever Prius.
To avoid that confusion I suggest people use chassis as a reference:
NHW-10 (JDM 1997-2000) Count from ECU
NHW-11 (aka GEN-I in USA only) (2001-2003) Count from ECU
NHW-20 (aka GEN-II in USA only) (2004 - 2009/2010JDM) Count towards ECU from another end.

As a reminder to Techstream fans - it has limitations, i..e. what you see is not the true reflection.
I have published example where Auto Tech (I know the guy, he is pro in what he does) used Techstream and Voltmeter to identify only ONE bad module.
28 Channel Battery Analyser in action – Prius 2009 - HYBRIDS
I run full load test on that pack and found 2 failed and 2 near fail modules and the rest - very low remaining capacity and not in conformance with each other - which would mean the "Usable Remaining Capacity" would be very low even if there were 4 modules changed.

That pack by the way is still with me to test my newly built Analysers and new type of loads and chargers (not published on my site yet). That pack is a perfect example to provide bullet-proof argument supported by multiple documented tests that "cycle charge/discharge" did not improve that pack performance, nor did it raise tired old modules capacity (in that case 5 years, about 160K miles or 256000 kms).
Previous old packs I've used to test HV Loads and HV Chargers have already died.

P.S. Internal resistance as displayed by TS is the least of your worries.

 

Thanks... so just one bad module in a block can cause the high resistance then? What should I do, replace both modules?

 

one is likely to be bad and the two adjacent ones (one of which is paired) are suspect due to extra heating from the elevated resistance.

JeffD

 

Actually, looks like all my resistances are higher than 0.23.

When I first start the car up, I get resistances between 0.25 and 0.27 with one block at 0.29.

So, I assume my whole pack isn't that great.

 

That is a symptom of living in a hot climate. Heat is the enemy!

JeffD

 

Here are the results of my charging:

1) C D
7251 5966
7250 6021

2) C D
7250 2321
7250 5543
7250 5659

3) C D
7251 6073
7250 6028

4) C D
7250 2032
7250 5516
7250 5879

5) C D
6677 2290
7189 4536
7250 5213

6) C D
7213 2377
7250 4724
7250 5397

7) C D
6929 2821
7140 4692
7250 5335

8) C D
6947 2938
7250 4998
7250 5392

9) C D
0142 0202
0128 0169
0119 0151

10) C D
7250 2743
7250 4897
7250 5352

11) C D
7250 0993
7250 5766
7250 5841

12) C D
5812 1541
6258 3811
6754 4480
7250 4241
7250 5269
7250 5549

13) C D
7251 5372
7250 5471

14) C D
7250 2145
7250 4948
7250 5481

15) C D
7250 5623
7250 5725

16 ) C D
7250 1699
7250 5091
7250 5568

17) C D
7251 5718
7250 5817

18) C D
5354 1411
6405 3940
6845 4556

19) C D
7250 5828
7250 5849

20) C D
0183 3087
7250 0218
0184 5284
0108 0262
7250 0126
0116 5851

21) C D
0284 2951
7250 0321
0212 5184
0105 0325
7250 0125
0111 5721

22) C D
7050 2149
7250 4585
7250 5092

23) C D
0115 3904
6981 0158
7250 5148

24) C D
0198 2010
7250 0228
0169 5342
7250 0325
7250 5836
7250 5885

25) C D
7250 3214
7250 5137
7250 5466

26) C D
7250 5638
7250 5756

27) C D
7250 2310
7250 5330
7250 5679

28) C D
7251 5787
7251 5788

1, 3, 13, 15, 17, 19, 26, and 28 were the first group I cycled and they all had an initial cycle that was not recorded. I am currently putting 9, and 18 through another cycle so it looks like 20 and 21 need replacing and possibly 9. Any agreement disagreement etc.?

 

Module 9 does appear to be faulty, but 20 & 21 show final discharge figures that are good at 5851 & 5721. The input figures on these cannot be correct at around 0100. You cannot take out more than you put in. (I wish we could)
Module 9 was only charged with about 0100 mah so it's output is also going to be lower than this. Why was it stopped from charging at 0100 mah. This should be rechecked.

John

Looking at those figures again I can see why modules 20 & 21 strange readings. I will just describe module 20 as 21 has the same characteristics.
At stage two module 20 was charged to 7250, but only discharged to 0218 leaving a large quantity of charge (about 5100) still in it.
It was then charged again accepting 0108. This is added to the 5100 still in the module giving the next discharge 5284 discharging it almost fully.
The next charge was only 0108 added to the small amount left in again gave discharge of 0262.
The next charge was 7250, but only 0126 was taken out again leaving a substantial charge in the module.
The next charge of 0116 added to what was left in the module gave a final figure of 5851 mah.

Module 21 follows the same pattern.

The discharge is being stopped early for some reason upsetting the figures.

John

 

My settings were
D>C
D .7A 6.0V
C 3.0A
5 minute waste
7250 cut-off

I checked my settings for #9 before I started the ongoing cycle hopefully it will cooperate this time. I have checked my settings each time for #20 and #21 is there anything I might be doing or anything else I should check on these two? I will be giving all modules a 24 hour period to discharge before checking voltage and putting them in the harness.

Sorry you answered some of my questions as I typed.

 

Looking at module 9 it ever received a charge of around 0130 so again it cannot give out more than was put in. Since the module a somewhat less than 100% efficient the out put would always be less than the input.
So I suggest you charge this one again. It could be that it is faulty, but give it a fair chance.
What delta peak voltage is set in the charger.

John

 

I left them all at default. I will look through the manual and see if I can find what default is listed at.

The default delta peak setting is 7mV.

 

Is it possible to turn off the peak setting or turn it to zero or a higher setting.
This setting stops the charging process when it see,s a cell voltage rise then fall a few mV. Something NiMH cells do at full charge. It can however be to sensitive and shut down the charging early. Poor connections from the charger leads can cause this.
When discharging again poor connections from the charger discharging the module under load will cause a voltage drop. If the voltage seen by the charger falls bellow the set limit (6 volts) discharging will stop.

John

 

It does not appear to be an option to shut it off or set at zero, but you can set it anywhere between 5mV and 20mV. What would you suggest?