Gen II Prius Individual Battery Module Replacement

You can charge at 5 amps if you run the battery cooling fan while you are charging, and do not charge 2 modules next to each other. If you cannot run the cooling fan charge at 3amps or less.

John

 

Why is hitec x4 stoping at 349 mah when discharging when its still at 7.51v

I have it set up at
.7 amp discharge to 6v

 

Probably you have set on safety timer in settings?
the link below it's manual for your charger.
http://hitecrcd.com/files/X4-80Manual.pdf

according to your previous messages probably you did not read all this thread, you can find a lot of useful information here, and answers to all your questions

Alex.

 

X2

Leave delta peak at default, turn off the safety timer, set waste time to 5 mins, set capacity cutoff to 7000 mAh, 1A discharge to 6V and charge rate no higher than 2A then set cycles to 3 and run it.......let us know what you got.

 

Aloha to all here,

This is my first post. If I inadvertently do not follow Forum / Thread Protocol, please be patient with me.

I am very thankful that this thread exists. Thank you very much ryousideways for your writeup of your experience. Thank you John, Brit Prius for your insightful responses and thank you JDENENBURG for sharing your wealth of knowledge and experience.


I am currently working on reviving our 2005 Prius.
This vehicle is a family essential.

Car Details:

2005 Prius US Gen 2, 176k mi.
Car has been in service to our family in Hawaii since new, (my Wife's dad bought it originally) and it has never spent a day out of the the sun. Maui where we have lived since 2009 has lots of steep hills, and plenty of hot days as well. This car has never given any issues aside from needing a 12V battery in 2010. I did suspect the HV battery capacity was in decline for the past 6 months or more, but have been too busy with college and kids to look into it further, & I was driving a gen 1 Insight, so out of sight out of mind.

When the Orange triangle first showed up I took the car to a friend with a Snap on Mobius scan tool. We checked the Delta SOC, and came up with 50% !!! Total pack voltage was 196V, I do not have the codes that we read, but there were 2 battery codes present.

We determined that the car definitely had battery issues, and I limped it home where it has sat for 2 months while I finished up my classes.

My Details/ Qualifications to undertake this project.
I have been studying electronics for the past 3 years, and I have just completed my Associates Degree in Electronics and Computer Engineering Technology at the University of Hawaii Maui College. I have grown up working on equipment and automobiles of every era from the 1950's to present. I work predominantly on Toyota and Lexus vehicles, however I have recently replaced the HV battery pack and installed a grid charger on a generation 1 Honda Insight.

Currently the HV Battery is out of the Prius and in the workshop. Safety protocols and Class 0 Electrical safety gloves were used during initial removal and teardown of Pack. To anyone who might be considering working on their HV battery, I assume you know this thing is potentially lethal. If you are uncertain of your capabilities do not attempt to work on the HV Battery. If you are going to work on your battery trust your feelings and TAKE FULL PERSONAL RESPONSIBILITY FOR YOUR OWN SAFETY.

When I was removing the 12V battery I found 4" of standing water in the 12V battery well and 2 " of standing water in the left cargo well also. I suspect the tail light gaskets. The presence of water and increased humidity within the vehicle when closed up was undoubtedly contributing to corrosion and possibly causing shorting if/when water sloshed around the 12V battery on little windy bumpy roads. I am going to do a water leak test while the interior and batteries are out (something to do while the battery modules are undergoing cell balancing cycles for 36hrs at a time). During disassembly I noticed considerable corrosion on the connecting tabs of the modules. Also there is damage to the Battery Control Module Orange modular connector where the battery harness connects. Both the BCM and harness connector are damaged with one connecting pin vaporized, and melted plastic/black residue everywhere between the male and female parts of the connector. (photos to follow). I have ordered a used BCM, and am looking for a decent used harness as well.

I have setup 2 Hitec X4-80 quad chargers as follows.

5A charge, 7250mAh charging limit.
0.7A discharge to 6.0V
Safety timer set to 600 min. (I thought 6.5Ahr/.7A = 9.3hr = 557 min. Guess this could have been set higher or turned off).
Discharge>Charge 3 cycles.
Rest time between cycles 10 min.
The modules are all still in the case so I do not have to clamp them while charging.
I am only charging every other module at a time, & I have a box fan blowing on the side of pack to help prevent overheating.


Initial Module Voltages were as follows: (Numbering starts at BCM end of pack).

1. 6.32V
2. 7.38V
3. 7.39V
4. 7.39V
5. 6.27V
6. 6.77V
7. 6.08V
8. 7.31V
9. 7.34V
10. 7.31V
11. 7.32V
12. 7.39
13. 6.04V
14. 7.37V
15. 7.03V
16. 7.36V
17. 7.31V
18. 6.05V
19. 7.31V
20. 6.20V
21. 7.32V
22. 6.14V
23. 7.36V
24. 6.14V
25. 7.06V
26. 7.31V
27. 7.21V
28. 0.19V

Now obviously Module 28 is in very bad shape....
I am concerned about Modules. 1, 5, 7,13,18,20,22, & 24. Module 6 was under 7 volts, but not as low as the others.

The data from the first modules charged is in. All values are in mAh

Batt. DSCH1/CHG1, DSCH2/CHG2, DSCH3/CHG3
1 ____ 2593 / 5987 , 3936 / 5859 , 3867 / 5863
3 ____ 3247 / 6598 , 4509 / 6960 , 4787 / 7093
12 ___ 3179 / 7019 , 4642 / 7230 , 4752 / 7126
14 ___ 4386 / 7047 , 4609 / 7108 , 4732 / 6429
16 ___ 4404 / 6854 , 4426 / 6847 , 4487 / 6721
18 ___ 1420 / 3118 , 1295 / 3166 , 1280 / 3164
25 ___ 3609 / 7213 , 4907 / 7250 , 4930 / 7227

Only module 25 seems to have taken the full 7250mAh of charge. Modules 3 & 12 &14 came close to taking the full charge capacity limit of 7250 mAh... The discharge phases discharged less than 5000mAh in any given module. 18 clearly is the most degraded.

I do not think this looks good so far, but I could live with a functional balanced pack that has a lower than original capacity for a year or two then revisit the issue as needed.

Right now we need to get this car back up and running as soon as possible. Getting anything in Hawaii is rather difficult, slow, and more expensive. As a result we tend to do a lot of things that are not cost/time effective to attempt to DIY elsewhere in the world.

I am hoping to get some feedback or thoughts from members of the Prius Chat community as to my progress, and what level of reconditioning is possible given the condition of my modules thus far....

I will update the data as it comes in after each charging cycle completes.

Although this is my first post, I have been here often and have always appreciated the information I have found so readily when it was needed.

Aloha from Maui

 

I received my two Hitec 4x chargers in the mail yesterday only to find out each only has 1 pair of alligator clip connectors and everywhere seems to be sold out of extras. Does anyone have any leads to some for sale, or suggestions (I need 6 more pairs)?

 

@ iduncan, maybe consider lowering the input current to ~350mA and charging for longer.

Also, have you seen the thread on rehydrating modules: Re-hydrating The Battery Modules | PRIUSchat. Given your background and circumstances, maybe your modules could benefit from this too.

Lastly, do not rush this process, like making cheese, this stuff just takes time.

 

As member "dolj" says above there is no quick fix, and although as the initial author of the post you could say I am biased. I really believe re-hydrating the modules in your battery would not only bring back lost capacity, but also greatly reduce the risk of having to return to the process in the near future.
The extra time taken is minimal particularly as re-hydrating modules can be carried out while others are on there charge cycles. The method is simple and easy to carry out. Extra cost is also minimal, and improvements "may" even be shown by just adding distilled water. Not having tried the water only approach I cannot vouch directly for it, but other peoples result do seem positive so I will not discount them.
The modules seem to loose capacity mostly by drying out over time, and this can then lead to further problems like reverse charging of cells or overheating and melting the separators.

John

 

My Hitec chargers came with only 1 pair of alligator clips each as well. They also had 3 other pairs of 4mm bullet connector terminated wires to plug into the chargers with various connectors on the far end. In the interest of getting things moving I ran to the hardware store and found ring terminals and some closely matching 18AWG black and red wire. I cut the unneeded connectors off, and soldered up appropriate length leads with ring terminals that slip over the + and - studs. I tightened down OEM connecting tab nuts on each terminal, and we are in business. Alligator clips are nice, but not necessary. Good luck.

 

@Britprius & @dolj :Thank you for the suggestions. I will read the thread on rehydrating the modules straight away. After a decade plus of operation in a harsh environment I am sure my modules have all lost some amount of electrolyte. I will likely seek out the electrolyte chemicals and mix at a middle of the range concentration as opposed to adding just water, although I will read further about this before deciding which way to go.

I had a feeling I needed to open the battery case and address corrosion, test voltages etc. a while back. Of course when the car was running and needed every day there was little opportunity to address my suspicions.

I love this quote.

I will slow down and make sure it is done the best that I can. I still want to collect all the data from the current charging protocol, so I am inclined to follow it through for the remaining modules. I will decrease the charging current to 350mA for subsequent charging cycles and see how it goes from there...

It looks looks like I will need to make extensions for my charging leads so that I can move the chargers off of the top of the pack and have room for the re-hydrating process while still charging the other modules.

Thank you both again.
Aloha

 

Ideally the modules should be removed to hydrate them. This way only 2 holes need to be drilled in each of the 28 modules making 56 holes to seal. It can be done with the battery in place, but this requires holes drilling above every cell meaning 168 holes to be sealed.
Otherwise there is no difference. Any questions just ask in the re-hydrating post and I will be happy to answer.

John

 

Thank you, I was just reading about the hole layout and reasoning in the re-hydrating post. The drill plan makes perfect sense. The current charging cycle will finish out by tomorrow. Then I will remove the modules from the pack and begin rehydrating. In the meantime I will find the necessary hardware and Potassium Hydroxide. I will also order a used battery module or 3 to replace failed module #28, and a have spares.

Things are looking up.

 

Thank you very much, i had put 30 min on safety timer instead of turning it off. Problem
Solved

 

That was funny ! . You made my day , dude !

 

Drill one hole in each module before removing them. This will release any pressure in them from the cycle charging, and prevent possible bloating of some modules.

John

 

Good thinking. I will drill one hole each before I remove the modules from the pack to release any pressure. I am thinking of "purging" the pressure release valves to make sure they are not stuck. Would it be a good time to do this when each module has one hole in it & the pack is still compressed by the tension bolts?

Thanks,
Ian

 

Yes that is the ideal time. once that is done there is no further need to compress the modules even when charging until the holes are sealed again. I found a cheap 12 volt compressor perfect for this job as once the valve releases the output from the compressor being low in cu ft min terms just keeps the valve leaking at it's normal opening pressure.
If you cannot get hold of the type of football inflater I used an ordinary rubber tyre valve "the type fitted in steel rims" fitted onto the pump outlet , and held firmly over the drilled hole works well.

John

 

Im rebalancing my hv battery module and also decided to take off the copper plates to get them clean so i left them in the kitchen for the night and when i wake up my mother threw them to the trash. Does anyone know where can i buy these copper plates that pair up the modules?

 

Where can i find these copper plates?

 

You are in TX. There are few battery shops in Texas, e.g. Huston. Normally any shop specialising in battery rebuild would have piles of those.
They are surplus to requirements. You'll easily find them. Shouldn't cost you more than few bucks as the only value is cost of bare copper.