Re-hydrating the battery modules.

Roy,
Cleaned them while bolted down...Checked with DC meter but did not check from positive terminals to case (ground). dried with dry cloth and paper towel before reassembling. I have the battery cover off so I can see the modules. We are in a very humid weather pattern, so air dry is not likely. Is there a way to measure voltage per each module to see where leak may be occuring? your comment above leads me to believe that if I measure from positive terminal to ground with harness off, and get any reading, then that module may likely be the leak? I will let it set overnight and check again tomorrow....May check each module to ground....and, I may have to take the rascal out of the vehicle, disassemble and clean each module. If I have to do that, I might as well rehydrate the rest of the modules even though they have not thrown codes......Could the wire harness be the issue? Is there a possibility that a leak could be occurring somewhere other than the battery?? In case I forget to mention it, I really appreciate your help...You fellas have been a great help to this novice....Thank you sincerely!

 

With the harness off each module can be tested to ground individually - my only concern is there is dampness on all the modules from your cleaning and they all may have ground readings until everything dries out. Modules that have leaked battery chemical on them will be much more conductive (have higher voltage readings) then ones that are just damp.

You could not properly clean the modules in place and in the battery housing, because the modules are bolted down I know It is a difficult job to get them out - if you tried to clean the rest of the batteries with water while in the housing you will get the code from them if there is a film of dirt on them that gets damp.

This may be a long process but removing all the modules - cleaning with soap and water and then clean water and making sure it is all dry before re-assemble plus test each battery module when dry and clean for voltage from the positive terminal to ground on each module before you attach the bus harness - any module that has a voltage above .01 volts to ground should be cleaned and dried again. I had some modules that were as high as 5 volts to ground before cleaning. The drying may have to be done with a heater with a fan indoors to be sure they are dry. If the module is being tested outside the case - put a hold down bolt in the bottom of the module and test from the positive terminal to that bolt (the bolt normally grounds the module to the battery case). If they are in the case and bolted down after cleaning and drying then just use the bare metal of the housing as ground.

The wire harness itself cannot cause a ground normally - its the modules conducting small currents down the sides and front and tops of the module, any dampness on battery is likely to give the code.

Inspect the case where the modules were resting to see if there is any corrosion, if there is clean and paint that area of the housing.

Go back and look at post 216 ( which I have edited ) when I should have said to remove the 4 modules for cleaning and inspection - I should have been more clear about removing the modules so I edited my 207 post in case others try to clean the modules in place.

 

My multi meter has a resistance scale of 200 M ohms. I use this to measure from each terminal to different points of the plastic case. I have seen resistance of 100 M ohm set the code. The small amount of leaking and dirt can be too small to see. As Roy said wash, rinse and sun dry all of the modules. A leaking module can contaminate its neighbors so it is best to clean all off them.

Brad

 

Hi Brad - as you may know most multi meters use a 9 volt battery to measure the resistance - because of the low voltage in series with resistors and the meter movement it does not work as well as a 250 or 500 volt megger which puts 500 volts dc across the positive terminal to ground ( the battery could have up to 325 volts dc to ground), however most people would not have a such a device.

A combination of a low voltage reading and or a high meg ohm reading with an ordinary meter will usually tell if the module is clean and will not conduct to ground. People who are putting the chemical conductor in the filling water are especially prone to have problems. Straight distilled water is less of a problem and as it not as conductive. Straight distilled water is a poor conductor until it gets contaminated with salts or minerals.

When I re-hydrated my 38 batteries in place I used distilled water but did not cap the filling holes right away - thus during testing with the car charging and discharging the modules, some boiled up and spilled corrosive liquid out of the battery causing code p3009. I installed the filling screws,pulled all the modules from the battery and cleaned and dried them, sealed all the filling holes and screws with liquid tape, re-installed the modules and the p3009 went away.

Anyone trying to do a battery in place as I did, should seal all filling holes (after installing the liquid) before running the car.

Roy

 

Roy, You are right as rain.!..
I tested each module with the harness removed. I had 9 modules with voltage to ground of 0.1 or higher. One module was 3.7 That was one that I rehydrated. I pulled battery, removed all the modules and could clearly see the moisture and corrosion on the bottom of the battery housing tray. I took some before and after pictures and may post them for all to see. I cleaned the battery housing, let it dry in the sunshine, and then gave it two coats of paint. I also cleaned each module with hot soapy water and placed them in the sunshine to dry. I want to give everything more time to dry completely, so everything is now in the garage for the night. I will put it back together tomorrow and test each module before I reattach the wiring harness. I would not have believed that there was that much moisture, and corrosion from rehydrating. I believe I erred most when I tried to clean the modules in place after filling with juice. that extra moisture on the exterior of the modules clearly caused the leak. ( I hope) . It does not appear that any of the machine bolts in the filling holes have leaked. I will give an update tomorrow after all is back together again. I did not rehydrate the remaining modules....I decided to wait until I get a code for weak bank. No sense kicking a sleeping battery module. Lesson: keep your powder ( and battery ) DRY!

 

Glad to hear you are getting results. Please keep us posted on final results.Good idea not to do anymore modules till you have the 4 working well that you have rehydrated. You may get the code 2006(unusual battery voltages as the 4 re-hydrated modules adjust to the pack. Just keep resetting the code and drive gently till they settle in.
Best of luck

Roy

If you can post the pictures of the battery tray before and after painting it may help others who think there is no corrosion occuring when the p3009 code is showing and everything looks clean. In a severe grounding holes have been burned in the case.

 

This an update as of July 16, 2015 - I have been running my car for about a month now with the 38 modules I rehydrated in place and in the car.

The slightest amount of liquid from the hydrated battery will cause P3009 ( ground fault) to occur on even cells that I had cleaned with soap and water and then fresh water and dried them well. I finally had to remove all the modules from the battery again and scrub them with a solution of borax (borax will clear away the battery solution better then just soapy water). If you have any spillage during the hydrating process be aware that unless the module is cleaned properly it will leak current to ground and cause the code P3009.

Borax can be found at the grocery store - it is used to clean clothes when added to the wash when doing the laundry and is called "MULE 20 TEAM BORAX - NATURES FRESHENER". Do not immerse the module completely in the solution as it will cause the positive terminal of the module to activate and remove the nickle plating on the connection - this was the only way I could stop the code from coming up.

I could stop the code by unbolting the complete battery and sitting it down on a rubber mat to isolate it from ground - I ran the battery a few days like this to be sure the leak was from the battery ground and not a ground somewhere else in the cars electrical circuitry. This is not a safe way to drive the car as the battery is not bolted down to the body of the car and I do not recommend you do it. This 2001 prius car is used for experiments and I am in the only one ever in the car while doing the testing.

Roy from Canada

 

Again, I find this thread very interesting, just happy to read along.

Regarding the Borax brand, it's "20 Mule Team", as in: there's a team of 20 mules, pulling a wagonload of Borax.

 

Yes Medal you are right - even though I quoted the box label as seen on the box. This cheap cleaning prouct contains a product that will clean the batteries so they will no longer conduct electricity over the body of the module,

 

Hi Roy,
Any thoughts on how the re-hydrated modules are performing? Did you use first or second gen modules? Have you done any capacity testing?
Brad

 

Hi Brad - I have 38 newer ( Gen 2 type 2004 up) modules installed in a 2001 prius that I drilled, hydrated and sealed in the car. I was foolish to drill holes in the modules and not seal them up immediately - instead I drove the car for test runs and the cells started to boil over under the test. spilling liquid out of the holes in some of the modules causing the p3009 ( grounds}. I have removed them twice to clean them, the second time with Borax.
I have not tested any of the hydrated modules individually but the hydrated battery holds its charge (ie it does not drop as much voltage) compared to my other 3 cars that have the original Gen 1 modules installed. This is my up a steep local hill test. However I am going to remove these hydrated Gen 2 modules and replace them with 38 non hydrated Gen 2 modules and do the uphill test again. At that time I will test the hydrated modules (probably a month from now). Over time I plan to convert all for cars to Gen 2 batteries. Before re-hydration the cells had readings in the 5000 to 5500 mah range.

Thanks for the suggestion to use a hoyer lift. I bought a used one and removed its lifting arm and made up a longer one plus counter weights that allows me to reach into the trunk from the rear. I can now remove a battery in a few minutes once the fan housing is removed and it has saved my 76 year old back. Removing the battery by myself before was a big pain now it is real easy.

I caution everyone about the leakage that may occur on filling the modules with water, any spillage will cause code p3009, even after cleaning with soap as in my case. I think I will use a little less water the next time when filling the cells.

 

I have been driving my 03 that I in which I re hydrated 5 modules several months ago...it threw a code which I cant remember but it was uneven battery ( I think) over and over again....and now finally, it appears that the battery is balanced. Roy is absolutely correct, even the slightest amount of liquid, (water, hydrating fluid) will cause the code to show up. Hydrating in place is tenuous, and even a few drops spilled will result in the voltage leak. It was a pain to remove the battery and disassemble each module for cleaning, but it must be completely dry. Moreover, the battery is stronger, the weak battery bank DTCs are gone.

 

I've read through this entire thread and it's pretty interesting. I have two GEN II batteries I'm currently reconditioning. One had two defective modules and they were replaced. After reconditioning that battery, all modules are ~5500 mA, give or take ~300 mA. The other hasn't been started yet but not so optimistic about it. The resting voltages are all over the place.

Realizing that there's more than one way to accomplish the same task, as well as varying degrees in which people want to attack that task, I'm interested in trying to hydrate the modules with boiling water only. Toymo's approach seems to be what I'm looking for. In summarizing the steps, is this fairly accurate:

1. Drill one hole in the top of each cell (6 per module).

2. Inject 5ml/g/cc of boiling water into each hole.

3. Wait ~1hr.

4. Seal the hole with a self-tapping screw (type of metal?) and perhaps and o-ring or gasket.

5. Cycle the module 2-3 times and verify results.

 

Thanks. Would you suggest countersinking the holes and using a tapered screw or just go with pan head?

 

I'd be curious to see the result because I think we'll find adding a KOH/water mix will be more effective in re-hydrating (since just adding water may dilute the PH too far, much of the KOH forms a crust inside the vent space) but it needs to be verified to be sure.

 

Hmmm since we can't use the vent to get the water back in a koh mixture might be more effective, if we could use the vent, I.e use a vaccum to cause the valve to trigger and sneak the water in on the sides that would not be a problem (koh is very water soluble.) But at this time we are drilling holes in the casing right?
terramir

 

Hi!

How did you reassemble the battery pack?

I refurbished the modules, but can not get them to fit back together. First ones suit perectly but the more I install them the bigger the caps get between them.