Perfect module resealing tutorial, for the rehydrating process.

What are you rehydrating the cells with?

Do you have voltages on cells before and after as to what improvements you've actually seen by doing this?

SM-G960U ?

 

The module rehydrating process is an amazing tool to keep older hybrid packs in a "like new" state

I'm curious how this is determined...are you measuring a modules maximum capacity prior to and after rehydrating? What equipment are you using for testing this?

What is great about rehydrating, is that it can easily be performed right in the car itself

I suppose this eliminates 'prior to' and 'post' capacity testing of individual modules, so how are you determining "like new" state?

Concentrate on weaker, problematic modules. Leave the stronger modules alone.

Maybe you're determining this by using an app like Hybrid Assistant or something similar to find blocks that are weak when compared to the other blocks?

What are you rehydrating with......? water, chemicals, chop a module open and use it's juices to fix several others?

Give us the details. I can try to duplicate it on a work bench using some marginal modules from my 'NFG' box and document the results with actual capacity testing..Now I'm getting curious, so I suppose I'll have to chop up a module or two this weekend....

 

Wear the appropriate PPE.

You don't want to get the electrolyte on you.

Always curious for data gathered safely.

 

Here's one from well over a decade ago for the gen1:

Gen 1 Battery Rehydrating Experiment Results | PriusChat

and gen 2:

Re-hydrating the battery modules. | PriusChat

 

I may go totally gonzo on this. I remember reading some posts by @Britprius a couple years back where he experimented with adding chemicals to modules. At the time, it seemed like WAY to much work for me to pursue, even for the fun of it. Now I'm thinking that I could clamp 28 sketchy modules, get test data on all of them, and then leave them at full discharge. Blow a hole in the top, add just distilled water and then cycle them again a few times and see if there's a significant difference. If so, then build a battery and put it in my car for testing. I would never, ever sell it to anyone tho. Wayyyyy to sketchy to ever put in someone's car, but ok to play around with in mine.

 

Whoa, @fotomoto snuck one in there while I was typing, lol.

 

Albert seems to be using 'module' and 'cell' with their proper meanings, so that would mean six drilled holes, six screws, and six glue blobs per module, right?

 

Yeah, I think if I end up doing this, the first thing I'll do is some super-duper destructive testing of a bad module to get some exact measurements. Then have at it with a drill. Six individual holes per module is probably the best way.

Wonder if I could put an "opened" module into my hydraulic press and squeeze juice out of it to add to the 'marginal' ones...a mini-car crusher type set-up....might be exciting if it's not fully discharged, lol....maybe I'll stick with distilled water, it sure sounds easier..and safer..

 

What, Bob's testing way back when wasn't destructive enough for you?

Might not be necessary. As I understand it, the 'juice' isn't what leaves, just the water, in the form of H₂ and O₂ escaping the seals. Leaves behind dried-out juice concentrate, which becomes the juice again when you put the water back.

 

A few questions:

1. The numbers without units are decimal inches? For example: "The 3mm screw measures .114 dia."

2. By "actual thread diameter" you mean outside diameter, out-to-out of threads? I'd assume so, but just asking.

3. The value .114 is then 3/25.4? I get .118, just doing the math. Appreciate that's a very quibbling difference. Also, it's kinda moot: whatever the screw diameter measures, you're saying undersize the hole by .01" (somewhere between 1/64" and 1/128". Or to keep it all metric, very close to 0.25 mm.

4. Did you consider using two-part expoxy? Or Super-Glue is effective, less complicated? The Super-Glue doesn't start to lock the screw in the last screwing in process?

5. I'd second the "what" are you adding, assuming distilled water?

 

I just have to try this again, I didn't waste quite enough of my life on it last time

Have a couple 4000mah modules in the last pack that I tested, will try with those!

My only question is which glue will work best, I previously found no glues worked that well for pp, holt melt sticks and 2 part epoxy nearly worked but still not that great!

More work on the glue and this could even become a thing to do!



Matt

Posted via the PriusChat mobile app.

 

Step 6, Albert mentioned exactly how he sealed the screw against the PP. Maybe try his way instead of reinventing the wheel.

 

Just wait 'til the "rebuilders" get drilled modules back as cores... OMG!

 

Was just saying superglue was the least effective of all the glues that I tried last time I done this, maybe it comes down to what sort of superglue or the way it's applicated, I will give this way a try nothing to lose!

Very interested to find out if the koh wicks it's way back through to the surface after a few months

Posted via the PriusChat mobile app.

 

Mentioned this in the other thread:

Goes without saying to clean around the drilled hole before resealing with the screw. Also cleaning with isopropyl alcohol will also slightly soften the PP, gives the super glue some tooth to grab better.

 

Has anybody tried using a relatively wide flat bottomed screw and sealing the space between it and the case with RTV?

My son has been working on an RV a lot this last year and RTV was used to seal many small gaps. It seems to be very good at sticking to many substances and worked in several instances where preformed gaskets did not. It will certainly stick firmly to the metal screw, but perhaps not so well to this plastic? The biggest difference I see is that in all of those cases there was a macroscopic "gasket" formed, at least 1/4" wide, whereas in this case the area under the screw head might not be so large. Still, there are pan head screws with very large heads.

https://www.ebay.com/itm/393575622571

If it doesn't stick when the plastic is perfectly smooth, one could make (or buy?) a bit to machine concentric small grooves into it for a better grip. Among other things, that could increase the surface area under the RTV by a factor of 2 or 3.

On further consideration, perhaps the problem is that the top of the module flexes up and down under operating conditions, as the pressure changes? That would be a very difficult surface to seal against!