Back to the drawing board.

I'm really curious how in the heck he is charging at a 2A rate, because once the batteries hit about 8.6V, they start to slightly swell at any rates above 0.5A.
My charger cannot cutoff at a certain voltage, misses the delta peak, etc. There's no way I could feed my modules 2A without them turning into balloons, or unless I literally sat and looked at them until gaps appeared between the modules, indicating swelling, but that would be like watching paint dry.

 

The modules are bolted and clamped in the factory setup.
When I mean swelling, you can visibly see gaps between the modules that increase in distance to about the width of a credit card when they do swell.
You can see what I'm talking about in the first post on this thread.

 

Did your charger automatically end? I had the blower from the Prius itself blowing on the modules and they still slightly swelled.

Since the heat source is internal, I can't imagine being able to cool the modules down enough to prevent swelling, unless you had them inside a walk in freezer or something.

 

I had made that error initially but have stopped charging the modules together. But honestly I don't see how it makes much of a difference when grid chargers charge them all at once.

I used some left over electrical stuff I had and made some ends for the discharger which can now be bolted on, no more messing with alligator clips. The issue with the discharger is that if it detects a voltage below 5.4V AT ALL, it shuts down and has to be restarted, so even slightly bumping the clips once installed will trigger that.

As you can see below, I can now bolt the connectors on, and am using one of the copper bus strips for the other side of the modules.
Before you ask, NO the large 200A blade fuse is not part of this lol it's for something on eBay I'm selling.

 

Found a way to kind of speed things up, as long as I'm not busy and can babysit.
I notice modules start to slightly swell above 8.75 volts when current applied is over .6A.
So what I've been doing is charging the modules at 5A with my voltmeter attached, and once the voltmeter shows 8.7V, restarting the charger at .6A.
It would be nice if they made a programmable multi stage charger, where this could be done automatically, but that would probably not be cheap.
Also something strange I noticed, when I let two modules set overnight with .5A charge applied, one of them measured 9.9V with my voltmeter. Never seen one get so high, but no swelling, and discharged over 4,000MAh, so all is well.
Above the high cutoff voltage of the modules, excess current from the charger is dissipated as heat, as others have said.
There is probably a "magic number" of amps that starts to cause swelling, which is at least 1.5A, but at .6A, you can leave the charger on for 10+ hours without swelling.
I am still not sure technically speaking..what voltage of the module is considered charged..as the charger does not shut off due to missing the delta peak. 6V is technically considered the bottom cutoff voltage. I believe this number is 8.7, but as I've read..if you continue to charge for several hours over this, it will perform what is called a "form charge" which is crucial to the refresh process besides discharging to around 3V per module.

 

Welp, back to the drawing board yet again. I accidentally reversed polarity on the discharger, and instead of blowing the fuse on it like it was supposed to in case of a RP situation, it blew out a surface mounted IC chip. So now I'm going to have to order another one. ..

 

Alftoy, I tried to PM you, but it won't let me.