Not sure...just the things I saw on YouTube. I bolted all the modules in except one, which was the last I charged and was still slightly "puffy". It took around 2 days for the last puffy module to return to normal. Since I the patience of a puppy with ADHD, I planed down a board to the thickness of the module so I didn't have to wait 2 days before charging more modules. I then bolted the rails together. I also took the ends of the RC charger, which are kind of close together, and soldered the alligator clip leads to them, and put some heat shrink tubing over it. I put the module pack on some 2x6's to keep off the floor for cooling. I'm also making sure to charge modules at some distance from each other to mitigate heat. This is now the setup. After the 1st charge cycle, the two modules I charged are 2534 and 2596 MAh. Hopefully they will improve after two more cycles. I am not sure what the pass/fail is for capacity, I think 4000 MAh?
I did some more reading on the discharge rates..and some people seem to use the same load (headlight bulb) for the same amount of time to record the before and after voltage. But some people instead don't do this, instead taking the modules down to 6 or 5 or even 2-3 volts, by way of using the discharge circuit on their hobby chargers rather than a headlight bulb. Is there any advantage to taking the modules down to the same lower voltages with the charger or should I apply the same load for the amount of time with a bulb?
Well since no one answered my questions, on the 2nd phase of discharging I am using the hobby charger to discharge. My question is..is one supposed to considered the capacity shown during charging OR discharging as the actual capacity? I finished charging all 28 cells. Lowest capacity was 2058 MAh and highest was 3494 MAh, average was 2530 Mah. Also, on a positive note..I was able to get the swelling in the one module under control and now all 28 are back into the rails.
Some pointers from @TMR-JWAP Prius battery NiMh cells puff up a bit during charging - how to stop it... | PriusChat
I tried to use the hobby charger to discharge, but the issue is while this hobby charger, as well as my previous one has 5A discharging rate, when I use the hobby chargers to discharge with 5A selected, it seems to only want to put a 1.5A load on it. At that rate, it took over 2 hours to get down to 7.7 volts. So that idea isn't going to work.
I am not sure just how accurate the capacity reading is on these hobby chargers. Starting back with the first cell after it was discharged the second time, it's capacity is at 4500Mah and climbing. If you discharge a module down to say 7.2v and charge, and then again down to 5 and charge, the amount of time it takes to charge is of course going to be higher. Are these chargers just counting MAh by how long it takes to charge? Or is a more accurate capacity test to see how much voltage is lost after 2 minutes duration of an applied constant load (like a headlight bulb).
Here is my current setup. Using a large box fan to cool everything down. I can use the hobby charger to charge two batteries at once, and the discharger to discharge two batteries at once, right now I am taking two modules connected together from 14 to 8 volts (4v each) using .42A of discharge current. Oddly enough the discharger can auto ID batteries, but no matter if connected to one or two modules, it says each module is 7 cells and not 6.