I was going to say you need a few treatments or a 72 hour tops in one session. It takes 3-5 hours to just charge the battery before the balancing begins. At a low amperage continious charge it ensures all cells are in ttip top shape with each cell being 100% charged vs close enoughfor government work so to speak.
The charger should run the fan in the IMA system to keep the batteries cool. Me, I have a dumb/dumb charger so I use another charger on my starter battery and I use a beach key in the ignition to turn it on so the car minds the battery cooling as needed and the dumb charger does its thing. Took my 36 hours and terminate at 122.5 volts for 84 cells of the gen 2 insight.
Its important to check the voltage to make sure it works. You should also try it unplugged to see the no load voltage. My no load voltage is 134 volts. When Charging starts its around 107 volts, then it goes up to like 128, then it settles down to 121 or 122. Thats normal for it to rise, then fall, then it settles at a fixed voltage. Thats why I asked if you checked it every 15 minutes to make sure it didnt change. Thats how you tell its done.
Another guy makes a smart charger that does all this for you including a discharge cycle and works on all hybrids not just certain models.