Unfortunately I can't view Nvision's site on my phone, but looks like any of the other "4 button" clone chargers which all have some sort of NiCd/NiMh peak detection/charge cutoff. No experience with them but I'd assume you can adjust the peak sensitivity as well since NiCd requires a higher value for less sensitivity. Lowering the charge amperage I'm sure helped but 100min sounds too long and making the peak sensitivity more sensitive should stop the charge sooner.
Did a quick look to refresh my memory and around 5mV/C is the norm for NiMh. Either way going to a lower value will increase sensitivity. So if it's set for say 8mV/C, going down to 5mV/C will make it more sensitive and stop the charge sooner. This value is adjustable since not all batteries peak the same and false peaks or not detecting the peak is possible.
I've heard people stating how many mah went into their pack after a charge using these simple 4 button chargers so apparantly they're pretty capable. Try finding the peak sensitivity setting and lowering it to its lowest setting. Charge and measure the pack voltage after its done. Max NiMh voltage is 1.4v per cell, adjust the peak sensitivity until you're seeing somewhere north of 1.3v per cell after a charge cycle.
Last edited by Overdriven; 09-12-2016 at 06:08 AM.