15.9v battery modules

I'm trying to replace a few modules and rebalance what I believe is a Gen 2 battery (G9280-47011). I see so many references to 7.8v modules but mine are 15.9v leaving me a little confused. This battery has 28 modules at 15.9v. What am I missing here? I want to run through the discharge and recharge cycle a few times to recover some of the capacity of these modules but without the technical specs to know how low I can discharge, how high to charge, at what rate, etc, I'm hesitant to do anything. I was given the replacement modules and they are also 15.9 volts. What gives? Any help would be greatly appreciated.

 

Wow! Can't believe I didn't even consider the issue was with the multimeter but you hit the nail on the head! 9v wasn't reading correctly either.

Thanks a bunch!!!