I too find that my 'old' batteries (from a previous P45+) seem to run down more quickly than the new ones that came with last years P65+ upgrade.
have even marked them to tell the two apart.
you are lucky if you get 2hrs with zero latency. I doubt I get that. 5 batteries x2 hrs is a 10 hour working day which sounds great to me.
however shooting on the DF camera, with normal latency, I get 400+ shots on a single battery, shot over 2-4 hours, which is good enough for me.
although... having a camera with one power source/battery, not two, would be better still. and lighter.