My Hybrid ROV just completed another dive in my Associations’s swimming pool. The object of this dive was to determine battery usage over a period of close to an hour.
I ran the ROV for almost an hour using Depth Hold, which caused the vertical thruster to run continuously, and applied moderate drive to the two horizontal thrusters as I circled the pool. I also tested the outboard lights as well as the inboard WTC Controller mounted lights. Both performed as expected.
After about an hour of moderate run time I found that it took around 1300 ma to recharge each of the two NiMH 9.6 vdc 4500 mah batteries. So I would say that I could safely perform a dive that could last around two hours and still have some battery margin left.