A big thank you to the both of you. Based on your suggestions I did some additional research and I think I Lithium-ion batteries are the way to go for me. They offer a (relatively) low charging time, yet have the density to power the robot for at least some time. Luckily, one of my business clients is a battery wholesaler, so I think getting the right battery shouldn't be much of a problem.The only (major) drawback I can think of is the danger of damaging the cells (I've seen quite some interesting videos of exploding batteries today . How do you handle this? From what I understand most of these battery packs have some sort of protection against under-charging or over-charging. Is it safe to rely on this? Or do I need to build in some extra protection that cuts off the power when below or above this threshold? Is this the same method that is used in the batteries of my laptop for example?
Then I would like to share a wild idea I had: I'm not sure if it's feasible at all, but would it be (theoretically) possible to program the robot to return to a specific location for a recharge when battery power drops below 10%? I was thinking about creating a charging station that the robot tries to find using its compas and IR receivers (the base would need to send out an IR signal that the robot can pick up to align itself correctly). Then the robot slowly drives into the charging station, connecting the battery pack to the loader using a regular barrel jack connector. Of course the robot needs to be perfectly aligned. From the software-side I think it's doable (I'm a software guy, quite new to all this hardware stuff , but what are your thoughts? Would be pretty cool to have a self-supporting rover driving around the office