Picking up batteries and rudder

Shaft and propeller A colleague at work - Christoph - invited me to his BBQ party tonight, which is nice, and what is even nicer is that he lives at Emsdetten, gave me a lift to his place, and stopped over at the model shop for me. There I got the lead acid batteries (1 x 12V/12Ah, 2 x 6V/12Ah) and the rudder, setting me back by EUR80,-.

To be fair, that still was a deal, but I inhaled sharply. I'm not so sure any more if I need the capacity, and whether the computer and propulsion couldn't share power. On the other hand: the engines probably introduce a lot of erratic signals on the power supply, and I might want to execute longer autonomous cruises. So let's see how it works with weight and volume. 8kg of batteries will make the ship pretty heavy....