This is only a short update about the current status of this project. 

Right now, I am fixing a few flaws in the design files of the robot.

First, I changed the suction unit, because a lot of air still leaked out in some places. In addition, the suction opening underneath the robot was enlarged, because long hairs were still partly stuck. Then I decided to use a LiPo instead of a lead battery. I have written down a few important aspects which should be considered when deciding.

The main reason is that LiPo batteries are way lighter than lead batteries. For comparison, the currently installed lead battery weighs about 890g. It has a capacity of 2300mAh. The LiPo battery I want to use weighs only 219g and has a capacity of 2600 mAh.

Furthermore, the LiPo battery is only 2/3 the size of the lead battery.

Also an important note is, that LiPo batteries are somewhat more expensive than lead batteries. But the price difference between the lead battery and the LiPo battery for the robot is only about 5 euro. That’s why I think the price difference is manageable.