mosfet wiring question

[windxrunner]

but as long as I do not put the batteries in the wrong way, that is fine? i am always very careful when I insert batteries.

 

[somun]

Then you should be fine. Of course you need to connect the negative terminals of the batteries (or battery holders) as well.

 

[Dampmaskin]

I don't think that diagram is correct. It would not work properly. N Mosfet should be used as a low side switch.

Yeah, you're right. My bad. The atty should be connected to the drain.