+ and - 12 V power supply with 12v Batteries, How to make a ground rail with both batteries
I have two 12V batteries and I'm assuming I just connect the positive terminal of one battery to the + rail and the - terminal of the other battery to the - rail and the remaining battery terminals connect to the ground rail. 


That's the correct way to do it.







simulate this circuit &ndash; Schematic created using CircuitLab

Figure 1. The schematic version.


  I'm going to use a 3 amp fuse on each battery for safety. 


Good idea.


  I'm quite a noob so there might be something obvious I'm missing here or doing completely wrong.


It looks fine so far.