Assemble inverter with batteries

I purchased the Mecer inverter box kit without the batteries and I when I received the batteries, I was worried about connecting them to the inverter because the instructions look like there would be current going through it. So I managed to contact Garth via the communications portal of their website and he was very quick to respond and tell me to bring in the unit for assembly, even thought I didn't buy batteries from them. Thanks Garth and Sizwe for all the help, inverter is working like the instructions say it should.