Hello mate - nice bit of kit. I was interested in it so had a read up. I was also surprised that you would need to wire this sort of device into the ignition circuit.
Thing is, I don't think you do! I'm not sure though, so maybe someone else here can confirm. Here's the manual...
http://www.autoelec.com.au/assets/broch ... -UK-EN.pdfLook at the wiring diagram on the right of page 8.
As Battery-to-Battery charger, you only need to connect the device (suitably fused) to your starter and leisure battery positives, then earth the device.