So I want to power my Bushmaster MKII and Temple Audio Bantam Gold via battery power. I'm looking at one of these external batteries. It looks like it only has one DC out so I'd need some sort of splitter. Both the Bushmaster and the Temple Audio have 2.1mm power ins. Which sort of cables would I need to make this work? Can I buy them pre assembled and if not can someone diy it for me?