I have a 2 battery with smart isolator set up. My second battery is an Odyssey PC925. When charging both batteries at the same time, once the stock battery reaches a charged level, the isolator kicks in and connects the batteries. No big deal if using trickle charger. I just purchased the Odyssey battery charger which is specifically for Odyssey deep cycle batteries and supposedly not to be used on other batteries. I want to put a battery disconnect switch on the Odyessy battery so that both batteries are phyically separated when using the Odyessy charger. Should the switch go on the negative or positive cable of the PC925?