Battery disconnect and Backup for tow vehicle (Ford)

I use a disconnect like this from Amazon it's low profile and on the negative post of the battery. I have only power from the battery to my Patriot Braking System via a 12volt power socket and cord before the disconnect. The reason I used the negative post was ease of installation vs the positive post. We have not had a failure to start since I put this in on our 2014 Flex, before 6-7 hours towing would need a jump. I charge the braking unit every two days.