I've been looking around at the various dual battery kits for my 2015 570. I came across this in a marine store.

https://www.bluesea.com/products/760...24V_DC_65A/FAQ

It says it isolates two batteries but allows charging of both. It is only $48 online and I am wondering if anyone with experience with these can tell me if this would work. It's priced a whole lot better than the $300 kits I've seen. In the store it's packaged as " Add-a-battery" kit.