for anyone who may be looking for a big DC-DC charger with solar input, the Projecta IDC45 which sells from around $450-550, East Coast Batteries currently have them on their website for $379
https://ecbstore.com.au/products/projecta-45-amp-dc-to-dc-charger-with-mppt-solar-regulating
https://ecbstore.com.au/products/projecta-45-amp-dc-to-dc-charger-with-mppt-solar-regulating