Redarc does have the solar capability. Check out some of there other products. They operates with anything from 9 to 32V input and can operate with a different inputs for solar and change to TV start battery. Check out this product it operates off solar as an MPPT solutions, but then switch to TV start battery as a step up battery charger.
I have heard great things about this solution:
http://www.redarc.com.au/images/uplo...ger_130408.pdf