First get the batteries checked out. 150 Ah isn't a lot but I have a single 95 Ah grp 27 running our trailer and the furnace always runs a lot. It and the solar is all we need in decent weather unless we start running the big inverter.
I know I would hate to have to plug in and use our cheap converter, even more so if I had fancy batteries. Make sure yours is functioning and has the features available to take care of those fancy batteries.
The solar obviously needs to be upgraded if you want it to cover your needs but you will need to know those before you can move forward. I estimated our by simply watching the daily voltage drop over 3 seasons. It ended up being useless not because it was a rough estimate, but because once we got the solar we stopped conserving, got a big inverter and quadrupled the amount of power we use.
When you do start deciding on what to do, make sure all of the batteries, converter and charge controller play well together. Reading threads on AGM and the hassles they are to keep happy keeps pushing me back to FLA when considering the replacements for our banks.
Last thing is to go thru and make sure all of your connections are clean in your current set up. One corroded connection can cost you a lot of power. ( I see that was mentioned. lol)
