I came across a reference to Maximum Power Point Tracking charge controllers in an older motor home magazine. What these do is allow the solar panels to continue to charge the battery under low light conditions (dawn, dusk, clouds) where panel voltage falls below the set point of the battery. You can wire your panels in series rather than parallel thus getting a much higher voltage to the controller. I my case I could wire the 4 x 12 volt panels in series and get 48 volts, or in series / parallel to archive 24 volts This also lets you use smaller wire from the panels to the controller. The controller "sees" and tracks (15 times a second) the changing voltage giving (they say) about 30% more wattage into the battery in any given day. With my 60 watt (5 amp) system a controller like these would work https://genasun.com/products-store/mppt-solar-charge-controllers/mppt-for-lead-acid/
Note that these have 4 stage battery charging with desulfation and do not produce radio interference. There are a number of brands and sizes (and prices) of these " Maximum Power Point Tracking charge controllers" that you can search for on the net.