Also, a solar controller can only guess at the batteries true state. you really need a separate battery monitor that has a shunt on the negative pole to measure actual current in and out, along with a wire to the + terminal to monitor battery voltage. I'm using hte Victron SmartShunt, which is bluetooth only, so you check on it with an app on your phone. Victron and others make similar units that have a dedicated display for basic battery state as well as the bluetooth interface for more in depth info.
With the smartshunt, I need to configure it for the type and size of batteries I have, fully charge them with the power converter, then 'synchornize' the shunt so it knows thats 100%, and its good to go.