I'm taking a look at the new Tracer AN Solar Charge Controller from EPEver. I compare it to the Tracer A series which I've been using for a couple of years and find some nice improvements, and a little issue.
Reviews, tests and even building your own! If you want to use solar panels to charge a battery you'll need one! They start simple and can get quite complicated - these videos will help you understand what they do and hopefully which type to buy!