Definitely shop around. Anything that calls itself a "Solar Generator" or "Solar Ready" should have its own controller built in. Also look at Watt-Hours, because Ah are a pretty easy way to hide krap batteries. Is that 135Ah at 12v LFP or 3.6v 18650Li? That's the difference between 1620 Watt Hours and 489 watt hours. Same number for marketing, WWWAAYYY different capacities.