Hmmm, ryobi batteries... Might want to step up to Milwaukee. While the same company in China makes both ryobi and Milwaukee, the ryobi stuff is not "just as good"...
Taking a 870 apart is not as easy as a moss 500. I have multiples of both, and I prefer the Mossberg for the weight reduction. I'll never shoot either enough to wear them out.
For what those batteries are used for, they are adequate. I never made any claim that Ryobi makes top end tools.