They are amazing, the battery life is absolutely insane on these... I think I've charged mine maybe from red, maybe at most 5 times since I got it July of last year.
i ordered 2 SNES30 and 1 SCF30 (Famicon) can't wait to get em all in and use them for Mario Kart 8. Gonna bring back the good ole Super Nintendo Mario Kart days for me n my buddies.