I bought Alesis SR18 in December 2017. It is been year and half and system is showing low battery. I checked with local dealer and they said this battery is not replaceable. so, I have through this item now. Since I bought it, I have spent huge time to make my own beats and all are gone. I am really frustrated now, and I am not under warranty. I do not understand one thing, why Alesis made this kind of device which will not last event two years.? SR 16 has an option to replace the internal battery but SR18 doesn't. I dont get it. So, I am worried to buy any Alesis product in future.