Our family bought this inverter + bettery combo 3 years ago and its still working fine, no problem at all, not a single problem. Inverter charges the battery very efficiently and the sine wave feature also good. it has cooling fan inside which keeps the temprature of inverter low and stop it from over heating. it also auto cut charging when the bettery is full. it almost has 0 cost maintenence. Its very good product from microtek. In my case, this inverter turns out to be best inverter because it never gives problem single time. I really recommend to buy it. Rest its your free will to buy it or not.