A top quality Inverter I have found out is called Daltron. The main distributor is called SystemTrust Ltd. They have offices in Lekki Phase1, and Adeniran Ogunsanya in Surulere. I bought a 3kVA 48V with 4pcs of 200ah Daltron batteries in January 2011 at N350,000 fully installed. It has been running smoothly and most importantly, our computers never re-starts at PHCN failure. The Inverter we used before was restarting our computers, until a friend recommeded Daltron. I was also told that it has a rugged surge protection built-in. I therefore recommend Daltron to you.