As we know that now a days there is a very big problem of the electricity. This problem is increasing day by day so the sum kam invertors is one of the best way of preserving the energy. This has the capacity of charges more and more and work certain for a long hours. They requires 1 or2 batteries but I suggest to buy this invertor this is one of the best way of saving the electricity. And electeicity it is very important to use it carefully otherwise this is very harmful for us they may gives the electrick shorts tooo.