After a few years of use a battery pack may not charge anymore or lose its charge after just a few minutes. We recommend immediate replacement of the internal Battery Cell. Kit includes Battery Cell (6V), Foam Pads and 6 months warranty (on parts only). We do not recommend users to replace the cell on their own, otherwise no further warranty would apply. If you agree and wish us to replace the battery cell please scroll down to Related Products and select the complete service.