I'm having issues regarding my

Question

I'm having issues regarding my CMOS battery. It seems to only last around 3months. I sent it back to where I bought it from, and they said they flashed my BIOS which has solved the problem. But 2months later and the battery is flat again. I get a cmos checksum error at startup.The motherboard is a foxconn P9657AA-8EKRS2H.Can I do anything at home to resolve this issue. Or will I need to send it back again. As it's not fit for purpose can I ask for my money back after 6month? ThanksDJ.