Douglas

I have an M12 Propex expander tool that was, until today, working fine. Now when I put in a known good battery, the led lights countdown 4,3,2,1 and then show 1 and 3 on red, 2 and 4 off.(counting from positive to negative), and the work light flashes. The tool is otherwise dead. Anybody know what this means? The only thing I can find via google is that alternating 1,3 and 2,4 (aka christmas lights) means an over temp battery. I cleaned the battery sensor contact jic, but no improvement. --Doug