lowbreaker

I am experiencing this exact same issue. I already knew that this unit was designed to use 8.0 batteries and higher, as the 5.0 batteries will drain very quickling and overheat....so i have ONLY been using my included 8.0 battery and a new milwaukee 12.0 battery i bought separte. Both have the same melted terminal as show in previous posts. Now if i try to use these batteries with the melted terminal the power head will function but wont trim under any load whatsoever. This is a shame cause i really was impressed with that last two months using this trimmer and polesaw until today!