Hey Guys, As you may know, The Craftsman 20v max Bolt-on system is the same exact battery and is interchangeable with the Black and Decker 20v Max. I did exactly as you described. I took the cells from an old laptop battery (LGES318650) and soldiered them into the Craftsman 20v max battery case. Replacing the bad LI cells. It works! no heat, no real problem. The ones in the case were 18650's @ 1500mah. The ones from the Laptop are 18650's @ 2400mah. I soldiered them in my drill battery case and charged the battery. It works great. Just as long as I pull the trigger slowly from slow speed to fast speed it's perfect. However, pull the trigger fast, asking the drill to go full speed, "uh NO! I can't and I won't." Does it have anything to do with the difference in mAH rating? The originals are 1500mAh, the ones from the laptop are 2400mAh. it's like the battery cells wont deliver high current at a fast rate. But, they will deliver the high current if you ask nicely. Thanks Dan