Well, one of my helpers has the 20v Dewalt Impact and Drill set. Today was the first cold day we've had this year, and his 20V Dewalt tools wouldn't work. The battery in the impact was charged up, but the drill wouldn't go. He tried to charge his other battery on the power pole outside at the site, and it wouldn't charge. It was flashing a trouble code at him the whole 3 hours he had it plugged in. It was 10 degrees and sunny here this morning when we started, and 30 degrees when we left.

I loaned him my Makita impact gun, which worked just fine.