I went back to Home Depot for a third time and this time we tested the battery. The third unit also did not blink when charging and the green light in the back of the battery was only showing one light. This was a very disappointing experience. This was my first Dewalt product and now my confidence with them has gone down.
They had a Ryobi battery blower at the store that has a little less power but it was $50 cheaper.When I plugged in the battery to their charger, it blinked and the green light on the battery in the back showed it was charging. Oh well. Live and Learn.