For several years, on weekends, I've been building a cabin on a remote mountain lot that does not have any 110v electricity. I have used Ryobi 12 and 18 volt tools to do all the construction. I have a solar panel that keeps a large battery charged and I use that to recharge the Ryobi batteries. Most of the time the Ryobi batteries go all weekend without needing charging. The drills and circular saw in particular have really been put to the test and passed with flying colors.