I have a fairly new (1 year old) DeWalt lithum ion battery that now refuses to charge. Therefore, I contacted DeWalt for battery replacement under warranty. DeWalt was very helpful and here is the support transcript: Me (3/11/2019, 11:30:44 AM): Hello, I have a DeWalt 20V lithium ion battery that I need to replace under warranty. Paula D (3/11/2019, 11:30:36 AM): Thank you for contacting DeWalt. I’ll be happy to assist you today. Me (3/11/2019, 11:30:44 AM): Thank you Paula!