Hi Susan, I repair power wheel chairs, Its possible that your chair has a bad battery on it , all p/chairs have 2 batteries.And even though you show a full charge one battery may have a bad cell in it you need to get both batteries load tested . I think you my find one of them bad. take them out of chair and have them tested.You can get replacement batteries , and have yours tested at a store that sells batteries only, look in yellow pages for a battery store . Good luck, Erik