I'm betting that your batteries cannot hold a full charge now. If you haven't replaced the batteries in over 5-7 years, it might be time. If you go in battery mode how long do the batteries last before switching to AC? I think you might find its a shorter period of time than you were used to.
When I had my batteries replaced, JRDG did it quickly if I remember the cost was around $120 with shipping.
When I had my batteries replaced, JRDG did it quickly if I remember the cost was around $120 with shipping.