Defibtech Lifeline AED features 2 types of battery options. The replacement battery pack is available in 5 year life battery and high capacity 7 year battery (installed in the unit)(including daily, weekly, monthly and quarterly self-tests). Defibtech AED's also feature Adult and Pediatric defibrillation pad options. AED4U.com features Defibtech AED pads and batteries at low prices.