The Ravin Electric Drive Replacement Battery attaches quickly to your R500 Series crossbow, giving you an easy way to keep your electric drive cocking system charged up and ready to go. OEM Replacement Battery features a 3,000 mAh capacity and weighs just 800 grams. 12V lithium battery for Ravin electric drive cocking system Quick and easy to attach/detach For use with Ravin R500 series crossbows only 3,000 mAh battery capacity Weighs 800 grams Order today!