The rechargeable version of the 3700 with mutliple options for charging. The Fast Charger System comes with a 2-bay charger base: a fast charging bay for the Big Ed (with battery pack installed) and a trickle bay for a spare battery pack (not included). It also comes with a 110V transformer. The Trickle Charger System comes with a trickle/trickle charger base. It is available with either a 110V transformer or 12V plug-in adapter (for vehicle installation). Another option for vehicle installation for the Trickle system is with a direct wiring kit accessory.