Replace your Garmin Nuvi 3790T Battery or Keep an Extra Battery on hand as a backup. This is an Extended Capacity 1200 mAh, Lithium-Polymer Battery that offers up even more up time than your original. Works in your Garmin Nuvi 3790T GPS. Simple, Easy and Inexpensive! You get a New Battery, Installation Instructions Video, Tools for Battery Installation, AND You also get a full ONE YEAR Money Back Guarantee exclusively when you purchase from us.