Amazon.com : BoxWave Charger Compatible with Nikon D3100 (Charger by BoxWave) - Digital Camera Battery Charger, Car Charger for Camera Batteries for Nikon D3100, Nikon D3100 | Coolpix P7000 : Digital Camera
Amazon.com: UltraPro Nikon D3100 Digital Camera Battery Charger (110/220v with Car & EU adapters) - UltraPro Replacement Charger for Nikon MH-24 Charger : Electronics
Amazon.com : Neewer Professional Vertical Battery Grip Replacement for Nikon D3100/D3200/D3300/D5300 SLR Digital Camera, Works with 1 or 2 Pieces EN-EL14 Batteries : Electronics
Amazon.com : BM Premium Pack of 2 EN-EL14A Batteries and Charger for Nikon D3100, D3200, D3300, D3400, D3500, D5100, D5200, D5300, D5500, D5600, DF, Coolpix P7000, P7100, P7700 Digital SLR Cameras :