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
BATTERY GRIP D3100
Rapid Quick Charger for EN-EL14 Li-ion Battery compatible with Nikon D3100 DS... - Audio Video Nation
EN-EL14a Battery or LCD Slim Charger for Nikon D3100 D3200 D3300 D3400 Df DSLR | eBay
Amazon.com: UltraPro Nikon D3100 Digital Camera Battery Charger (110/220v with Car & EU adapters) - UltraPro Replacement Charger for Nikon MH-24 Charger : Electronics