Braun Oral-B Professional Care 9900 Triumph Ni-MH battery Replacement - iFixit Repair Guide
Braun Oral-B Professional Care Type 3728 Battery Replacement - ToothbrushBattery.com
Amazon.com: FDK OEM NiMH Replacement Battery compatible with Braun Oral-b Type 3731 or 3745 Toothbrush, with Narrow tabs (42L x 17D mm, 2150 mAh) : Health & Household