Hotel/B&B
There are a few B&Bs close to the Franklin district of Mannheim. The adjacent district is Mannheim Käfertal and following direction city center there are many options in various price ranges. You could also consider the NH Hotel close to the Rhein-Neckar-Zentrum Shopping center which 2 stops away by tram No 5.
list of hotels and B&Bs:
Touristeninformation Mannheim
AirBnB community marketplace ->Mannheim