Primary german torpedo was the type G7e. It was an electric torpedo. Meaning it used lead acid batteries to power it to around 30 knots. early models of the G7e had a range of 5,470 yards and the late war model had a range of 8,200 yards at 30 kts.
The G7e was a very good torpedo that was copied by the USN, with their Torpedo Mk 18. This was a modified version for USN service.
here is a link to German WW2 torpedos from the
www.navweaps.com site
http://www.navweaps.com/Weapons/WTGER_WWII.htm
hope that helps clear up some things and questions about German torpedos.
CinC