________________________Applications Engineering Note

December 20, 2006

   Ansmann Energy GMBH Energy 4 Rechargeable battery evaluation

     Four AA and two 9-volt nickel metal hydride rechargeable batteries were evaluated for
    use in Shure wireless transmitters. The fit and operation were found to work well and the
    Energy 4 system has a 120/220-volt charger with interchangeable electrical plugs for use
    international use.

     •     Batteries coded #1 & #2, charged for 13 hrs to a voltage of 1.33 each. SLX1 ran for
           8.5 hours on day one and 3.5 hours on day two before the SLX1 reached a shutdown
           voltage of 1.9 volts. Note the SLX1 draws less then 30mA when off.
     •    Batteries code #3 & #4 charged for 10+ hrs to a voltage of 1.33 each. SLX1 ran for
           7.0 hours on day one and 6.5 hours on day two before the SLX1 reached a shutdown
           voltage of 1.9 volts. Batteries were removed over night
.    •    AA batteries #3 & #4 were fully charged to 1.27 and 1.25 volts and checked after 24
           hours and found to have retained a voltage of 1.20 each.

     Ansmann 9-volt batteries 250 mAh rating & Shure ULX1 Bodypack transmitter

     •      Battery #1 was charged for 13 hrs to a voltage of 9.8 volts and provided four
            continuous hours
     •      Battery #2 charged to 9.5 volts and provided 4 hours of operation. 
            The process was repeated two additional times with the same results.
     •     The 9-volt batteries were fully charged to 9.79 and 9.78 volts and checked after 72 
            hours and found to have retained a voltage of 9.43 and 9.37.


                                                                                                 Jim Rice, Applications Specialist
                                                                                                   Shure Applications Engineering