Sennheiser SKM5000 with two AA batteries.

The graph below shows the comparative battery life of various AA batteries in a SKM5000 hand held transmitter.

The SKM5000 graph cuts off at 1.7 volts which is where the transmitter stops operating. The lines at 2.6 and 2.2 volts show where the battery sled indication changes from high to medium and medium to low respectively.

This is the only transmitter where rechargable Nickel Metal Hydride batteries were tested. It can b e seen that they were exhausted as much as 4 hours before the majority of the alkaline chemistry batteries. The cost savings of rechargable batteries must be weighed against the operating time and the chance that they may die during a performance.

Also the lithium chemistry battery lasted approximately 4 hours longer than the alkalines. The cost for lithium batteries is significantly higher, but there are applications where batteries simply can not be changed during a performance.