"mike" wrote in message
...

Make sure you're comparing apples with apples.
The unloaded voltage of a cell is irrelevant.
I've found it very difficult to get the unloaded voltage of NiMH below
1.2V. Discharge it down to .8V, remove the load and let it sit and
it will creep back up to 1.2V. But it's still dead and can't supply
much current.
A flash is a VERY high current device. Once the LOADED voltage gets
much below 1V, it's too weak for a flash. The ONLY useful voltage
measurement is with the intended load.

A useful measurement is internal resistance. Use a square-wave load from
1/2A to 1A. Measure the P-P amplitude of the cell voltage and use that
to calculate a resistance dV/dI. Try it at different states of charge.

Calculate the voltage drop from your load current and the ISR.
Multiply that by the number of series cells and it's easy to see
why high-current loads quit working long before the open-circuit
voltage gets below 1.2V.

I shouldn't have said anything about the voltage.

The point is that the cells "should" have been dead, but weren't. After
nearly two years, they powered the flash to its spec's number of flashes.