Can Ni-mH battery have a battery life indicator?

[Sonyportableizer]

Can I get thing I use with the battery pack so I can tell how much battery life is left?
And if there is, links?

 

[Aux]

Yeah, but you're going to have to do some circuitry physics. It depends on how many volts you're running at and what you want to do- one LED that comes on when it's low, a whole bar that goes down, etc.