Well! If the battery is there then the SM-BCR2 should always display a light, as far as I know. Either the error led (red / flashing), or the orange charge led.
I don't think both your battery and BCR2 are dead, but just one of them (or something is disconnected).
It's just that I've not connected a BCR2 to a known-dead battery myself before, so I'm not sure what it'd do
