We'll all have to wait and see.
BUT theoretically, the LS is a 1-watt device. Of course, if it's overdriven, it uses more power.
2 x 123 cells have about 6000Wh available
2 x AA cells have about the same amount available
(it's tough to tell exactly as the voltage is falling as the battery is discharging).
We're seeing 2-hour run time from the Lambda devices.
We're seeing 3-hour+ run time from the Arc sLS (at 3000Wh on one cell).
It WILL be interesting to see.
Who knows what PK comes up with?
Cheers,
Richard