For how long can the Raspberry Pi run when powered from a battery of a given capacity?
Of course this will strongly depend on how it is used and what devices are connected, but I am trying to get a rough estimate for my use case, to be able to decide what battery to get (while trying to keep the budget low, I don't want to go straight for the 12000 mAh option unless necessary).
I am using it to take a timelapse with
raspivid with 2 fps. CPU usage is always low (< 10%), but I guess GPU usage and the constantly active camera influences the battery life too. No devices are connected except for the Pi camera. Perhaps someone already has experience with a similar situation.
Alternatively, how can I measure the power usage of the Pi under actual usage, to estimate the battery life myself? I do have a multimeter, but breaking the power circuit and inserting a multimeter to measure the current seems like a lot of trouble, especially since it would involve destroying the power cable.