Any specifications (e.g. minimum runtime) or explanation of constraints (e.g. limited mass/volume/budget) would be appreciated.
Sorry. Minimum runtime would be 2 hours. My constraints are that the entire package needs to fit inside a block of wood with maximum dimensions of Height: 1.25", Width: 1.75", Length: 7.0". The total weight (electronics plus block of wood it will fit inside of) is 5 oz. I plan on hollowing out a large part of the inside to keep the overall weight under the 5 oz. limit.
I think that should do it. If there's any more information you require, let me know.