Verify the new battery fits in the compartment. I had to omit the battery clip, and exercise care how I routed the wires. Verify the ribbon cable does not need to twist or strain. I had to tuck the power controller well beneath the mother board. Exercise care not to short-circuit the power controller board to the mother board.

Observe that Jawbone did not follow the engineering principle of separation of functions. Jawbone used the battery as the mass in a mass-spring acoustic resonator. So the mass needs to be close to the original. I added a couple of dimes to make up for my new battery being light and discarding the battery clip.