Halloween // Best battery-efficient pumpkin lights?

Any recommendations? I bought some of the medium-sized plastic pumpkins from Target last year, kept them on all night, and they ran through their batteries in less than a week. (Had no issues with the small pumpkins, though, they were great!) Thinking of just putting some additional lights inside of them that won't guzzle batteries and can be controlled from a distance.

So I'd like:

• lights that will last all night for at LEAST a couple of weeks

• timer and/or remote controlled

• flickering is nice but not necessary