I hope these little fellows aren't too "lite" for this forum, but I need a bit of help if anyone has any experience with them...

I have four of these units, and it appears that the batteries have about given up on 3 of them. They've languished in storage for the last year, and when I tried them lately the run times were only about a minute, instead of the 10-15 minutes they used to run for. The two-cell battery pack has 2MR80AAA SH4PNIMH on it, but I have no clue what that means or where I might find a replacement. Has anyone else had anything to do with these, or know where to get a battery like this?

Thanks for any help or info anyone can provide.