Bad news: I haven't measured yet, but they look like they may be A cells, not AA, they're a larger in diameter . . .

Good news: they're about as much longer than AA that off the shelf AA rechargeable bats could replace the tabbed cells in the battery . . .

. . . an interchangeable externally rechargeable cell pack from the standard 190-Kanga BatPack might work! }

Edit: what's the voltage of these stock cells? If it's 1.5V we've got a winner:

Confirmed: Three standard CrapShack serial AA battery holder packs (parts from four would be easier) will be NoPro to install sideways in groups of six cells. Three AA cell holders would be perfect, use two as hinged (duct tape! [}] ]'> )barn doors on bottom or top of the casing with the standard double row clip offset and all is very, very