Mrs B forgot to buy D cells for Miss Borg's robot arm kit, so I spent a happy hour diking[1] and soldering[2] a 7 cell nimh crane stock battery down to 5 cells /~6V, then crocodile-clipped it in to power it up.
Needless to say: BEST CHRISTMAS EVER.
[1] http://catb.org/jargon/html/D/dike.html
[2] 59.5 minutes swearing at Chinesium peasant solder, then 30 seconds getting it done with German master race solder.