The kids kept losing the little clip that holds the battery in. Got sick of buying a full set of A Parts just to replace the clip.
Just shape a peice of 10mm ally bar (from B&Q) as shown in pics - easy. Held on by existing step screw and a body clip, can't get lost.
I guess you could also use a bit of thick plastic card or an old credit card!
If you liked those pictures, you should see these...