I like the cardboard box idea, operates on the K.I.S.S. principle. But, I really would like to have at least a micro power panel--I have a tendency to forget to charge the ni-starter, which I need for the glow plug heater I have. This way I can pop it on the charging lug for a few minutes if I forget. But I suppose a little hot glue could stick a power panel to a cardboard box, too.