Power box from Li-ion batteries

[olderdan]

Since retirement my 18 volt ni-cad power tool batteries have expired from lack of use, as I still have 9 power tools I have upgraded to 4 Ah lithium. To get more use from these new batteries I thought a power box might be useful to use with my home made rotary tool and for use as a nickel plating current supply as voltage is easily set from 3 to 18V.
I used a dead radio as a socket mount but could have made something similar from wood. Nothing special inside just a cheap PWM board and a few bits I had in stock.
Since making it I have realised how useful it is to be able to work outside with better lighting than in the shop.