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.

[Tuomas]

That's usefull idea. I have many extra batteries laying without use. Thanks!

[Frank S]

I have several dead 18v power tools dumped in a box somewhere. At one time I thought about getting a transformer and wiring in a bridge rectifier them mounting that in one of the battery casings but have never gotten around to it mostly because even though they would be corded they would still have the bulk of the battery pack on them. Another thought was to make a stationary 18v DC power supply then cut away all of the extra plastic from the power tool and install a round pin or a twist lock socket in the handle making them more useful, for me at least. even though I have owned a lot of battery powered tools I have yest to find one that I really liked.
I like corded tools better I guess.
And that is one thing I like about your box even though it is still using batteries the tool becomes corded

[DIYer]

Thanks olderdan! We've added your Power Box to our Electrical category,
as well as to your builder page: olderdan's Homemade Tools. Your receipt:

Power Box by olderdan

tags: battery, power supply

[Don42]

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.

Say more about the PWM board, please. Schematic? Source?

[olderdan]

Hi Don, there is not much to say about the pulse width modulator board, there are hundreds for sale on Ebay very cheaply, just make sure you choose one for the amps rating you need. Connections are clearly marked.

Regards
Olderdan

[rebuilder1954]

Thanks! that's a good use of those two items. i have a couple of the PWM boards lying around, i think i will go give that a whirl.