Thought I'd make a portable battery charger, as a 'just for fun project', using 18v 2.4 Ah Li-ion tool batteries with an adaptor plug. The batteries (with charger) were selling cheaply at one of our big Hardware centers. NZ $30 was a bargain so I bought 3 while the special was on. I have a number of old NiCad powered drills (oldest is an original Ryobi 7.4V cordless from the 80s) converted to use LiPos, (3 -7.4v and 2 12v -one converted for car use) I also have 2 older 18v drills but there are no LiPos to suit the voltage (could us a 4s at 16v, but that's a bit low) The new 18v Li-ion batteries are ideal for the conversion.

I made a board up to mount the charger, battery, and an 18v+ to 15v voltage reducer (from Ali Expr) to suit the charger input voltage (max 18v, - wanted to reduce it slightly) I can plug the 18v drills straight into the battery extension, or plug that into the XT60 connector on the board, to use the charger.

You might ask,"why not just use the car battery/lighter socket for the charger" - examples might be A, - you don't charge LiPos inside cars, B, - you don't have to leave the bonnet up in your car (maybe risking chopping your charger lead - or have to leave your keys in the ignition). and C,- You can't always get your car close to your pond if you might want to charge/ touch up a battery or drill a hole etc.(and keep an eye on your car)

Works very well, and with the 3 Li-ion batteries charged at home, I can have 7 hrs of charging. I can even plug in a 12v light if needed.

JB