Looking for 5 cell (series) charger board for 18650 Lithium batteries

I've got a couple of old 18V cordless drills, that I'm upgrading from NiCad to 18650 lithium cells. No problem find battery management boards, but I can't find any charger controller boards that will handle more than 4 series connected cells. There are some programmable boards available that you can set the voltage on, but I'd much rather find a fixed voltage charger board. Anyone know of a source for these?

Abundant; even cheaper at pawn. In many flavors. Has what you want inside.

Thanks, but I'm only looking for the charger board. I don't know that I'd trust a used lithium battery charger, and I wouldn't pay 25.00 for a new one when I can buy new charger pcb's for under 5.00.

How about building your own?

I found this:
The listing is a bit short on details, but it's only 6 dollars, so I think I'll order one and check it out.