Rechargeable Lithium Battery Link
Since most rechargeable lithium batteries are 3.7 volts or multiples series thereof I found this article to be useful https://learn.adafruit.com/li-ion-and-lipoly-batteries/voltages
Forum Discussion
You are better off buying complete NEW battery packs.
You can get new 18V packs for your Ryobi for about $34 each which is a bargain compared to a lithium fire..
RYOBI BATTERY PACKS
That price is for NiCd battery packs. The Li ones in the link are two for $125, same as the local Home Depot. It also has the $99 for drill, driver and two batteries package. It seems the tools are free and the batteries overpriced.
Would NiCd batteries be the way to go because the lithium cells will inevitably develop a tenth volt differential among the cells and die? I know people who have used a NiCd driver battery for a decade.
Thanks for the link to Li cells.
Would it be safe to attempt eliminating the differential between cells by slightly charging the lowest voltage cell a wee bit - say 50 mA for ten seconds?
