This guide is going to concentrate on the new 18 volt Nano Lithium Ion Dewalt cordless system.

The Dewalt 18 volt cordless tool line is the most popular cordless tools in the USA hands down.

Lithium ion is becoming more and more popular because the batteries will last longer, accept more charging cycles and they are much lighter for the same power.

Dewalt is no exception but has done a great service to all existing 18 volt power tool owners, because the new 18 volt Nano Batteries work in existing Dewalt 18 volt tools designed for NiCd type batteries.

They work perfectly! The only existing tools that the Nano batteries will NOT work with is all prior chargers, Radios (they contain battery chargers), and Vacuums (they just dont fit in there).

The other 40+ Dewalt existing tools work perfectly. The fit looks a little odd though, because the Nano batteries are much smaller. The placement of the clips that hold the batteries in place and the length and size of the connecting part of the batter is perfect but the older style tools have the clamshells made larger to provide the custom fit for the NiCd batteries.

So, dont hesitate to buy that new set of batteries just make sure you get a new Yellow top version battery charger with them, the new batteries will not fit in the older chargers.

Do not modify the new batteries to fit older chargers!!! the design is intentional and doing so would create a serious fire and or explostion hazard!

Lithium ion batteries are charged differently and cannot accept a charge from older style chargers.

Additionally, The new Nano Tools ACCEPT the NiCd batteries!!! And the new Yellow top charger will charge the NiCd batteries! Dewalt PERFECTION! 

I hope this was helpful, Thanks, Bishop Supply, Auction_4_Fun