I have several rigid cordless tools that use the ni-cad batteries. These batteries have failed and now the only way to replace them is time consuming and a hassle because the ni-cad are no longer available in stores - only the new li-on batteries. Can the new li-on batteries be used with the old rigid tools that used ni-cad batteries without causing a problem? The old ni-cad battery number is 130254007.
only issue is that you will need a charger if your charger is not a multi chemistry unit.
Ridgid still makes new NI-CD batteries. I am unsure how to buy them except on Ebay, (EDIT CPOProTools.com) but the way to tell how old the "new" batteries on eBay is to ask for the CS number on the bottom, i.e. CS1029. 10=2010, 29=29th week(of 52)
Ridgid Batteries | Power Tool Batteries | CPO Ridgid
Also your local authorized repair shop can order them. Everything except for LI-PO batteries are cheaper thru them.
18v NI-CD 1.9= $56, 2.5=$66
18V Li-ion buy at HD or eBay