I have an 18V Milwaukee cordless impact wrench and one of the batteries just **** the bed, can I relace it with a Milwaukee 28V Lithium Iron battery? If so, guess I also need the 28V Lithium Iron battery charger?

If yes to the above, it will probably get pretty costly so I would probably be better off just getting a new 18V battery.

 

According to this page they have a universal charger. However it says nothing about mixing batteries. Why not contact them.
http://www.milwaukeetool.com/webapp/..._192145_192137

 

I will contact them on Monday, just curious if anybody else has been there done that

 

I doubt it would work. I don't have an 18v, but my 28v impact driver and my 14.4v drill have different slides for the batteries. I suspect that the slides are different for the 18v and the 28v also.

 

I think the slides are the same since they have a charger that charges both the 18V and the 28V.

 

I have the 28v charger, and tools. I'm not sure if the batteries are interchangeable on the tools, but my charger will accept both 18 and 28v.

 

I suspect that if you put a 28v battery on an 18v tool (if it can even be done), it will run really fast....for a short time!

 

As Bull states and likely will burn the wiring in the armature.

 

That's what I thought and just confirmed with Milwaukee. They do have new 18v lithiom-ion batteries to replace the NiCd batteries.