Change cordless to 120 volt on new 40volt saw?

[RR78]

Considering getting the new Makita 40 volt 8 1/2" sliding mitre saw.  It would only be out of my shop maybe a few times a year. Where the cordless would be a benefit.

What are my chances of getting a 120 volt to 40 volt power supply and rigging something up. Concerned maybe a chip inside battery or toll that talks to each other and stop me.

 

I dont keep my shop heated.  So not great for the battery.  So best if I can mainly run it from a outlet.