As of today, all of the NES and Game Boy Mega Man games have received a patch that makes weapon energy refill upon losing a life.
The goal of these patches are to make the game less frustrating (especially during final stages, where some weapons are required to pass the level), but also to create consistency with the later Mega Man/X games for Playstation 1 and PSP.
If you got sick of running out of Magnet Beam in Mega Man 1, or Rush Jet in Mega Man 3, or even the Carrier from Wily’s Revenge, be sure to try out these patches! They may save your sanity during these heinous final stages!
Get the patches here:


https://www.romhacking.net/community/5312/