On the Wikipedia page for Nintendo 64 accessories, there is this statement about battery-free Rumble Paks:
Battery-free Rumble Paks — Late in the N64's run, a few third-party companies made Rumble Paks that, instead of requiring batteries to work, drew power from the system. Curiously, it was possible to modify an official Rumble Pak using basic soldering in order to make it powered by the console.[citation needed]
Can an official Rumble Pak be soldered to be powered by the console and not require a battery?