If you’ve been shooting with a flash for a while, I’m sure you had some battery problem or another at least once. Like when one of four batteries goes bad and quickly discharges the other three. Or when it’s cold and the batteries don’t hold their charge so well anymore. Wouldn’t it be nice if you could have a more reliable source of power? One that virtually lasts for ever (well, not forever, but for a darn long time). This is probably on the wish list of anyone who is shooting off shoe and don’t care much about weight, but do care about recycling time and number of pops that can be squeezed in a session.
Konstantin Sirotkin describes how to make a Flash mod that will allow you to connect your flash to an external power source.
Yes this is an external power source, no mater how bomb-like it looks.