Sometimes you charge an attack, then end up in a location where charge attacks are completely useless. It would be great if we could cancel charged attacks after charging, since with some weapons you're slowed while charging/charged, which can be dangerous even when the charge isn't useful (for example, there could be environmental hazards like spike traps), and just using the charge can be dangerous as well (especially with weapons on the Autogun or Troika lines).
Charge attacks are a risk/reward choice, the best you can do is move to a position that will minimize damage you take when you release the charge or learn how to avoid those situations.