From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Hi-Tension is a supportive technique used by many fighters. The user intensifies with enhanced power, making their physical attacks more powerful for a limited time, fills 2 of their Ki Gauges, and allows the ability to charge up to happen faster until the user attacks with a rush attack or energy blast attack.
It later appeared in Dragon Ball: Raging Blast and allows the user to go to MAX Power. If MAX Power ends, the user's entire Ki bar will be consumed. Since the advantages of this move are so overrated, only a few characters can use it. MAX Power is called Hi-Tension in Raging Blast. In Hi-Tension, you can pull off an Ultimate Blast and any other normal attack. It does, however, still consume Ki to use super attacks, signature attacks, and all other Ki-consuming attacks whilst in Hi-Tension.