Can you repressurize tennis balls after they have already lost their bounce? It is one of the most common questions among players looking for an alternative to constantly opening new cans of balls.

To understand the answer, it helps to understand why tennis balls become flat in the first place.

A pressurized tennis ball contains gas at a higher pressure than the surrounding atmosphere. Over time, gas gradually diffuses through the rubber shell. The internal pressure decreases and the ball begins to feel softer.

This means that a tennis ball can feel “old” even when the felt is still relatively intact.

A tennis ball pressurizer attempts to influence this process by exposing the ball to increased external pressure. When used over a sufficient period, a higher-pressure environment can help increase pressure inside suitable used balls.

However, repressurizing a tennis ball cannot repair physical damage. If the rubber has deteriorated, the ball is cracked or the felt is completely worn away, increasing its internal pressure will not make it equivalent to a brand-new ball.

The best results are therefore generally achieved with balls that have primarily lost pressure but remain physically usable.

With the Pressure Pod MAX, softer balls can be stored at up to 29 PSI for a higher-pressure cycle. Depending on the condition of the balls, this process may require one or more days. Once the desired playing characteristics have been reached, the balls can be stored at approximately 20–22 PSI for maintenance between sessions.

This also explains why prevention is preferable to waiting until tennis balls become extremely soft. Using a pressurizer from the beginning can help manage pressure loss before it becomes severe.

So, can flat tennis balls be repressurized? In suitable balls, pressure can potentially be increased by storing them in a sufficiently pressurized environment for enough time. But a pressurizer should not be confused with a machine that makes every damaged tennis ball completely new again.