Zeus battery life and why stimulation may not last all night

If you feel that the stimulation from your Zeus becomes weaker or completely unnoticeable during the night, this is normal and nothing to worry about.

Why the sensation can fade overnight

Research shows that when using Zeus, the nerve receptors in the skin can gradually get used to the sensation of stimulation. As this happens, the feeling of stimulation can reduce or even disappear altogether.

At the start of the night, when you switch your Zeus on, you will usually feel a gentle stimulation under your chin. As the night goes on, that sensation often becomes weaker and may become completely unnoticeable.

This does not mean your Zeus has stopped working.

Your Zeus is still doing its job

Even if you cannot feel the stimulation, Zeus is still stimulating the muscles that help keep your airway open and prevent the tongue from collapsing into the back of the throat.

Zeus is designed to be worn unnoticed. Using it successfully does involve a level of trust that the device continues to work even when you are not aware of it.

Although your skin receptors adapt to the sensation, the muscle itself continues to be stimulated.

Why Zeus uses a stimulation pattern

Zeus is programmed to stimulate for 6 seconds and then pause for 4 seconds. This on and off pattern is essential.

If the muscle were stimulated continuously, it would adapt too quickly and become less responsive. Over time it could remain relaxed in the back of the throat, which would contribute to snoring.

A useful comparison is exercise. Repeating the same movement continuously without rest makes muscles less responsive and less effective. By alternating stimulation and rest, Zeus keeps the muscle responsive and gently active, helping to hold the tongue in a slightly forward position throughout the night, even if you cannot feel it.

What to do if the stimulation feels very weak or stops

If at any point you feel the stimulation is much weaker or seems to have stopped, try the following checks.

First, press firmly on the device electrodes where they contact your skin. If the device has shifted away from the Hydrogel Pad, the stimulation may not be conducting properly. Repositioning the device can often restore the sensation.

If you are having trouble keeping your Zeus or Hydrogel Pad in place, please refer to our support article and video for placement tips.

If you still cannot feel anything, briefly press the plus and minus buttons together as if you were turning the device on.

If the LED flashes red once and then green, the device is active and working as intended.

If the LED flashes red only, the battery has run out and your Zeus needs charging.

Adjusting the stimulation level

If your device is flashing green and you would prefer to feel the stimulation more strongly, you can increase the stimulation setting.

The higher the setting, the more likely you are to feel the stimulation for longer into the night.

If you try to adjust the level after the 20 minute sleep mode has started, the device will not respond. To make changes, press the plus and minus buttons together first to enter adjustment mode. This design helps prevent accidental changes while you are asleep.

When adjusting the level, wait for the green flashes to finish before increasing or decreasing to the next setting.

Once you have chosen your new level, if there is no further interaction for 90 seconds, Zeus will re enter its 20 minute sleep mode and then begin stimulating at the new level.

Starting the night at a higher setting

If you find the stimulation comfortable, another option is to begin the night on a slightly higher stimulation level. This can reduce the chance of the sensation becoming completely unnoticeable later on, although it is still normal for it to weaken as the hours pass.

Understanding the LED light

The LED light switches off as soon as your device enters sleep mode and stays off for the rest of the night so it does not disturb you.

If you do not see the LED flashing, this does not mean your Zeus is off.

As soon as you press the buttons together, the LED will activate so you can check status or adjust the level. After setting a new level and leaving the buttons untouched for 90 seconds, the device will return to sleep mode, the LED will switch off again, and stimulation will begin shortly after.

Helpful tips for best performance

Ensure your Zeus is fully charged before use. This helps maintain maximum stimulation throughout the night.

Use a new Hydrogel Pad every night.

Reseal the Hydrogel Pad packet after opening to maintain moisture and freshness, which helps maximise stimulation sensation.

Zeus battery life is tested to last up to 16 hours on the highest stimulation setting, so it is very unlikely that the battery is running out during normal overnight use.

How to tell if Zeus is working effectively

If you want reassurance that Zeus is doing its job, there are several ways to assess its effectiveness.

Many users notice they feel more refreshed and better rested during the day.

If you share your sleeping space with a partner or family member, they may notice improvements in your snoring.

Some users choose to track their snoring using phone apps such as Sleep Cycle which record snoring volume and duration. This can help you see whether results remain consistent throughout the night.

If you have any concerns that your snoring is returning when you cannot feel the stimulation, please email our support team. We are always happy to fully test and inspect your Zeus device to ensure it is working exactly as it should.