Charge on my Apple Watch drains to less than 10% overnight.

If you're charging it up to 100% and then it's draining almost flat overnight, I'd say that's not normal.

On the watch, go to Settings>Battery>Battery Health>Maximum Capacity. What does it say? If it's 80% or lower, you need a new battery.

Are you using Sleep Focus at night? That will keep the screen dark most of the time.

IdrisSeabright suggestion would be a good place to start. I would run differently test scenarios to narrow down the cause.

• Charge it fully, leave it on your nightstand with it being off the charger, and check what the level at when you wake.
• When you hard reset, do you set up the watch and restore it to a backup or are you starting fresh? Try a fresh start.
• Try deleting all third party app.
• Assuming since you're wearing it at night that you want to track your sleeping habits. Are you using the stock health app to track this data or using a third-party app? If using a third-party app, try deleting that and using Health to track your sleep.
• Have you always had this issue since you've owned the watch? If not, when did it start? What did you change?
• With the watch fully charged, does it still drain to the same level in the same time interval?

You can always call Apple to have them run diagnostics on your watch as IdrisSeabright has mentioned.

iida128 wrote:

Battery health is at 96% and yes I have sleep mode on during the nights

I'd contact Apple and see if they can run diagnostics.

Genius Bar Reservation and Apple Support Options - Apple

What Watch OS is it?

Are you using a Sleep Focus Mode that allows the user to automatically change the screen brightness and Watch Face? These can be tremendous drains on the Watches battery charge?

Do you have Optimized Battery Charging enabled? This prolongs overall battery life, but your Watch may only be charging to 80% and not full, 100% charge.

Since you recently purchased it in February, take it to the Apple Store and get a replacement if the problem persists. But with the issue being so inconsistent like that, I doubt it's hardware.

Good luck.

As a test, charge your watch up, and then don't wear it overnight. What is the battery level in the morning?

Have you checked to make sure that your watch and phone are operating on the latest OS?

Iphone should be on iOS 17.5.1

WatchOS should be on 10.5

maithaihoa wrote:

Since you recently purchased it in February, take it to the Apple Store and get a replacement if the problem persists. But with the issue being so inconsistent like that, I doubt it's hardware.

Apple won't replace it under warranty if they can't find anything wrong with it.

Correct, not on an initial visit. But it’s always best to get the product into the system and their are case numbers so the Lead Genius or store manager can make the appropriate decision on replacement.

The battery will drain overnight because it is doing things like:

Monitoring Heart Rate

Tracking Sleep

Refreshing Background Apps

iida128 wrote:

Yes I called the apple today and they did run the diagnostics test and they said everything looks normal. I also took the watch to the store I bought it and they didn't give me nothing. This thing doesn't happen every night, maybe once a week or once in a two weeks. I have hard reseted it and I did not restore it from a backup. When I did that obviously all the third party apps were deleted. I use the normal health app that comes with the watch. I bought the watch in February and I started to notice this problem maybe in April or May...

Okay, if it's only happening once every week or so, that's a very different problem than it happening all the time. I probably wouldn't do anything since it's been checked out and found to be performing as designed. But, that's just me.

Something is happening on those nights that's using more battery. Tracking it down sounds like way too much trouble to me.

Jeff Donald wrote:

Correct, not on an initial visit. But it’s always best to get the product into the system and their are case numbers so the Lead Genius or store manager can make the appropriate decision on replacement.

I bow to your greater experience in this matter! ;-)