Apple Watch 7 not charging to 100

RCM63 wrote:

I have a new watch version 7 that does not charge to 100%. I am using a new charger and leaving it overnight. Is this a defect?

Optimized battery charging helps conserve the battery lifetime, but it sometimes means that the battery won't charge past 75%-80%. You can override that by selecting "charge to full." Details are provided here:

About Optimized Battery Charging on Apple Watch - Apple Support

RCM63 wrote:

i have a new watch 7 that does not charge to 100% with a new apple charger

That watch was discontinued three years ago. It may not be totally new, or the battery may have aged wherever it was stored.

Having said that Steve626 is correct.