Galaxy Watch8 Classic

I second the Garmin if you have iPhone, but can be pricey. If Samsung, the Ultra. The 2024 model is a deal, but they all work well. I'm currently using the Ultra 24, GW8 and GW8 Classic.

The ultra has the absolute best battery, but the galaxy watch 8 classic gets relatively close, if you want something lighter and cheaper. Four to five days is almost impossible though unless you absolutely baby it. No wear os watch really has great battery life, though, at least not the ones that exclusively run wear os with no lighter os to fall back on. Wear os is very powerful for a smartwatch, but that makes it heavier to run too

If you have tattoos where a watch would sit then I'd avoid Samsung. I used to have an apple watch ultra 2 and the sensors on that were great over my tattoos. I changed to android and got a Galaxy watch 8 classic and it wouldn't detect anything at all. I've now got a pixel watch 3 and it works great.

If you’re looking for WearOS watches (since this is the Android Wear subreddit), there aren’t many options: Samsung Galaxy Watch (the only ones with ECG), Pixel Watch, and OnePlus Watch. There’s also Mobvoi and Xiaomi, but their last model came out two years ago, so it seems like they’ve given up. I have the latest Galaxy Watch8 Classic, and it looks good. It offers a 24-hour battery life with all features turned on, just like a phone. There’s also an LTE version, so you can leave your phone behind from time to time.

2 days on average Source: I have it