I found the other day that the watch will not charge if not powered on. Had drained to 0 and powered down then sat on the charger for a day while off. Went to turn it on and it was still at 0%. Charged fine once it got powered on. 

OK quick update, I managed a full 6 days with 18% left before charging and this was with a few tracked activities thrown in. Watch was charged last night and put back on before bed. It's only used 6% so it does look like the drain is no longer happening…

It did actually, .2% less an hour, but then, just like the post two above says, I got an update a few days ago and now it is much much worse. I can barely get two days of charge. I just charged last night, in fact, and now have 65%.

Shut it down and restart it - then charge it to 100% - mine was at 80% on Monday and is at 38% today after 32 miles of running.  Granted I also set it to turn the screen off unless I tap it - but initially the battery charge percentage was horrible and…

Mine is doing exactly same, even on 100% charge, just over 3 years old, built in obsolescence Garmin?

That is great if we can get 8 days. I want to get to charging once a week

Same issue. Battery has to be charged every single night. Why does no one from Garmin reply. Pathetic.

I too have a crazy drain on my venu2. From a full charge it lasts less than 24 hours. When it gets near to the 50% mark it powers off, and shows battery at 0% needing a charge. Ive contacted support and hey presto its a battery issue, and they will happily…

You are lucky, so don't complain. I was getting the same before the 8.30 update, even though my watch is 4-yo. Now I'm charging it once or even twice a day, like I have an effing Apple Watch. I might as well buy one, after all I'm already used to daily…