My problem is the watch only sends a battery warning at 10%. I need to know earlier than that at least 25%. Too many times I got to the gym only to find my watch is at 10% and I can't charge it. I looked over settings there does not seem a way to change it.
You need a third party app for that. If you want an audible alert, you could use Juice Watch, Remote Battery, or Phone Buddy has the feature as well, although that is not its main function.