I have used BeWeather on two different models, 9000 and 9800 without a real problem. My phone updates every 2 hours except for wee hours overnight. No other special settings are in place. Battery life on both phones was not affected enough to matter.
If you still have trouble try removing the app, check battery life, and reinstall the app. Sometimes that makes a difference.
Even before removing the app if you have not tried a battery pull do so now. Repeat after reinstalling if you have to remove the app.
try setting updates for every hour or two. should help out. and if there is a certain time in the day that you dont want to know the weather use the setting to stop updates during that time frame.
I have mine set to GPS location with updates every 15 minutes, alerts are pushed. Only time BW impacts my battery is when it can't get a lock on GPS and keeps trying to update.
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