Galaxy S3 cell standby is eating my battery My battery on my new S3 seems to be being eaten up by the cell standby using more than 50%. 
I appear to get a decent signal on the phone. Does anyone have any idea why this figure would be so high?
That is terrible! Drains to 50% only in stanby!

Maybe the apps are not really shut off. You can use the free apps - JuiceDefender to save your power. Packed with smart functions, it automatically and transparently manages the most battery draining components, like 3G/4G connectivity and WiFi.

Or you may need to have a external battery to backup. This one sugegsted:

Small and portable design, Powerful and giant inside. Will be helpful!