Backup/replacement cell phone batter?

Sure, I could look around the interwebz and search but honestly, I trust some of you techy nerds (thats a compliment) to lead me in the right direction. I have a Droid Bionic and I have about 6 months left on it. It's been a good phone, I've beat it up and used the hell out of it. But I'm at the point where I always have to have my car charger or a wall charger w/ me. If I go out I have to have it on my charger as long as I can.

For example, I'm heading to Vegas this weekend. By the end of the night, w/ minimal usage, it will drain insanely quickly. I always make sure to close out all extra windows etc....If I unplug it and don't use it, w/in 30mins it will already lose charge on the bar.

Anyway, it is what it is. Is there a good place to find a good extra/backup battery at a reasonable price? I figure I'm not the only one here whose had this issue.

Thanks in advance.

Are you sure you don't have any programs running? I know that apps can sometimes drain your battery even though you're not using them. Have you downloaded any new apps around the time the battery started draining?

You can check Amazon or eBay for extended batteries. But you're also going to need a new battery cover, and possibly a new case to fit what would now be a bulkier phone. Compare prices and reviews, and see if it'll be worth it to get a new battery for however long you decide to keep the phone.

This what you need to look for. Compare the bottom two lines. Awake, and screen on. Ideally you want them to be nearly identical. You can see that mine aren't. My phone is awake more often than the screen is on. So that means an app is running in the background. Fortunately for me I know that it's Google Now checking for Weather, Traffic (to and from work), and Scores for my teams. So this isn't an issue for me. You'd can see that the battery doesn't drain much.