What you see up above is the exploded battery of an HP laptop.
How will you know if it has exploded? You'll see or hear the signs if you see smoke or hear popping sounds coming from your laptop. To prevent such a thing from happening, please pay attention to your laptop's battery life. If it's battery life is now running less than an hour that's a big sign that it does need to be changed soon. Don't wait til it actually explodes and causes more damage to your laptop, causing it to be even more costly.
So if you notice your laptop's battery starting to run low at an exceedingly fast pace, please bring it in so our technicians can change that for you.