The cover makes the device almost 3 times the original thickness. It has a good grip though so that helps. I could go about 2 days on one charge; before I could barely make it to the end of the day.It does what it's supposed to do but it really makes the phone ugly. Seildo has a 3000mah that has a better cover design.I have a Samsung Galaxy S but it's from AT&T and called the Captivate. I ordered this battery but it wouldn't fit. Mugen was great about exchanging it for the correct battery that does fit.Yes, it makes the phone thicker but instead of running out of battery in the middle of the afternoon I get almost two full days from a charge. Small price to pay for adding to the size of the phone.The bad news is that Amazon does not carry the right battery for the Captivate. Here's the Amazon link This battery is double the capacity of the standard slim that came with the phone new. AND it lasts twice as long. I needed more battery to run a GOLF GPS program. This is the greatest battery availableWhy does this battery say that its for the Samsung Galaxy S phone when the listing says its for the HTC Google Nexus One????? Hmmmmm ..... they may want to correct that. Its bad enough that they have 2 different pictures for the battery shown.