My iPhone 5 has been used for 2 years, and out of warranty. The battery is not what it used to be anymore, I think it's time to replace a new one. But I find two battery for replacement, I don't know how to select. One is one of those Diy kits (25 dollars including battery),I saw it at iFixit, and Another one is an OEM replacement battery 1440mAh for iPhone 5, only $3.99 (shipping fee not included) at a cell phone parts online shop-Hytparts store. Which is better for me to choose, you think?