Ok so i have an Verizon iPhone 4s 32gb that i got from my friend. He gave it to me because he got the 5. Now i plan to fix it myself(screen is broken) but now ive run into a problem. It only charges up to ~20% Now this is out of warranty and im asking for your opinion so i can save money. Do you think this is a problem with the dock connector or the battery? I'd love to know what you guys think it is so i dont have to buy both parts and then hope it works.