regarding the safety of replacement battery

hi ..my name jacob.my i phone 4s has now just hardly 3 hrs life.I wanna to change its battery as you explained in your website.however I am bit scared as everybody told me that the Apple does not produce it`s original replacement battery ,putting these kind of non branded companies battery will cause damage phone`s internal circuits and also may be these batteries will burst or leaks [bulge out]easily.So I am really confused.could you please suggest any solution or can u say what is the best companies`s battery for this work.

I eagerly looking for your prompt reply.

than k you