Bests & Worsts Reviews from Amazon

My wife, my son and I each have Galaxy S4 phones which are approaching two years old. When we got them, they were blindingly fast and would run, in fairly heavy use, for two days before requiring a recharge. Over time, though, I noticed mine seemed to be slowing down and required more frequent charging, often giving me a low-battery alarm in far less than a day. My wife and son noticed the same with theirs. I purchased external charging batteries, which helped, and uninstalled apps we didn't absolutely need, which had almost no effect either on speed or battery life. As a last resort before replacing the phones, I ordered three RAVPower 2600mah replacement batteries, chiefly because so many of the "genuine Samsung" replacement batteries were being identified as counterfeits. The first day we saw no improvement, but the instructions advised that several charge-discharge cycles were needed to obtain the full capacity of the batteries, and that is exactly what we noticed. By the third day we were already getting full-day performance, and after a week our phones were once again working for two full days before a recharge was needed. We were also pleased to find that the phones seemed to have recovered their original speed and responsiveness; I suspect the original batteries were unable to provide the current needed for all phone functions. (We've also noticed our phones now get good voice and data connections in areas which previously were unreliable or unusable, but this may relate more to major system upgrades our carrier has made in the area than to the new batteries.) I wholeheartedly recommend the RAVPower batteries, especially if you are considering replacing your expensive phone for the sort of performance issues we were experiencing.