I had this for my 3XL and it works great to actually fast charge the phone. nIve noticed that my 4XL and my wife's 4 no longer charge rapidly. I know the 4 requires EPP and can't find anything saying the boostup has it, but a Google search turns up nothing about people having issues.
ive also figured out that once my 4xl reaches 100% on the boostup, it stops charging and doesn't start again. I haven't tested that with my wife's 4 yet, and haven't figured out if it exhibits the same behavior on other wireless chargers.
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