Re: SoundSport Wireless battery drain
I had the same issue a few months back and contacted customer service.
Bottom line: they replaced the earphones (they were still under warranty).
One thing that support told me to absolutely avoid is to recharge the earphones using a power adapter. The only way in which the Soundsports should be recharged is via the included USB cable connected to a PC.
Since I received the replacement earphones I always recharged them that way and the battery drain issue has gone (I've now used them for the same amount of time since purchase of the first earphone instance before the issue manifested).
Unfortunately I can't tell if what worked for me was the replacement of a defective item or
adopting the recommended way of recharging.
My two cents.