I got a Zagg Sparq in December. It would charge my Droid and 2 different Motorola bluetooth headsets fine, but it would discharge from 100% to 0% in about 2 weeks. This should not happen with a lithium polymer battery. Zagg was good enough to follow up with all the Sparq buyers to see if they were having any problems and I told them about the discharge problem. They sent me a prepaid return envelope about 3 months later and then sent me a new Sparq and a set of Zaggbuds as a gift to make up for the Sparq problems. Excellent service from Zagg. I even got the red and black ones since they ran out of the blue and orange ones they were sending out.
My new Sparq 2.0 arrived last Tuesday. I started the charge before noon that day and allowed it to charge for about 9 ½ hours. The first charge is supposed to be at least 9 hours. After charging, it was at 100% (4 lights). I didn't use it to charge my Droid and would check the charge amount every night. Three nights after the completed charge, the charge showed 75% (3 lights) and today (9 days later) it showed 50% (2 lights). It appears that the discharge problem still exists, unless additional charges will improve that. Additional charges did not improve the self discharge on the original Sparq.
I plugged in my Droid about an hour ago, which was at 30%, and it charged the Droid to 100%. The Sparq still shows 50% charge. I will allow it to discharge some more and then recharge it. It appears that there is still an electrical leakage problem, unless additional full charges improve this. At least I got a pretty good pair of ear buds. They are not as good as my Etymotic HF5, but they are fine for casual listening and they are comfortable.