Bests & Worsts Reviews from Amazon

I just purchased one from Amazon one week ago and just returned it today at my own cost even though the product itself was defaulted. It cannot be fully charged at all for more than 24 hours of charging. The seller replied back to my question of not being fully charged and asked me to contact the NOCO support. I contacted the NOCO support and did what they asked me to do. They asked me to try any smart phone micro USB cable instead of the provided one. Nothing worked. The NOCO support finally asked me to return the product to the seller. I was curious about this product so bought the same one at Autozone today. Guess what??? I have started charging the unit using the provided micro USB cable since I bought this afternoon. It is still charging at 25% level after more than 8 hours. It is way worse than my first unit. My first unit keeps charging between 75% and 100%. My second unit keeps charging below 25%. I will probably return this tomorrow. I am not sure whether I am not that lucky enough to have a decent one or this product has a problem with charging.