I have bought Sound Core Mini recently from Amazon Spain. Really, it very good sound speaker with premium look.
However I have noticed after first full charge that it takes only less than 5 hours and I have to recharge the sound speaker again.
Anker claims in Amazon that the one charge lasts for 15 hours! I do not know then, I have a damaged battery or because this is the first charge?
It depends of course the loudness you run the speaker. 
And the battery has to “learn”.
This means after a view charges it may alter.
Hi @arh26884,
As @fhassm noted, the volume and function will affect the battery life, but 5 hours does seems short. It may take a few recharge cycles until the battery is “broken in,” but if it doesn’t improve, feel free to reach out to support@anker.com.
Thanks a lot for all, I will try some recharge cycles
@TechnicallyWell @fhassm Thanks for the reply. @arh26884 Please know the power indicator on the speaker should be off when fully charged. Normally, it will take 3 hours at 5V/1A to fully charge the speaker. If you tested it with the same battery life, please contact us via support@anker.com. We are happy to help you with the exchange. Thanks