Talentcell 12V Lithium ion Battery Pack, 11.1V/9000mAh...

Most Helpful Review

"TL;DR If you are looking for a reasonably cheap Li-ion battery pack for light duty work then this will probably work fine, just don't trust the manufacturers ratings for anything even approaching critical.First off the lithium cells are of decent quality (LG brand) at a rated capacity of 2600mAh/cell, however, that is where our first problem comes into play. There are nine cells inside for a total of 86.58Wh (9.62Wh/cell) worth of energy, making for a battery that has only 87% of what its rated for in the description, if you then de-rate a further 80% for maximum battery health that comes to only ~70Wh (or just 70% of what was advertised), this is even more of a problem given that the cost per kWh is $565 ($48.99 / (86.58Wh / 1000), for comparison high quality Panasonic cells can be found at prices of only $265/kWh or less in volume. In short, not only are they claiming more capacity than is actually available (even if you are highly optimistic) but they are charging prices far exceeding what similar battery cells would cost even on the consumer sites like dx.com or Alibaba. Basically the same kind of slim-shady practices that all China-discount manufacturers try to pull. Good buy if you are in the market for only 70Wh and don't mind paying extra."