I have 2 different powerbanks, both have 10000 mAh and both are rated for 5V 2A power input.
I have noticed that they draw a different amount of current despite using the exact same charger (5V 3A), same port and the exact same USB-B-Micro cable.
One of them draws 1.6A while the other one draws only 0.7A. Same results on further retries.
How can there be such a difference?
Is the flawed latter charging IC (0.7A) too paranoid of overdrawing current?
- The slower powerbank that charges at 0.7A is newer and has been used much lesser than the faster powerbank so far.
- Both powerbanks only charge faster when compromising cable length. The limit in each case is 2A as the specification said, which can only be reached on slower powerbank when using a cable shorter than 10cm/4 inches. However, one of the powerbanks charges significantly slower with the same cable length, in fact the exact same cable. 0.7A with the exact same cable as the faster powerbank at 1.6A.
- Both of the powerbanks were at around 25% of charging state during the test. This means that their internal terminal voltage of the Lithium-Ion cells is rather low but very similar.
- According to imprint, both powerbanks use Lithium Ion, not Lithium Polymer.
- Again: Both are tested using the exact same cable.