[Q] Question about chargers, cables and ROM topic

Hi,

After hours of research, I've finally bought a longer cable for charging my OPO, this one : Wooke ChargeOriginal
And to test this beautiful cable I bought a Charger Doctor too.

Here, it is why I'm disappointed ... With the Charger Doctor, I have measured the Amp many times, with different cables and different chargers and I had very strange results.
With the standard OPO cable and charger, it's most of the time charging at 0.4A. On lucky days, I can have 0.8A and sometimes ... 0.01A !
That's why I don't understand : the charger says 2.1A max and I've never reached 1A.

Then I tested with the Wooke cable : nearly the same results.

With a ASUS charger (5V - 2.1A) the maximum I've measured is 0.9A.
Other interesting fact : with an original charger (5V - 1.2A) and cable of a Nexus 4, all the results are better than the OPO's one !

So here's my question : is it possible for a custom ROM to interact with the speed of charging and do you know why I have so many differents results ?

Thanks for your answers !
And sorry for bad English !
:)