Can someone solve the mystery of Samsung's charging methodology?

[AC Question]

I have a Galaxy S4 as well as a Note Pro and they both are mysterious in how they charge. I probably have 100 charger configurations, car chargers, thick 15' USB cables, short cables, data cables, USB 2.0, USB 3.0, aftermarket power supplies, Samsung labeled power supplies, etc...and they all charge these devices at different rates. I have even tried a mod from a forum where some resistors were added to the cable to indicate to the device that the full rate should be used.

All devices are capable of 2A, but some charge at such a low rate that they can't keep up with usage. Other combinations work out about even, where I don't gain or lose any power during usage, and some will gain a bit. The *only* combination that actually charges at a high rate are the chargers that came with the devices. Any other combinations charge at much much lower rates.

How does Samsung determine the device and why do they care so much? Is there any way (even with a rooted device) to tell them to default to the highest rate? I feel like I have read and soldered and bought so many types of AC adapters and cables (FYI, some of this behavior has changed with firmware updates) yet I have no definitive answer to this...

Anyone?

 

[chanchan05]

1. Quality of the cable.
2. Quality of the charging block
3. OEM supplies. Basically Samsung charging blocks have a chip that talks with a corresponding chip on the phone saying they're both original Samsung. AFAIK Samsung limits charging rates for non OEM charging units to 1amp or lower for what they claim as safety reasons. Which is understandable since the phone can't tell if you're using a poor quality 1USD block or a good Anker one.

 

[King Lerch]

They must have quite a chip/method to do this as the same charging block with a different cable will not do a full charge. It is more of a pain with Samsung as "oem" chargers are often not authentic, desipte the counterfit logo looking real.

 

[chanchan05]

They must have quite a chip/method to do this as the same charging block with a different cable will not do a full charge. It is more of a pain with Samsung as "oem" chargers are often not authentic, desipte the counterfit logo looking real.

That's where cable quality comes in. I have 2 3rd party cables. One charges at 1 amp with an OEM block, the other charges at 2 amps.

As for authentic, just get them from a reputable source. In my case there are Samsung Concept Stores in malls in my country, so I can get supplies directly from Samsung.