Review: DX.com's 5A USB Charger

 

5V/5A (25W) USB Charger

Here is product that I bought from DX.com created by ZnDIY-BRY.  Link

Recently, we have lots of devices in our home that uses USB chargers. But why did I build one?

1. I know for a fact that there are USB chargers that have high current output. But some of them have very bad regulation. I bought a cheap USB charger for my mom, and it destroyed her Samsung Galaxy S3. I checked the charger and saw the voltage rise up to 5.6V at 1A, but I don't know the actual voltage when the scenario happened. We also bought from an unknown manufacturer and the voltage rises up randomly when the current draw is greater than 1A.
2. Last year, I bought one product from ZnDiy-BRY, a 2 port USB charger 3A. This is a very good product. I use it in my office to charger my Galaxy Tab and Samsung Galaxy Note. Given this company's very good reputation, I bought their 5A, 4port USB charger.
3. DIY and building is fun!

After I received the item, I did a very simple 3D printed bottom cover just enough to avoid the bottom part of the PCB to be in contact with our house floor.

Since this is a 25W (5V/5A) device, I chose a DC supply of 12V, 3A (36W). This is to give enough margin for the efficiency of the USB charger and the DC supply

In this test, I placed 4 devices that are in charging state - A Samsung Galaxy Note, Two Samsung Note 2, and a Sony Xperia C5. All of them are in charging state and none of them are in fully charged state. The voltage is at 4.93V on this test (my USB doctor have some issues, but if I use a multimeter, it is exactly 5V). Then, I touched the heatsink and I am surprise that there's not much heating at all.

In summary, I am very happy with this device. It passed my expectations. Now I can keep all our 220V to 5V chargers inside a cabinet and just use this superb 5A charger..