USB battery box 2x18650 (Aili 168)




The battery box is marked with aili168 on the bottom, but was not sold with that name. I got it from "frank-studio" with the name "portable-type 5V 1A Mobile Power Supply USB Battery Charger 18650 Box".
The specifications are:

• Battery replaceable
• Intelligent charging with indicator to show the charging status
• Output current-limiting protection to avoid damage when over load
• Can charge most cell phones as well as iPhone and other Apple products
• Activating the substitute batteries for outdoor use
• Charging Input: 5V / 1A
• Output: 5V / 1A
• Color: black, white
• Material: Plastic
• Batteries: 1 to 2pcs of 18650 lithium batteries (not included)
• Easy to open and close the charger box, just need press to one side, and don't need any screw.

How does it look



I got it in a envelope with bubble wrap around the box, it did only include the box, there was no cables or batteries included.



All connectors and some indicators are placed at the end of the box.

• Small led: Will be red when charging and green when full.
• Mini usb: Charge input, connecting power here will also reconnect the battery.
• Large led: Will be white when the top button is pressed, can be used as a small flashlight when connecting cables.
• Large usb: USB power/charge output.

On one side of the box is a small hole, pressing a needle into this hole is used to reconnect the battery. This must be done after replacing batteries.
In my opinion this hole is too small, I do not carry a needle and this makes it difficult to reconnect the batteries (When I am finished with this review I will enlarge the hole).



On top of the box is a square button with transparent plastic around. The button is used to enable the output and when pressed the white led and battery indicator leds around the button is on. The output will automatic turn off when the load is removed.
Behind the transparent plastic is four leds.

• Small red: Output is turned on. This led stays on as long as the output is on.
• Large red: Battery voltage is below 3.8 volt
• Large green: Battery voltage is below 4.1 volt
• Large blue: Battery voltage is above 4.1 volt

Slide the top back and it can be removed, giving access to the batteries and electronic.



The box with two 3100mAh unprotected Panasonic cells.
It can work with up to 69 mm long batteries.





A closer look at the electronic (Click for larger pictures).



Measurements

• Minimum load to turn on and stay on is about 65mA
• In battery disconnected state the box uses about 50uA from the battery.
• With battery connected and no load the box uses about 0.7mA (This is about 1 year with a full load of 3100mAh batteries).
• The box will disconnect the batteries when the voltage is 2.9 volt (Measured with no load).
• Using Apple 1A coding

The first test is a load sweep test to get an idea about the performance. The box can deliverer about 0.9A for time this test takes. Note: The spike at the start was due to automatic turnoff.



First test is done with a 6 ohm load (0.83A), the box can handle that for more than an hour, but then the voltage starts dropping.
The low voltage turnoff is good, it turns completely off at about 2.9 volt.



Reducing the load to 7 ohm (0.71A) looks much better, here the output voltage will stay high enough, until the battery is empty.
Looking at the current curve, it looks like the circuit is limited to drawing 1.5A from the batteries and if that is not enough the output voltage will drop.



Reducing the current to 0.5A (10 ohm), shows a good output voltage and good efficiency of about 80%.



Using a single 3400mAh battery.



Using a single 3100mAh battery.



Using a single 2600mAh battery. The lower capacity will give shorter runtime.



There is a lot of noise in the output from this box (525mV).



Even at 0.5A the output is full of noise (388mV).



The box will turn off automatically if the load is removed. This might make it turn off with some equipment connected (Like when a phone is fully charged).



Charging two batteries in this box is not very fast, it takes about 9 hours. During charge is uses up to 1A, but most of the time it will charge with a lower current.
The charge curve is not CC/CV, but except for time, it is just as good.



A single battery is charged in nearly half the time.



A 2600mAh battery is slightly faster to charge.



Conclusion

This box is a very handy size for a USB power box and it is easy to change batteries in, but the very small hole to reconnect the batteries is a problem.
The noise is way to high and I would have liked a faster charging. The over discharge protection is good and the box can be used with unprotected batteries.



Notes

Read more about how I test USB power supplies and chargers