A not-quite-ordinary power bank that couldn't escape a few modifications.

I've mentioned a few times that I also install video surveillance systems.
So I decided to order myself an unusual power bank to help with the job.
What it's for, why I chose it, what's inside, and what can be done with it—read on.

We used to have analog cameras; now they're digital, but they all need power while being set up.
With an analog camera, I have to use a small TV, but I can power the camera from the system's main power supply over the cable that's already been run (if there is one).
I set up digital cameras using a laptop, but since all the cameras I install are powered via PoE, the port is occupied, so I have to power the camera from an external source again.
I usually use a 12 V, 7 Ah battery with a long cable and a splitter at the end, so I can power both the camera and the TV at the same time.
Anyway, when I saw this device, I thought it would be more convenient, since having a cable dangling down from a height isn't ideal.

I ordered it, and it arrived.
It came in a regular yellow envelope. The device was in a box, wrapped in a thin layer of bubble wrap.
Despite that, nothing was broken—not even the box was dented.


Inside the box were the power bank itself, a charger, a cable, and a manual.


I'll start with the power bank.
The main specifications are listed on the back.
Input voltage: 12.6 V.
Output: 10.8–12.6 V
Capacity: 1800 mAh


There's nothing special on top; the inputs and outputs are labeled.
The USB output is labeled, but this device doesn't actually have one. According to the manual, though, there's also a version that does.


One end has a power button with an LED, an output connector (which also serves as the input for the charger), and a plug covering the USB port that's not there.


The device isn't very large, in my opinion.
108 × 64 × 26 mm.
I didn't weigh it, since I don't see much point. If anyone's interested, I can weigh it.


The device is fairly easy to take apart.
First, remove the 4 screws on the bottom. Then comes the “fairly” part: the cover is also stuck down on the inside with double-sided tape.
Inside are three 18650 batteries, with protection boards mounted on top. You can also see the button, connector, and resistor for the LED.
That's it—there's nothing else inside. The batteries are the same color as in the photo (a recent review mentioned that the camera doesn't capture purple well): purple.


The batteries have an external protection board made up of several resistors and a controller IC, the DW01.


And the MOSFET ML8502A as well. I couldn't get a photo showing both the IC and the transistor, so there are two photos.


As I mentioned above, the device comes with a charger.
I've hidden the description and photos of the outside and inside behind the spoiler.

A cable was included. The connectors are standard for most devices that need 12 V: positive inside the connector, negative on the outside.
The cable is about 50 cm long.


The manual lists all the versions of this device—which, by the way, are quite numerous. See the photo for more details.


Naturally, I had to run some tests. You could even say this is the main test for devices like this.
The device wasn't fully charged, so I first connected it to my power supply for the test.
I waited for the charging current to drop. The meter showed that 625 mAh had gone into the batteries.


Next, I put together a simple test setup consisting of a constant-current regulator circuit.
The current regulator uses an LM317 IC connected in the usual configuration, along with two resistors. The current is set to 1 A (I figured a discharge rate of 0.5C would be about right).


After about 5 minutes, I measured the voltage. It had dropped quite a bit, in my opinion.
Well, as the saying goes, you count your chickens in the fall. So we waited for the discharge to finish.


The discharge lasted about an hour, a little less.
Here's why I say “about.”
The device was sitting next to me, warmed by the radiator, and I checked on it from time to time. But I didn't think it would discharge so quickly, so I missed the moment it shut off.
By my estimate, the discharge took about 58 minutes (definitely less than an hour, but more than 55 minutes).
That means a capacity of almost 1 Ah, compared with the claimed 1.8 Ah.
Sad. I was really disappointed; I thought it would do better.
To double-check, I put it on charge.


I thought I'd repeat the test after charging it, but that turned out to be unnecessary.
The most the power supply could deliver to the batteries was 1.07 Ah. There was no point in testing them any further.
By the way, I noticed that the battery voltages differed: one battery clearly had more capacity than the others.


That was the end of the testing, and I moved on to a small modification that was practically begging to be done.

Summary.
Pros.
Good packaging.
I generally liked the design itself; you could even say it's convenient.
Decent overall build quality, although the crookedly glued batteries are a bit depressing.

Cons
The battery capacity is almost half what was claimed—the biggest drawback.
No battery charge indicator.
The charger delivers less charging current than claimed, although its build quality is perfectly decent. I think the current could even be increased.

My opinion.
This device is perfectly usable, but I'm not sure whether it's worth buying. It's probably easier to build one yourself.

This device was provided free of charge by the chinabuye store for review and testing.

I hope you found my review interesting, or perhaps useful, and that it helps you make the right decision. I haven't come across any reviews of this device.