Update: It appears that there may be problems with endurance of the batteries used within this power bank. As a result, I can not recommend its purchase anymore.
UPDATE 2: Further investigation of the endurance problem confirms rapid degradation in cell capacity.
It seems like there isn’t many places online which take a critical look at the performance of USB power banks. As a result, I get many people asking me – “which power bank should I buy?”. It’s not an easy question to answer, because I usually only have a limited number of products on hand that I’ve purchased for testing.
Today, we’ll be looking at the Orzly Portable Power Bank (Black) from MobileZap, currently selling at AU$30.49 plus postage, with thanks to MobileZap for providing the unit for testing and review.
This unit is Orzly branded, and claims to be 4050mAh. This power bank is different from others, its main feature is that it is a “slim”, phone-sized unit which is designed to be easy to carry around. It comes in a nice colour-print cardboard box with a window for the product to show through.
Included is the power bank unit itself, a microUSB charging lead (no data pin connections) and a quick start manual. The manual itself is a little questionable – it says it’s compatible with products with a standard 3.6/3.7 voltage, but that’s not what it is at all. It’s compatible with all products which use USB 5v charging, up to 1A current.
The power bank itself is like an iPod with an almost mirror shiny back which is accented with engraved lines and markings. It claims to have a 1A input and 1A output. It also claims to be a Li-ion battery, but given it’s shape, it’s likely to be a Li-poly, which is actually a little bit safer.
The front of the unit features a very slim USB connection port, and a very recessed microUSB charge port. The top features a capacitive touch button to check the capacity.
The power bank has four LEDs to indicate capacity, which remain off even during charging. The charging starts automatically upon connection of the load – you don’t need to explicitly turn this power bank on and off, which makes it foolproof.
The unit was fairly well built and doesn’t feature any external screws that you can see. Instead, it is “clipped” together, so by carefully prying at the seams (don’t puncture the battery!), you can pull it apart to reveal its insides.
From this side, we can see the battery has a printed code of TYS13K09B 655885 005954 which doesn’t appear to be meaningful. It is printed on a large li-poly pouch battery of a single cell. The tabs are soldered to the red wires which connect it to the power conversion PCB.
On the PCB, it looks like there’s a microcontroller that co-ordinates the operation of the power-bank, but with the numbers scrubbed out. The chip marked 4057 appears to be responsible for the battery charge, and the one marked DW01AO may be responsible for the battery protection along with the FS8205A which is a MOSFET used to disconnect the battery. I have no idea what the chip marked P156 does, however.
There is no evidence of thermal or fixed current fuses anywhere, which seems to be a common theme amongst Chinese-made power-banks. They’re a good level of secondary protection which doesn’t seem to be implemented.
The connector itself is very special, to keep the form factor thin. It looks like they used some glue to help secure the connector to the board and provide additional support.
The battery itself is adhered to the top case, which is not unusual. If you find your battery rattling around, a slight push ought to solve it. The battery is marked with TMB655885PLT/405 3.7V140108007186. This points to the manufacturer as likely being ZhongShan Tianmao Battery Co. Ltd (zstmb). Unfortunately, no information about this particular battery was available on their site.
The capacitive switch is seen on the rear of the PCB. The PCB is dated 15th June 2013, and is marked WJD060_V1.4_5V/1A. This points to the actual power bank manufacturer being Shenzhen WeiJiaDa Electronics Co. Ltd (which markets their products under the brand iwoipower). In fact, their site has the model WJD060 stated as Single USB HTC power bank, claiming 4000mAh (rather than 4050mAh, but the difference is tiny anyway).
I guess that’s everything you might have wanted to know about this particular model.
As we know from experience (just take a look at some of the other power bank category articles on the website) that not all power banks are made equal. In fact, some of them miss their stated capacity by a long way. As a result, I’ve run performance tests using a 10-ohm and 5-ohm resistive load to simulate an “approximate” 500mA and 1A load to determine the true capacity via recording voltage and current pairs around once a second (80.8 times per minute, to be exact).
The test equipment involved is a highly accurate Keithley Model 2110 5.5 digit digital multimeter with computer control, and as a result, we can get results which are highly consistent and repeatable.
The results are as follows:
Orzly Slim 4050mAh Power Bank Test Run Capacity Run Capacity 500mA-1 3793.753177mAh 1A-1 3590.607963mAh 500mA-2 3791.776170mAh 1A-1 3593.139183mAh 500mA-3 3790.766124mAh 1A-1 3596.570975mAh 500mA-4 3784.069303mAh 1A-1 3595.033437mAh 500mA-5 3778.923580mAh 1A-1 3579.705526mAh Range 14.82959687mAh Range 16.86544949mAh Mean 3787.857671mAh Mean 3591.011417mAh StDev 6.179410059mAh StDev 6.700721401mAh Efficiency 93.5273499% Efficiency 88.66694857%
As we can see, at the 500mA draw rate, the mean capacity is about 3788mAh usable capacity. This is over 93.5% of the “stated” 4050mAh capacity which is an excellent result and implies the rating is quite honest, and the conversion circuitry is well able to take this regular load.
At the 1A draw rate, the mean capacity is 3591mAh usable capacity – some (about 2-5%) may have been lost in the USB cable and contacts (although short). As a result, the efficiency is above 88.6% (which is above the 85% claimed by the manufacturer), yet another excellent result.
Looking at the voltage graph, we can see the power bank is fairly well regulated (note the scale). Some shifts in level may have been due to temperature change during testing affecting the power bank’s reference voltage source, or a slight movement in contact – in reality, movements <0.05v are not significant.
One limitation is the slow charge time – it took a full seven hours to charge the power bank from flat (after testing) to full again. However, at least during testing, it was proved that the power bank had adequate end-of-discharge disconnection to prevent damage to the internal Lithium-Polymer battery.
The orzly Portable Power Bank is a slim, light and very portable power bank. It feels solidly built and is very similar in size to a modern phone, which makes it easy to carry. From my testing, it appears to pack the claimed 4050mAh power, which makes it a good choice. This is enough to charge even the hungriest smartphone from flat to full. It has a single output, up to 1A suitable for most phones but would not be recommended for tablets.
The package does not include a charging cable for your phone, but does include a microUSB cable for charging the power bank itself. If you use an Android phone, chances are, you already use a microUSB cable, so you can go ahead and use the one supplied to charge from the power bank. Unfortunately, you won’t be able to sync with the cable supplied as it does not connect the data pins.
The power bank is super-easy to use, just plug it in and go. The front power “button” is merely a capacitive touch-sensitive button that activates the power-level LEDs. It’s easy to inadvertently activate, so make sure you charge it up periodically (say, every month) to make sure it’s not flat when you need it.
All in all, it’s a good product and well worthy of your consideration. Thanks to MobileZap for providing the unit for review.
While we’re at it – maybe you’d like some mobile accessories for your new shiny Samsung Galaxy S5? Click here.