While I was in Hong Kong, I couldn’t resist the temptation to visit the “Mi Home” shop in Hollywood Center – basically Xiaomi’s version of an Apple Store, if I should be so bold as to put it that way. The biggest temptation was to be able to buy Xiaomi items at the advertised price with no mark-up and no chance of counterfeits. The downside, as I realized, is that while Xiaomi has a vast array of items on its China market, only a select few have made it to markets outside of China. As a result, the range was somewhat limited in the Hong Kong store, but at least it was convenient to visit, and I left with a few shiny goodies which deserve some mention.
Mi Power Bank Pro with Quick Charge 2.0 (PLM01ZM)
Seeing as it’s been a while since I last reviewed a Xiaomi power bank, it was rather interesting to see the whole range had changed towards slimmer models with one in particular (the “pro” model) offering Qualcomm Quick Charge (QC) 2.0 compatibility while still retaining a fairly attractive price. As QC is considered a “must” on many people’s shopping lists nowadays, I thought it would be a good idea to pick one up. (Note that some of these early images of the packaging were taken “on location” with a smartphone, as the packaging didn’t make the trip to save on weight.)
The unit above is the Mi Power Bank Pro, in grey (the only colour available). It boasts a 10,000mAh capacity, and comes in a shipping overpack even though it’s sold person-to-person in the store. There is still the scratch-off verification code sticker, but it is placed on the outside of the overpack. This unit is production-dated December 2016, making it quite fresh. Pricing was HK$199, or about AU$35-equivalent.
Inside the outer packaging is the more elegant inner-box which has a plastic-matte finish on cardboard and a simple Mi logo.
There’s a small leaflet, with basic usage instructions but all in Chinese. There is also a cardboard sleeve, in which the unit and cable are packed in. For convenience, there is a perforated tear strip to help “release” the unit from its packaging.
The unit is a matte grey colour, as promised, and branded in much the same way as prior Mi power banks. It’s a little smaller than a thin 2.5″ external hard drive and weighs in at 223.5 grams.
The interface is familiar, featuring a four diffused white LED indicators to show remaining charge/charging progress, which flash periodically. A button is provided to check capacity, however, an additional feature has been touted which is the ability to charge low-current devices (e.g. Bluetooth headsets, fitness tracker bands) which the automatic shutdown would interfere with. This is activated by double-clicking the button which activates charging for two hours (and results in a chasing-ascending LED display). Input to the power bank is USB-C, whereas output is via USB-A female socket. The choice for USB-C charging seems unusual for the time being – while it proves convenient for those with flagship phones with USB-C charging leads normally, it is a mess for those who still use microUSB-B requiring either a special adapter to use. At this moment, USB-C is still not quite popular enough but at least it seems to be looking towards the future.
The bottom panel illustrates the capabilities of the unit, which is both QC in and QC out. During testing, it was possible to perform pass-through charging as well although whether this works in QC mode was not determined. The unit is Made in China by ZiMi Corporation (an arms-length company of Xiaomi) and the date seems to be one month earlier than the external packaging claims (maybe because these labels aren’t so often printed). At least you will have a good idea about the age of the power bank from the label, so it’s a good “feature” to have. Regulatory logos are also included – a first time I’ve seen the SGS Quality logo feature on one of these units.
The unit comes with a short-lead as is traditional, however, this time the flat lead has been replaced with a more traditional round lead which feels somewhat stiffer than normal. The lead itself is for microB, and includes an adapter to USB-C. The best of both worlds, as long as you don’t lose the adapter.
It may be a slick unit, but it’s not exempt from a teardown, especially at its reasonable price. However, getting inside isn’t quite as easy as with previous units.
Removing the self-adhered and clipped front plate reveals the diffuser within for the LEDs, a black plastic frame which forms the unit and a button cover.
The button cover is removable, but any clues as to how to get the unit apart still prove elusive.
Instead, you need to attack the problem at the bottom, where two screws are used to hold the unit in place. Remove them and the unit can slide out of its shell.
Halfway out, and it’s already visible that the unit has a plastic frame with a thin metal shield as well. A bit more sophisticated, but probably necessary to keep the Li-Poly cell happy in all cases.
The unit consists of mostly a large Li-Poly battery and a single PCB. The Li-Poly cell has a barcode label on it and two self-adhesive foam strips to keep it somewhat snugly fit inside the outer casing. Space has been allowed around the battery for some expansion over the life of the cell – a good idea given the recent safety issues with cells that were a little too big to properly fit *ahem*. The cell ratings are not exposed on this side, and not even underneath the label. The pack itself is double-sided adhesive-taped to the thin metal backing.
My one concern is that the Li-Poly cell on this side has a dent neat the top-left corner of the image which was not a result of me tearing the unit apart. It seems something may have fallen on the battery during production or maybe a screw was lodged inside during assembly, and then removed and assembly continued. This damage to the cell, while not initially severe enough to cause a safety issue, could compromise the safety of the cell in the long run. In general, cells shouldn’t be stressed like this, so it’s a little disappointing to see this.
As is traditional, the pack has a thermistor placed in a special cut-out of the plastic casing. For QC capable units, this is highly advisable as one limitation to the rate you can charge at is the temperature of the pack. This ensures the pack is charged within its safe parameters.
The main PCB is a familiar blue colour, and is date coded Week 47 of 2016. The battery appears to be protected with a 15A PCB fuse (as a last line of defense), which is good to see. Two obvious TI solutions are used – a BQ25895 I2C controlled single-cell switchmode fast charger, and a TPS61088 fully integrated boost converter. Judging from this, the unit does not use any of the “all-in-one” QC solutions, and instead goes back to basics to do things with discrete power converters. This is likely the reason why this unit can do pass-through charging and is a little more expensive than a non-pro unit – there are two switching converters on it and so even with a single output, its complexity is on-par with a dual-rail dual-port output unit. The unit appears to be controlled by the chip labelled ZMD 1204UB which is likely to be a microcontroller (in contrast with the Abov units previously used). There is another small 6-pin IC (close to the logo) marked 48E 610 which is undidentified but could be protection-related.
The underside has a number of test points and smaller supporting components. Two 1.5uH inductors are used, confirming the dual-independent-switching-converters observed on the other side, both being higher-efficiency enclosed inductors. However, it seems the two units are subtly different (notice the different printing), so may come from different batches or different suppliers. The unit’s project code appears to be QPB100-MB 69-160419 – implying it was designed on 19th April 2016 (on my birthday, what a coincidence).
It seems that the raw tabs from the cells are spot welded to the board from both sides, and paralleled together by the PCB. This tells us that two cells are used to make the capacity.
And as expected, that’s why there’s Kapton tape all around the sides. So … after going through the efforts to release the cells from the holder without destroying them, who makes them are what is the capacity?
Et Voila! They are Amperex Technology Limited (ATL) cells of 5000mAh (minimum) and 5090mAh (typical) capacity per cell. As there are two cells, you can expect a minimum of 10000mAh of capacity, or typically 10180mAh. But it gets better, since this is an extended-voltage range cell, it has a “nominal” cell voltage of 3.85V which is higher than the 3.6V or 3.7V chemistry standard Li-Ions.
As a result, assuming you get the typical 10180mAh capacity at a voltage of 3.85V, the total energy comes out to be 39193mWh. This is equivalent to a regular 3.6V cell which has 10887mAh – so don’t let the numbers fool you. This unit even though boasting a number of 10000mAh actually contains more energy than the older, larger, slower and heavier 10400mAh original Mi Power Bank. Just goes to remind you that mAh is not a measure of energy, but merely charge.
The formerly “new” test rig has since been retired, due to now having a BK Precision 8600 DC Electronic Load on hand. As a result, testing now utilizes a cut-off portion of USB 3.0 cable (20cm) attached to spade crimps to the front terminal of the unit. As previously reviewed, the unit is quite accurate (beyond datasheet specifications), so my confidence in the results is greater. However, as it works as an active emulation of a purely resistive load, the ripple figures obtained are likely to be lower than via the former test protocol using wire-wound resistors. The inductance of the wire-wound resistors interacts with AC components (variations in) the current, resulting in a ringing which can amplify any unsmooth currents causing a higher ripple voltage. The voltage figures are also likely to be lower than the former test protocol as the load now enforces precisely 500mA, 1A and 2A load, rather than “whatever current happens” for a given resistance due to drooping power bank output. This pushes the units harder and gives a more accurate representation of what happens under a given load – however, in reality, most devices will sense voltage droop and “back-off” their current draw as this is a method dedicated chargers use to signal their limitations.
As this is the first serious testing with the BK Precision 8600, five test runs at each of 500mA, 1A and 2A were performed, taking a fairly long time to complete. The data was as follows:
|Load (mA)||Run||Capacity (mAh)|
|Load (mA)||Run||Capacity (mAh)|
|Load (mA)||Run||Capacity (mAh)|
Note that the figures are calculated for a 3.7V basis so as to be vaguely comparable with previous testing. The results are very impressive in general, and led me to believe the cells were in excess of their claims. Now after the teardown confirmed that they were typically 10180mAh in total capacity at 3.85V, that explained the higher-than-expected total output. Using this information and basing on typical capacity, the efficiency was 92.9% at 500mA, 92.8% at 1A and 88.5% at 2A although a slight amount of efficiency is likely to be lost in the cable. This might be attributed to one 2A run which had a slightly lower-than-normal capacity reading. It’s a fantastic result that far surpassed my expectations. The BK Precision 8600 also turned out some very consistent readings on the whole, with the exception of one run at 2A, and in future, running five runs may indeed not be necessary.
At this time, I have not designed a rig to emulate QC demand request signals to the power bank, and thus cannot test QC output capability directly. However, it is observed that using it with the Mi Max (below), the QC icon was shown next to the battery and charging was very noticeably quicker (and the phone got slightly warm during the process), indicating it was functioning correctly.
The measured voltage during discharge proved to be very stable, and appears to be tuned slightly higher than 5V but well within safe parameters to ensure some cable resistance is negated. The drop at 2A is very much likely mostly related to the 20cm of cable used in testing – however, it does replicate realistic use circumstances.
Ripple wise, at 500mA, it measured a peak-to-peak of 23.16mV, which is very good and below the necessary threshold to ensure safety.
At 1A, the ripple averaged 17.22mV, and again, a very good result. Oscillation frequency is still roughly in the 300kHz ballpark – not as high as some other products, but probably a good balance between inductor size/weight/cost and inductor losses/efficiency.
At 2A, the converter showed some strange stepping in its output, which had a pattern repeating at 116kHz, but also other components about the 350kHz mark. Ripple increased to an average of 32.28mV, but still well within the safe zone to keep devices happy.
The unit retains its opportunistic charging current optimization algorithm which results in periodic stepping of the current demand and observation of the charger response. This allows the unit to pull as much current as possible from the charger, especially during the early stages of the charging, and throttle back slightly to ensure safety in case the charger becomes over-stressed or cable connections are poor.
This behaviour was clearly observed, as my initial trials with an Asus 2A tablet charger resulted in a lower-than-expected current and longer charging time just over 7.5 hours. The resistance of the test shunt and cable connections, combined with the voltage-drop of the charger resulted in the unit drawing a lower current which it deemed safe.
By swapping over to the Xiaomi 2A charger, it did achieve and at-times, exceed 2A charging current as it was “deemed safe”. As a result, charging was completed in about 5.7 hours.
I also tested the unit with an unbranded QC 2.0 capable power adapter. Using a Keweisi USB Tester, it was determined that it was able to negotiate 12V output for speedy charging (unlike the Anker formerly tested which only negotiated 9V). The initial test resulted in the slow curve due to poor USB contact on the A-plug to the charger, resulting in a charge about 4.4 hours long. Once that was resolved by applying some pressure to the connector, a charge in as short as about 3.6 hours was achieved.
This illustrates the benefit of Quick Charge, and why so many consumers have grown accustomed to it, and demand it of their charging accessories.
Rather unsurprisingly, Xiaomi seem to have done it again, by making a new product that has won my favour by being good value, elegant in design, competent at what it does, and honest about its capabilities. In this case, it was a surprise case of promising a capacity which was the absolute minimum, rather than other manufacturers who like to claim maximum or typical figures. As a result, the results showed greater output than I would have expected. Efficiency proved to be good, and the dual-independent converter design provides the benefit of “synchronous charging” of the power bank and the appliance it is connected to. Because of its TI converter heritage, the ripple figures were good as well. Upgrades to functionality including the low-current override answers the prayers of tinkerers who may make low-powered 5V gadgets they want powered from a power bank without unnecessarily wasting power just to keep it on.
The only one thing I can criticise it for is the issue of the dent in the Li-Poly cell which occurred during manufacturing. Again, I stress that it was there as I slid the unit out of its cover, and such physical stresses to the cell may be a cause for concern due to the possibility for future failure. However, there’s a very good chance that this was just a one-off issue, and on the whole, the construction was neat and well designed.
On the whole, it gets my approval and has become my favourite power bank to carry with me when I need one … although even that is diminishing …
But I suppose this will all be moot, because apparently, the Mi Power Bank Pro has been upgraded to become a QC 3.0 capable power bank … for the same price.
Mi Max and Official Accessories
While I could have gone to the Mi Home just to get a power bank, that was not my intention at all. Instead, I was tempted by the prospect of getting a new phone to replace my LG D686 (2013) which is slow as a snail with a Mediatek (eugh) 1Ghz dual-core CPU, just 1Gb RAM, has no LTE or full HD screen or even GLONASS support, is on its second battery, and is stuck on Android 4.4 with no updates. About time for an upgrade. A big one.
Enter, the Mi Max. An affordably priced, 6.44″ phone with full high definition screen, 6-core Qualcomm Snapdragon 650 CPU running at up to 1.8Ghz and a monsterous 4760mAh (minimum)/4850mAh (typical) battery. Add to this, a 16MP rear camera with phase-detection auto focus and dual LED flash, 5MP front camera, fingerprint sensor, LTE support on bands 1, 3, 7, 38, 39, 40 and 41, GPS+GLONASS+Baidu GNSS, 3Gb RAM and 32Gb of flash.
It even has dual SIM capabilities, although I would rather sacrifice the second SIM slot for the ability to use a microSD slot. The whole lot cost just HK$1599 or about AU$275 outright. Of course, there were other options, but I really wanted the larger screen and larger battery. After all, I’m travelling on holidays and I’d really not want to have to use a power bank if I didn’t have to.
When you first open the package, you are greeted by the phone right away with an explanatory cover over the screen, and a few labels on the rear ot protect the camera and provide some regulatory information. The unit is a pleasant gold colour, with a 2.5″ screen that curves away gently at the edges. The fingerprint sensor on the rear is an added convenience feature as well.
It comes with a small diagrammatic quick start leaflet and a regular 5V 2A power adapter – British plug for Hong Kong of course. A black USB A to microB cable is also included. It was a little disappointing to see they didn’t bundle a quick charge capable charger, as the Mi Max is absolutely capable of it. However, I suspect this helped save on cost, but also likely strains the battery less in regular operation due to lower charge current and heat – so might actually have a secondary benefit in prolonging battery and device lifetime.
The front has a very simple design, with no obvious Mi branding. Its discreet looks are definitely an asset, and the 6.44″ screen takes up the majority of the width of the unit, leaving a very small bezel on the sides. Rarely, this proved a little inconvenient due to the inadvertent activation of touch elements at the edges. There is an additional window for an ambient light sensor and proximity sensor to poke through.
But that’s not all. There were also official accessories for sale, so I decided not to leave my Mi Max to fend for itself. One accessory is the smart cover which has a very similar gold colour pleather soft-touch exterior punctuated with a multi-layer plastic window which allows for viewing the LCD and finger touches to be detected (e.g. for answering calls, or quickly glancing at the time). It is a perfect fit for the phone, with holes for the camera and fingerprint sensor, but is structually slightly weaker near the camera hole, where the clip is more easily released from the phone. However, this isn’t really a major issue – as long as you resist the temptation to play with the clip constantly.
Xiaomi also sells screen protector film for the phone, three plastic protectors in a packet with de-dusting labels. One issue is while the case’s front window provides convenience and protection for the LCD, when you have a plastic protector on the screen, any trapped dirt or grit scratches the screen protector and the interior of the front cover. That’s something that happened to me.
As a result, when I got home, I upgraded to a tempered glass screen protector, where another issue surfaced. Even though the new glass protector didn’t itself scratch, the casing window continued to scratch, and the 2.5D surface of the phone which curves away at the edges makes for edges where most third-party glass screen protectors will not adhere properly resulting in a space where dust can enter and the visuals are spoilt somewhat.
As I had intended to transfer operation to this phone immediately while overseas on holidays, the set-up process provided a few unexpected hurdles. For those who don’t wish to run Xiaomi’s official ROM (global or otherwise), they will find a locked bootloader in most modern Xiaomi phones. While it’s not impossible to unlock, it now requires filling in an application with a unique reason, a Mi account, registration of the device towards the account, receiving an unlock SMS via the Mi account registered mobile number, and using a PC with the necessary software to perform the unlock. There are restrictions on the number of devices you can unlock (one per month, if I recall correctly) as well.
Luckily for me, I was able to meet the challenge, as my registered account number was attached to a GSM modem at home where I could remote-in and get my code. After unlocking, I flashed Xiaomi.eu and was on my merry way with Android 7.0, MIUI8 and a good number of customizations I was familiar with using it on my earlier Xiaomi Redmi Note 2. From there, getting set-up was no major difficulty.
Compared to my Redmi Note 2, the larger screen was very noticeable, although the default DPI settings do not seem to make the most of it. Once I had rooted the phone and altered the DPI setting to something more to my liking, I could really begin to fully benefit from the larger screen which meant more detailed maps (useful when walking around in a foreign city). The screen was quite acceptable, although its maximum brightness was a little limited. The speakers were decently loud, but a bit tinny. I use the headphone jack most of the time anyway (… chuckles for absolutely no reason at all).
But one of the biggest benefits compared to the Redmi Note 2 was that the battery life was amazing. On a heavy day, I’d only chew through 60% maintaining all-day LTE connectivity with a SIP softphone client registered, and all of WeChat, LINE, WhatsApp, Facebook Messenger, Skype and three different e-mail clients running in the background, while hosting my Mi Band 2 fitness band for notifications as well. On days connected to Wi-Fi, sitting at home, the unit could easily sit there doing push notifications for 5 days or so before needing a charge. The Redmi Note 2 wouldn’t even last four hours under this load. But as a result, I have the confidence to leave the house without a power bank. If a QC port is available, the Mi Max also does a great job of soaking up charge quickly, as it is QC capable.
Another saving grace was the sensitivity and throughput of the Qualcomm radio. In a few places, notably a hotel room, I was not able to get any data via LTE on my Redmi Note 2. Swapping the SIM into the Mi Max resulted in a stable, albeit slowish connection. It’s much better than having no connection, especially when relying on the phone as your means of connectivity.
Performance wise, I had no qualms – it performed much better than my other devices, and while not quite “flagship” performance, it was more than necessary for most mainstream users. Despite this, it wasn’t inefficient in the way it used power, although at times I did find it “sleep” a bit too deeply resulting in stuttering audio playback with the screen off and delayed push notifications. Probably a bug related to my customized ROM, however.
I have yet to experience any reliability issues either. Build feels solid enough to handle every-day use, although the side gold trim around the speaker and USB connection feels like plastic, it hasn’t yet shown any scratches. The use of the older microB connector is more “compatible” but might also be criticised for being a little dated now. The microSD slot was an absolute necessity and hosts a 128Gb Samsung card (with permissions fix to enable apps to access it) with absolutely no trouble and decent performance. The better GNSS receiver also produced even better tracking than my standalone Garmin etrex10 high-sensitivity GPS receiver, and locked on more rapidly than my other phones – another positive for the traveller. One downside seems to be the finnicky fingerprint sensor, which works well for a few days after recording the fingerprint, but then becomes very sensitive to pressure differences afterwards, leading to a constant battle of retries. Apparently, this is an issue not unique to this phone, and applies to many rear-mounted fingerprint sensors in general.
In short, I like this phone a lot. Most of the time, I really don’t mind who makes my phone as long as I can do what I want with it – and the Mi Max definitely fits my needs at a price which is extremely reasonable. Over time, MIUI has rubbed off on me, and the Xiaomi.eu ROMs have been set-up in a way which I am comfortable with. Unfortunately, the Mi Max doesn’t seem to be available in Mi Home (HK) anymore. However, a similar offering featuring 8-cores, more LTE band support, a slightly smaller screen and about 500mAh less battery can be had for a lot less in the form of the RedMi Note 4X, so I suppose there’s always good value to be had from Xiaomi.
Mi Band 2 (XMSH04HM)
Almost a year ago, analysts noted the launch of an OLED display-based fitness band from Xiaomi, but only available in the China market. Lucky for me, it was also available in the Mi Home in Hong Kong.
As a long-time Mi Fit user that’s gone through the original Mi Band and Mi Band Pulse, the Mi Band 2 was a welcome advance over the simplistic three-LED indication provided by the former models. The unit was available for HK$199 or about AU$35, not particularly expensive. As a result, Xiaomi appears to have taken the crown from Fitbit for wearable sales.
Again, the unit features simple packaging, but contrasts from the older Mi Band units by being in a slightly larger form factor. This is because it has a larger 70mAh battery (due to increased power demand) and an OLED display. Charging current is specified at 65mA maximum, with an IP67 rating and updated Bluetooth 4.2 Low Energy connectivity. It is compatible with devices with Bluetooth 4.0 and Android 4.4 and above, or iPhone 4S and above with iOS 7 and above. On unboxing, you are presented with the tracker unit itself, with a band, quick-start and charging cable included. Changes include the need to thread the tracker into the band from the rear instead of the front.
The unit features heart rate measurement using an optical sensor, although the sensor appears slightly different to the previous models. Upgrading to the new unit was as simple as charging the band (which takes a while), unpairing the old, and pairing with the new.
In my opinion, the Mi Band 2 was a worthwhile upgrade. The inclusion of a capacitive touch button and OLED display did not diminish the battery life much, and it is still possible to go almost a month between charges. The display, however, fixes a few issues including the inclination to stare at one’s wrist for the time (and realizing with the old unit, that you can’t read the time with it). It also provides clear information of the steps, distance and calories burned and a mechanism to request an immediate spot-check of your heart rate.
It also makes the notifications feature of the band a lot more useful, as it is possible to understand why the band is vibrating without having to look at the phone. However, the OLED display is only capable of displaying a pictorial icon signalling which app had caused a notification (popular apps have customized icons, some less popular apps may only show an icon saying “app”). The text of the notification or any ability to reply is not provided, so it is a little behind some others which at least provide one line of text. Given that the display is only a short rectangle across the face makes this limitation understood – while the whole front is glossy with the exception of the touch button, the display is only a small fraction of the surface.
The increased size and bulk were not noticeable in everyday use, and while the front is glossy plastic, it hasn’t been severely scratched enough to notice despite taking a few bumps. It also feels more secure in place, being loaded through the rear of the strap, with the strap itself feeling slightly more durable (nothing’s broken off yet). Compatibility with old Mi Band accessories, however, is lacking as a result.
In all, not a bad device, and a purchase I really wanted to make. The other benefit is that using it with Smart Unlock also means there’s another way to unlock the phone for convenience just by being in proximity to it.
Mi Scales (XMTZC01HM)
While all the other products came in white boxes, this one retained its “natural” pulp coloured box. Sadly, I disposed of it before taking photos, but the item in question is a set of smart bathroom scales that connect via Bluetooth Low-Energy to help you track your weight with the Mi Fit application. Normally, one’s weight is something to be feared, so I didn’t enjoy buying this product … until I saw that it cost HK$139 or AU$24.
There’s not much to say about bathroom scales really – but this unit was pretty well built. It features a glass top (which seems pretty nifty for the price) and a hidden LED display that shines through the white coating at the top. The scale powers on and measures as soon as you stand on it, and powers down automatically – no need to wait for it to zero. Recorded weight is automatically downloaded into the Mi Fit app, so it’s very convenient.
The rear has a battery flap where four AA cells are needed. Due to low power consumption, even crappy carbon zinc cells (above) work just fine, but I don’t recommend it. At least the batteries are common ones which are inexpensive, so replacing them is not a big issue. They should, however, last around a year. Above it is a switch that is used to switch the units used in weighing – Jin, Pounds and Kilograms are available. Four rubber feet are used to stabilize the unit.
The weight range is 5kg to 150kg, which is a little more than your average scales, but is probably a sad sign of where the world is going. I’ve used it a few times, and experienced no issues – put the batteries in, pair it inside the Mi Fit app and it’s pretty much get-on-get-off and you’re done.
As for how much I weigh … lets keep that a secret. But Xiaomi knows.