Review and test of two 10000 mAh power banks
Hi there I just, came back from a holiday involving. Lots of hiking and I took these two power banks with me, both. Claim a capacity, of 10,000. Milliamp hours. Although. During the trip I found one I'm noticeably. Longer, so. Now, that I'm back in the lab I thought it would be a good idea for a quick review and on, some tests. These. Power banks are still in use by the family, so I'm not going to take them apart for. Now but. Let's see what facts we can determine just from the outside. The. First one is the energizer, Yui, 10007. Above. Ice surface, and blue, end cups, the. Box shows the key specs, capacity. 10,000. Milliamp hours, and an, energy, content, of 37. What hours maximum. This. Of course means, that the 10,000, milliamp hours, are based on the average lithium. Battery voltage of 3.7. Volts and, the. Usable capacity at. The 5 volt output will, be significantly. Less. It. Charges, at 5 volts 2 amps, over microUSB. And has, an output rating of five, was 2.1. M it. Does not say how that applies to one or both outputs. The. Weight is stated as 240. Plus, minus 24, grams and, I wonder why, that huge, uncertainty. Of plus minus 10%. The. Only thing I can think of is that they, may put in cells from different manufacturers. My. Unit weighs. 239. Grams and I paid 23, pounds for that in, a local shop I know, way, too much but, I was in a hurry and I needed this power bank for a next day trip, the. Small piece of paper that came with it can hardly be called a manual it. Basically repeats the specs from the box in several languages. While. The reverse gives basic, how to connect, information and, explains, what the for charge status LEDs, mean, nothing. Special here. The second one is from Xiaomi, there. Are many Xiaomi, power banks out there and many, of them are fake this. One came from an eBay seller. Skycity. 19:4, on 15, pounds and appears to be genuine, the. Unit is in a sleek metal enclosure, the. Box came in one of those security, seals and, it did check out on Xiaomi. Website. The. Manual in the box is completely in Chinese but. Thanks, to the internet and English, manual is easy to find and download. The. Capacity is again ten thousand milliamp hours, and 37, watt hours energy, I like, that they specified, two capacities. The. 10,000, milliamp hours, for the lithium battery at a nominal voltage of 3.7. Volts and, the actual, usable. 6500. Milliamp hours. Available. At the 5.1, world. Output. This. Is an old pair. Of mine, and I have made a video explaining why, these two capacities, are necessarily, different so. Hats off to show me for giving both values, the. Energizer, is of course silent, on that matter, other. Difference, to the energizer, are that the Xiaomi can charge fast using, 9 volts if. The power supply supports, it and it can produce, 5. 9. Or 12 volts, outputs, as well, not. Stated, is the weight which is 251. Grams, for my model so 12 comes heavier than the Energizer. Charging. The energizer from empty, using, a samsung power adapter, that can provide 5 Falls to m/s or nine, volts, 1.6, 7 amps, I'm. Using the wu-tang um. 34c. USB, tester, to keep track of the charge going into the power bank in case. You're interested I've put a link to my review and teardown, of this USB tester, in the description, below. Charging. Takes several hours of not. Much happening, so let's cut right to the end. So. At 4 hours and 46, minutes the, charge current drops to zero, it's. A bit hard to read but we have pumped, in. 8400. Milliamp, hours or forty. Three point two seven six what hours into, the energizer, power bank. Let's. Do the same for the xiaomi which, is also completely, discharged. The. Setup is the same as before. It. Is interesting that the xiaomi does not shift to the first charge mode promised. In the manual it stays. At five wolves for the whole poses. Initially. I thought it might be because the Samsung, powered up time using only office nine volts at one point six seven amps instead.
Of The nine was two amps stated, in the xiaomi manual but. I tested, it is a motorola power adapter, which offers, nine, was two amps but, the xiaomi was not impressed and stayed at five walls. Around, 5 hours and 20 minutes later the. Charge come on tops to 40 milliamps, and it stays that way, probably. Some, form of trickle charge or just, to drive the charge indicator LEDs. We. Have put in nine thousand, one hundred and fifty two milliamp, hours or forty, seven point. Two zero one watt hours. That. Is about nine percent more, than went into the energizer, I decided. To investigate the problem of the missing fast charge of the Xiaomi further, and it turned out that both the power adapter, and the USB keeper by the problem, the. Cheap cable, I used happen to have have, only two wires for, power and no data connection. When. I changed, this to this four wire flat cable, and the. Motorola, adapter, the, Xiaomi, switches, to nine was charging, without problems. It. Starts at about one point eight amps but I discovered, that the current comes up later to the full two amps, with, the Motorola and after getting wrongly, hot in the process. While. Shall, me thanks to its large metal, case just, feel slightly warm. Just. For the record I did also try using this cable and power adapter the energizer, but, it always stays at fire falls. Fast. Charging doesn't, work with the same khayru but the Samsung power adapter, even. Though that adapter, can fast charge my phone with, nine volts at 1.5, amps as. These two adapter are the only ones I have that can do fast charge I don't, know if there's a compatibility issue but. My guess is that, that Xiaomi simply, asked for nine volts two amps and since, the Samsung adapter, can only deliver nine was at one point six, amps, fast, charges never started. For. Discharging. I'm using my electronic, load the. Build of which is in another video I linked below, it. Is setup in four wire mode so, the extra sense input, compensates. For the voltage drop across the wire from the battery to, the load. The. Load is set to constant, two amps. The, Energizer, is first. Discharging. Takes against several hours and apart, from the slowly reducing, charge indicator, LEDs, nothing. Much is happening, the. Output voltage of the Energizer, is not great, only. Four point eight nine volts, this, means connected. Phones or tablets, will charge a little slower. Finally. Three, hours later we reach the point where the energy of the power bank shuts down. In. Total we extracted, six, thousand, and thirty, nine milli amp hours, or. Twenty. Nine point five three what hours, let's. Try the same as I show me the. Setup is identical, including, the discharge, current of two amps. It. Is immediately, obvious that, the voltage of the show-me at the same law is slightly above five volts, much, better than the four point eight nine of the energizer. About. Three hours and 15 minutes later, I shall meet power bank shuts down -. In. Total we extracted. Six. Thousand five hundred and ninety one milliamp, hours. Or. Seriously. 0.18. Watt hours. Here. Discharged, results, which by the way confirm, what I experienced. When using these power banks, during my travels the. Xiaomi has a bit more capacity and because, it maintains its voltage slightly above, five walls compared, to the disappointingly. Below, four point nine volts of, the Energizer, charging. Your phone goes, a bit quicker to. The. Xiaomi matches, his stated capacity, of, 6,500. Milliamp, hours, at five walls but, neither power bank did, deliver thirty seven thousand milli watt hours based. On ten, thousand milliamp hours. Times three point seven volts with, this discharge current because. Of the losses in the boost converters. Indeed. From an efficiency, point of view both are not great in generally. On all, power banks you put more energy in, to it then, you can back out for. The two amp discharge. You. Already saw the efficiency, is slightly above 70%, for. The Xiaomi, and our own 68, percent for the energizer. At lower. Cons it's a, neck-and-neck race with. The energizer, leading at 1 amp and the. Xiaomi at 0.5. Amps, but. We are still just getting at best, 75%. Or three-quarters.
Of The energy back that we put in this. Is a bit disappointing, because from, other smaller, power banks, are tested earlier I would, have expected higher, values, of 80%. Or even 90%. For. This test I want to check the response to increasing, load and overload conditions, I'm, using my poem 1 device for, recording the, behavior, there's. A whole series of videos in my channel about, designing, and building this tool links. Again below. Once. The recording is started I'm. Increasing, the load current in 200, million, steps. There. Is a small voltage difference, between the display on the palm one and the electronic, load because, of the top across the zero point 1 ohm shunt, resistor, in the power. Similar. With increasing. Current there is a noticeable, voltage drop across the wires from the power bank I measure. The resistance, of the wires to be 70, millions which allows me to correct the readings later. At. Full load of 2.1. Amps, and above the. Energies, are still going but, its voltage is sagging, ever more. Okay. At 2.9, amps, the Energizer's, protection, circuit activates, and turns, the output off, now. Both power banks have two outputs, so, it makes sense to check how they behave if both are loaded. Unfortunately. I only have one electronic, load, therefore. I'm going to use this, light as a USB tester, as a second, load, unfortunately. Its current, is of course somewhat voltage, dependent, it. Was around saying at 80 milliamps at, fire Falls which, isn't that much but it, should allow us to see if it makes any difference, I'm. Running the same test as before, but now with the extra load of around three and at 80 milliamps, the. Light is just out of you to avoid totally, swamp in the camera. It. Is interesting to note that the voltage at the highly, loaded output, is dropping while the voltage the output driving. The light is almost unaffected, until. Close to the end. Which. Happens at 2.6, m/s this. Time compared, to 2.9, before, with, only one output this. Makes sense because the, difference of the milliamps. Is about the extra, current we were drawing from the second output. Repeating. The same test they show me first, with one output. It. Is. Interesting to note that the output voltage actually. Increases, slightly in a moderate load of 0.6. Analysis applied. But. At ever-higher cones, the measured output voltage, decreases, as expected. Hardly of course because of the voltage drop in the wires. At, 3.0. Amps the show-me had enough and turns the output off. Repeating. The same test with the second output loaded. The USB, light by other USB tester. Notice. How the voltage on the second output increased. Again after, the electronic, load added 200 milliamps to the total. As, with the Energizer the second output voltage, remains quite, constant, despite the increasing load on the first output. As expected. The power bank turns off when the combined current, from the electronic, load and the additional, light exceeds, about three amps this. Matches the spec which, states that the maximum load, is 15, watts for both outputs. Here. The output falls over, load current, plots from the four load tests. Energizer. On the left and show. Me on the right we. Can see that in all cases the output voltage, slowly, tops, as the. Current increases, also. The Xiaomi, has this slight, bump where. It's boost converter suddenly, increases. The voltage slightly, possibly. Because it is switching, to a different mode. Noticeably. In all cases is that the energizer produces. A lower output voltage. And, turns. Off at a lower overall current. To. See how the energizer, handles, a phone that is capable of fast charge I connected. A Samsung a 40 to it as. Expected, it can't support this and charge that slightly below 5 was at one. Point two amps. Resulting. In 6.2 five watt hours of energy, transfer, from the power bank to the phone the. Same test as I show me which should support, first charge. It. Starts at 5 volts and then immediately switches, to slightly below 9 volts at 1.5, amps which, is thirteen point two six what hours of energy, transfer, double. That of the Energizer. To. See if it can provide the promised 12 volt output as well I connected, a USB trigger tester, in between the UMC 34c.
And The power bank, all. This little device does, is to send a quick charge 2.0, 3.0. Command, to, select five, nine or 12 volt depending, on the selector switch as. You, can see the Xiaomi supports, all three settings, of. Kemara, R and a simple discharge, test at 12 volts while when I came back just before the test ended, it appeared, that the Xiaomi has switched to 9 volts all by itself, to. Find out more I repeated, the test, but, as you can see this, time I recorded, the behavior, using my poem on tester and, since. I have the poem on running anyway I decided to record the behavior, at different, currents at the same time but. Then let it discharge at, the Xiaomi stated, maximum, of 1.2. Amps for 12 volts. And. Sure enough about, halfway in the discharge something. Strange is going on the. Voltage is jumping, up and down like crazy. After. About two and a half hours the power bank cuts off with, a total of thirty two point seven one what, hours energy, delivered, he. Is the plot of the total discharge, the. Efficiency, for 12 volt 1.2. Amps is not great at, just 68%. Immediately. Obvious is. This weird behavior, in the middle I try. To zoom into this but static laughing is just not up to that so. I used the same little interactive, Python graphing, utility, Award for my video about an ants Minh battery charger, I, saved. The sequence, of views of the data earlier, and, but just psyching through them you, can see, first. The zooming into the crazy jumping, up and down region. Revealing. More and more details, and. Then. As a progressively. Scroll, to the light. The. Voltage fluctuations. Are having less and less amplitude, and finally, settling, on a new, lower, value. It. Could be that this behavior is, caused, by my setup not falling they expected, quick charge protocols, I was. Trying to find a speck of the protocols, but it appears that the whole handshake, and comms are already baked ready, to use into hardware chips for. Example, Snapdragon. Processors. My. Concern, is that, since. I'm basically. Always commanding. 12 volts, it, may be that, as the battery drains the, Xiaomi announces. And starts a downgrade, to, 9 volts which. Would probably be accepted. By a phone or tablet but. My dumb USB, trigger device commands. It right back to 12 volts, this. Repeats, more and more until. The Xiaomi, decides that it just can't do it anymore and ignores. The 12 volt command. Be. That as it may, let's, playfully look at the beginning of the plot, why are times up the current. The. Red line is the plot of the current, increasing, from, zero. To one point two amps, and the blue, line shows the. Voltage topping. From, just below. 12 point 4 volts, in. Idle, to around 12 point one at full, load, there's. A small area, where. The load is below, about. 0.5. Amps, and the, power bank seems to put you some fluctuations. But. This high resolution blood, really, accelerates, the effect the, fluctuations, are really very small about, 20 millivolts, and harmless, I, tried. The same setup with, a USB trigger, tester, set to 9 volts. First. Recording. Of the current amp up. For, nine walls we go all the way to two amps which, is the specified, full load setting, for the show me at nine volts, and. Then. Letting. It run at 2 amps until, it's completely, discharged. The. 9 volt 2 amp load curve is on the left here you will, notice that now we have two, areas where large fluctuations. Occur, from. 9 volts down to 7 and later, from 7 volts down to 5 the. Spike at the end was caused when the Lord was disconnected. The. 9 volt efficiency. At 2 amps is just. 66%. Slightly. Worse than for 12 volts. For. Good measure I repeated, this test with 1.5. Amp Lord which, is what, my phone normally tours. When. It's fast charging, and in this case we, are back to, one area of fluctuation. From nine walls down to seven, which. Also occurs, much later so. With just, 75%. Of the maximum, allowed load the show-me managed, to avoid downgrading. To 5 volts as it did before and the, efficiency, has also improved, to 70%. The. Current ramped up and the. Voltage response at. The beginning of my 9-volt, test looks. Perfectly, normal, as. I mentioned, before I suspected. The problem of the fluctuations. The, cost per my USB trigger, testing, refusing, to let the Xiaomi downgrade, the, voltage when the battery drains and the boost converter can't, maintain the higher output, voltage any longer. To. Test if this is the case I decided, to repeat the 9-volt test but instead of my USB trigger, tester, and electronic.
Load, I'm simply, connecting, my Samsung phone which. Supports, fast charging I, made. Sure the power bank was only about half full to, increase the chances that it would want to revert to a lower voltage, this. Plot is shown on the top here. For. Comparison, I did the same test that replaced, the Xiaomi power bank with a Motorola, power adapter, so, lack of charging capacity. Is no longer an issue this, is the lower plot here, the. Results, are quite interesting. Firstly. In both cases the car is cycling, priority, every, 30 seconds, between, 1.5. Amps and, 0.7. M/s which. Is caused by the charge controller in the phone. Secondly. As expected, in the top graph the, Xiaomi, shows increasingly, fluctuations. As it struggles, to deliver 9 volts, but. Because the current cycles. This. Phase is torn out because, of each low current, phase show, me recovers, back to 9 volts. Eventually. It can deliver 9 volts only at the low current phase and. So from, their own the. Voltage cycles. In sync with the current, between nine one and seven balls. So. In conclusion my. USB trigger, test that wasn't, the cause of the fluctuations. It. Is simply something the xiaomi power bank does when its internal, battery voltage falls too low that's. Not least a quick look at how they show me fast charges, from a quick charge compliant, motorola power adapter, rated, at 5 volts 3 amps, 9, volts 2 amps, whatever, fault 1.5, amps to. Record this I use the Bluetooth capability. Of the UM 34 C and the, recording, capability. Of The Associated app. As. You can see the adapter, and power bank agreed, to use 9 volts 2 amps which, is fine as it uses the maximum, 18 was possible, in quick charge 2.0, a. Plot. Of the recorded, data looks, a bit unexpected. It, appears that charging, the Shou is anything, but straightforward. Looking. At the red line which is the current we, see many short gaps where, the current drops to half or even to 0 for moment of, all, the, current ramps up to 2 amps but. Then increasingly. More frequent, tops. To just. Over. 1 amp for extended, periods. This could well be the result of summer protection. Kicking. In either in the show-me or the power adapter, or both, it. Is also possible that the short passes, a chemise, version, of pulse charging. We. Saw a similar pattern when, looking at charged current, produced, by the unspent battery charger, in one of my earlier videos a, bit. More worrying is the, blue line showing, the voltage, there. Are two or three short voltage, spikes of up, to 15, volts magnitude. He. Has a zoomed in view of some of the spikes, I'm. Not sure if this was caused by the power bank or the power adapter, but, it seems that neither mind too much I, only. Have one power adapter, that supports, an 9 volt 2 amps expected, by the show me so I can't try another adapter to see if it behaves differently but. What I can do is, to take the same power adapter, use my USB trigger, tester, to set it to 9 volt loaded. With 2 amp current, and record, the behavior, with my power mode the. Result is this graph here as. You can see for. The whole time I loaded. It with 2 amps which, was almost 1 hour the output, is rock-solid. The. Adapter, got very hot in the process but kept on going she. Can conclude, that the fluctuations. And the current reductions, we have seen earlier are all caused by the show me and not the power doctor. In. Conclusion, there's, no question, that despite, the strange behavior in, some instances, the, Xiaomi is the more capable power, bank and that at.
A Far lower cost, but. Interestingly, specs. Are not everything, when it comes to what people like. Given. The choice everyone, had asked to choose one, of the two for taking on a hike or even just a long journey went. Immediately for the energy even. When told that the other one had more capacity or, could, fast, charging. The. Chunky rubberized, exterior is. Much nicer to handle and it gives confidence of, throwing it into a backpack without, much, voice, the. Sleek metal housing, of the show-me, on the other hand is rather slippery. Scratches. Very easily and, it just doesn't look and feel like a device, meant, for the on-the-go usage, I. Hope. You found that little comparison, useful, and thanks, for watching.
2019-09-01 00:20
