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Xiaomi Power Bank 3 Pro 20000mAh USB-C $42.95, ZMI QB815 15000mAh $38.95 + Delivery @ Shopping Square

780
XM20

Xiaomi Power Bank 3 Pro 20000mAh @ $42.95 + Shipping

ZMI QB815 15000mAh $38.95 + Shipping

Apply the coupon code XM20
to get the offer, Discount shows at Checkout.

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closed Comments

  • +2

    Is this a good price for the ZMI QB815 15000mAh? Also, has anyone had experience buying from this site?

    • +1

      shopping square scares me :/
      i really want Xiaomi Power Bank 3 Pro 20000mAh for a friend and one for my mum though !
      i would totally recommend PB3 Pro.

  • +1

    Great price on the 20,000mAh model. I bought my last one for 199RMB in China (RRP) which is roughly $40. Great to see them locally with basically no markup.

  • +3

    Just an FYI, anything thats 10k+ is really QUITE big, and a noticable (but managable) weight even in a backpack.

    These sort of things youd use for a family camping trip, or if you run actual 5v appliances while out, like lighting or fans.

    With possibly the Nintendo Switch, and iPad pro, as an exception; if you leave your house with a charged phone on Friday, and expect to be home on Monday, you still only need half this size.

    I love my power banks, but so many friends have bought big ones, only to never carry them, because theyre heavy!

    • Thanks for the heads up. I will be using it to charge my S10+ mainly. Is the ZMI to big to carry around? if so, which one do you recommend to get?

      • +1

        S10+ has a 4100mah battery

        Add 20% for voltage boost losses inside the charger (taking 3.75v, to 5v).

        Add 5% for 5v regulator inefficiency.

        So, a 5000mah power bank should get that phone from 0% to 100%.

        Depends how many charge cycles you expect to have away from a PowerPoint, and if you're actually draining to flat.

        • +1

          Almost correct.
          Being that the destination battery is also ~ 3.75v you either have to subtract the 20% that you add at the start or just ignore it.
          Also regulators are not really 95% efficient, closer to 90% for a good one.
          Doest stop manufacturers making those claims though.
          World would be a better place if battery capacity were measured in watt hours, then the only consideration is regulator efficiency at either end.

          • @virtual81: Buck converting is more efficient than boost converting.

            • @MasterScythe: Hence why the 5% loss for the 5v reg (boost reg) is not a sensible figure.
              Some of the best implementations of buck regs I've seen still struggle to hit 90% efficiency in practise (regardless of claims otherwise).
              Boost regs are a little worse, but not that much.

              • @virtual81: No, I said 20% for the boost circuit, and 5% for the regulator.

                • +1

                  @MasterScythe: I'm lost… the boost circuit is the 5v regulator.
                  There is no other regulator unless you count the 4.2v CC/CV charge circuit in the end device.

    • Yeah this is 100% true IF your main use is for charging phones - I almost only ever use 5k/10k Xiaomi ones. But I haven't found a small powerbank that can do a MBP. So I do love the convenience of grabbing my 20k ZMI when I know my laptop won't last the distance and just need the extra juice to get through the day.

  • I guess this can charge surface pro 7?

    • Hey good point. With PD profiles there will be a few ultraportables that it will apply to also; fair.

    • +1

      I have the ZMI for this purpose, and yes it does!

  • I bought this for my daughter's XPS 13, so wanted this higher capacity (and also as a first PD-capable battery pack). Paid $60 and it was well worth it compared to other units with similar specs.

    Note: charges only on USB-C port (I use it with the USB-C PD originally charger from the laptop or the USB-C monitor.

    I'd definitely consider this a bargain (tempted to buy a 2nd) if you need this higher capacity and PD.

    • Yep, I'm looking at one for my PD laptop, delivers 45w watt via usb-c (15v @ 3a)

      Output: 45W MAX
      USB-A(Single port): 5V2.4A,9V2A,12V1.5A
      USB-A(Dual USB): 5V3A
      USB-C: 5V3A,9V3A,12V3A,15V3A,20V2A
      3 Port: 5V5.4A, 9V3A, 12V3A,15V3A,20V2A

    • does 45W max output mean that it won't be able to charge batteries that require greater charging power, e.g. 60/90W, or will it still charge but simply at the max output of 45W?

      • It would normally mean it can still charge, but it could be device dependant.

  • Bought the Xiaomi power bank a while ago, and it's great, charges my Surface Pro on the go with a USB-C adapter (connected to the SP charging port).

  • Does the Xiaomi shut down if my device uses very little power for a period of a few minutes?
    Most power banks I have do this. At times a GoPro fills its internal battery, then take no power for a while before wanting more but none is coming.
    TIA

    • +3

      Double-press the button to enter "low power charging mode" it'll be handy for charging bluetooth headphones, fitbit etc.

  • I bought a QB815 at this price from Shopping Square with their deal a couple of weeks ago. It arrived very quickly and the ZMI website confirmed that it was a legit product. I’ve since used it to charge my MacBook Pro 15”, and it manages to put out enough watts to charge it fairly quickly if I’m not doing anything too heavy on the laptop. Overall I’m very happy with this power bank.

  • This would charge a Surface Book 3 right?

  • Would this be too heavy to balance out the weight on the oculus quest headset?

  • Wow, that's the largest power bank I seen for a mobile device, anyone know what is classified as the largest consumer grade power bank in the world you can carry.

    • If you're referring to on an airplane, its 100Wh; or about 26800 mah in power bank form.

  • Pretty sure I bought this exact one on a previous deal from the same crowd.

    Pros:
    - Does what it says on the box
    - Sleek design
    - Can trickle feed a 15" MBP

    Cons:
    - Heavy, which is entirely expected for such a beefy powerpack
    - FCC/Flight safety: The capacity is not printed on the device. I followed advice from OzB and traveled with the box, the theory being that if you are stopped and they will not let you fly with it you have to show the capacity somehow. Never been asked after several international and domestic flights.

  • +4

    I want a deal on the ZMI QB823 for my next power bank.

  • Can either of these charge a mbp 16"?

    • +2

      Yes both. But very slow if you are using the mbp

  • -3

    Stop putting Aussie flag next to a Chinese product.

  • I have the xiaomi power bank, it works with Evey other phones of mine, except my new oneplus 8 pro.

    • You mean it doesn't cast charge, or doesn't charge at all? OnePlus have never used PD or QC that I'm aware of, so don't expect 'fast charge', but possibly charges at 10W from this bank.

      • It doesn't charge at all. But I found it only happens when using the cable on the charger that came with Oneplus, if I use other usb cables to connect the charger and the phone it fast charges just fine.

        So all good now.

      • Mine charges the phone now, but only when using the cable that's didn't come with the charger.

        Don't know why, but it doesn't really bother me.

    • I have the Xiaomi Power Bank Pro 3 and a OnePlus 8 Pro and it charges fine for me.

      Obviously doesn't do Dash or Warp charging but it does do the standard fast charge (5V at ~2A = 10W). This is over USB C cable (I don't have USB A anything anymore and it's wonderful).

  • So for charging a modern laptop with USB C (Lenovo, HP, Macbook etc), which of these two options is the best if the capacity difference isn't a factor?

    • ZMI since you can use it as a USB Hub while charging as well. Plus its cheaper.

  • Just got mine in the mail. Great powerbank, supports super fast charging on my galaxy s20+ or fast charging via usbA.

    I saw a comment somewhere that there is no capacity written on the powerbank but this is false. It's printed on the bottom of the powerbank. A bit hard to see since it's black text on black

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