Last Updated: August 16th, 2014

There is no such thing as too much battery capacity. When it comes to smartphones and gadgets, the more additional power you can pack for a long day or a short trip the better. That's why we're telling you about this 36% discount on a Limefuel Lite 15,000 mAh Lithium-ion external battery pack. It's down from its regular $55 price on Amazon to $34.99 on StackSocial with free shipping.


Just think about what you could charge with a 15,000 mAh battery. Flagship Android smartphones pack a 3,000 mAh battery on average, so the Limefuel would provide about 5 charges 4 charges (every charger has an efficiency rating that indicates how much juice is lost during the energy transfer process. We've confirmed with Limefuel that the efficiency rating of the Limefuel Lite is 80%). And because this unit has dual-USB ports, with 1A and 2.1A output, you could charge your tablet with it, but also your Bluetooth earphones and speakers, Android Wear watch (with the cradle), MiFi router, and more.

The Limefuel Lite also packs a handy LED flash for those power outages or dark nights, and an LCD screen to show you exactly how much battery you have left and which ports you are using. It measures 5.8 × 2.8 × 0.9 inches and weighs only 12 ounces, making it close to the size of 3 Galaxy S5s stacked on top of each other—not bad!

The deal is available on StackSocial for another 6 days, with free shipping in the continental US. If you still haven't picked up an external battery pack, this might be the perfect time to do so. I know I love my Limefuel Limeade 13,000 mAh battery. I charge it once every couple of weeks, leave it in my gadget drawer, and whenever I'm headed for a hike or an extremely long day, I just pick it up and go. It has been reliably awesome at its job.

Source: StackSocial

Rita El Khoury
Rita is a pharmacist by profession, a geek by passion. Her love story with Android started in 2009 and has been going stronger with every update, device, tip, app, and game. She lives in Lebanon, speaks three languages, and watches a lot of TV series.

  • awaaas

    15000 mAh can only charge roughly 3-4 times for a 3000 mAh gadget if you charging while using the gadget. That's if the charger has 90% effeciency.

    • Jason Lee

      Assuming the efficiency is 90. Anker reports that its 3000 mAh mini charger has a 70% efficiency, which they're proud of.

      • andy_o

        I won't go back to anything other than Anker. Power IQ is amazing.

        • me me

          If you use an external battery to OPERATE a phone, such as during battery-draining gaming, then you get one lot of power loss of battery-electrics-phone, a typical loss is 20% hence for say a 3100mah internal battery if supplied say 4 hour use you'd need an external of 3900mah to double life to 8 hours.

          If you use an external battery to RECHARGE an phone's internal battery then you get TWO lots of power loss, both in the external and internal hence in the example of a 3100mah phone battery you'd need 4900mah extenrnal to do a full recharge.

          Another dimension is the trickle charge, a smaller external battery will ingest a given amount of power slower, e.g. a 5000mah battery will get to 85% i.e. 4250mah charge in say 2 hours but 100% i.e 5000mah in say 3 hours, whilst a larger say 7000mah will get to that same 5000mah not in 3 hours but in 2.4 hours.

          So really should aim for a bigger battery and go for one with 2A input so it ingests power faster.

          The problem is not with the output, but the input.

          • andy_o

            I know you know what you're talking about because you use caps a lot.

    • http://www.androidpolice.com/ Artem Russakovskii

      You're absolutely right, and I've just updated the story with a little note.

  • Kashmieer

    Mi 10400 PowerBank has %93 efficiency. Also, it is 20$. So, Nope.

    • Grayson

      Um, is that supposed to mean something to us? How do you know whether or not all battery packs are around 93% efficient? Maybe 93% is actually crap. I bet this one is 99% efficient!

      • Kashmieer

        Also it looks too ugly. You can do a little google search about the battery tests that users run themselves. Well it fills my N5 4 times. You can do the math.

        • Grayson

          Mi's website says the 10400 PowerBank will recharge an iPhone 5S 4.5 times. The 5S has a 1560 mAh battery. By my calculations, if it were 100% efficient, it would charge an iPhone 5S 6.66 times. 4.5 / 6.66 = 0.675 = 67.5% efficiency. So where is this 93% efficiency coming in? Kind of a meaningless number to me if they just mean 93% efficient internally, and not 93% efficient charging devices.

          • http://www.androidpolice.com/ Artem Russakovskii

            Spot on. See Limefuel's answer below on this page on Mi's numbers.

    • Mattie


    • http://www.androidpolice.com/ Artem Russakovskii
  • Canadian

    Only available in the US

  • http://flavors.me/sabret00the sabret00the

    Why aren't these available on amazon.co.uk?

  • lensgrabber

    I don't *need* this but I want it to replace all my other chargers. Any person smart enough to get Amazon to lower their price I challenge you to make it happen.

  • Vaughn Teegarden

    I really wish manufacturers would include built-in wall plugs for easy recharging. The Newtrent Travelpack+ has this, and it's great. No extra stuff to carry to recharge.

  • me me


    Input: 5V/1A (max)

    Hence takes twice the time to charge than a 2A input.

    • Sorian

      If I remember right, aggressive charging will decrease lifespan which means decreasing maximum capacity after a number of charges.

      • Kidney_Thief

        This is absolutely true. I use lots of rechargeable batteries (we're talking AAs and AAAs, here), and I get much more consistent capacity by charging at 200mAh vs 500mAh.

    • crazyg0od33

      that's just to charge the Limefuel device itself - which I would assume most would do overnight or at a time where they can leave it plugged in. So it doesn't really matter too much IMO

      • me me

        *if* that's how you assume the battery will get used then fine, BUT if you get one which does a faster charge you can make better use of any static time, in the pub, or by power socket in airport or in those situations you are off-grid a long time apart from the odd hour or so.

        I then pair with a dual-USB 2x2A PSU to charge phone+battery as fast as possible.

        It matters to me as my off-grid examples are going for 6 days camping and passing through a power socket say for a pub meal for 3-4 hours.

  • Göran Sävström

    Any recommendations for something similar that can be bought from Europe without loosing to much money on shipping?

  • DJRiful

    Best is Intocircuit Power Castle, I tested it a several time and it's solid as it is. http://www.amazon.ca/Intocircuit-PC11200-11200mAh-External-Battery/dp/B00BB5GR0A

  • Mattie

    debating between an external and just an extra battery for my note 3. Extra battery is much cheaper and I'd only use this a few times per year I think but the external works for everything. Advice?

  • Limefuel

    So I have looked into the MI 10400 claim and here is what I have found.

    First thing: http://www.samsungsdi.com/lithium-ion-battery/power-bank
    They (MI) use the Cylindrical Cell (ICR18650-22F). If you notice in the Nominal Voltage column it says 3.6V to 3.78V. That’s the output voltage of the 18650 battery cells used in the Mi battery pack. When you plug into the USB output port it is 5V. So the battery needs to convert from 3.78V to 5V in order to charge your device. 5V-3.78V = 1.22V difference, 1.22V / 5V =.244. That means there’s a 24.4% loss in voltage conversion. 100% - 24.4% = 75.6% max output.

    We claim 80%+ because:
    We have the best PCB components
    Our cells are higher grade (higher mAh than published)
    Our cells used in the Lite series are actually 2600mAh each, not 2500mAh like we advertise (15,000mAh= 6 cells x 2500mAh) 100mAh / 2600mAh = 3.8%. Because of this 3.8% we can claim a higher rate. 75.6% + 3.8% = 79.4%

    Now what MI is claiming is also true, but it doesn’t apply. They are saying that their 18650 batteries are outputting 93% but it is only at 3.7V, not 5V, which is what you need to charge your smartphone or MP3 player. They are claiming output percentage before voltage conversion. Basically it is a marketing tactic used in order to claim a higher number. Real use is 75%-80% for the MI 10400 Battery Bank.
    If this is the case then by MI standards we (Limefuel) also have a 93% efficiency. I hope I have cleared up some of the concerns for everyone.


    Rafael M.

    • andy_o

      Wait a minute here. You are also not being accurate then. Your battery might be higher capacity than published, but that doesn't matter considering that an 80% number is far more valuable marketing-wise.

      What if another company put an even higher grade battery and published a lower number, then claimed 90+%?

  • Sihan Chen

    Are you worrying the power of your iphone?Don't worry,we have the best external battery !