Maximum Current for 10400

Hello Folks,

I just bought an Anker USB Charger with a maximum output of 2.4Amps per port but after it arrival I read on the back of my battery saying input of 2 Amps. Does this mean the maximum current drawing capability for the battery is 2Amps and not 2.4 Amps? If this is the case then why Anker makes its chargers at 2.4 Amps per port if they are not to fully support their own devices?

You’re confusing the input with the output specs.

The external battery will draw (or pull, or input) a maximum of 2A at ~5v as it’s being charged from the wall charger but will put out (or push or output) a maximum of 2.4A at ~5v. The battery’s output is what really matters here when it comes to charging your devices, not charging the external battery.


Hi and welcome to this community!

The Anker chargers are deliberately designed to offer the maximum charge speed of your device and work across a range of devices include Apple tablets.

There are losses in the ports and cables.

So take an iPad, it is actually capable of ingesting at 2.3A (when it is turned off). To allow for cable power losses, the Anker charge is capable of sending out 2.4A or which 0.1A can be lost in the cable and the iPad is charging at its maximum charge.

Most Android tablets charge in the 1.6A-2.0A range.

Most phones in the 1A-1.3A range.

Hence typically the limiting factor is your device, its ability to ingest power, the limiting factor is not Anker hence Anker will charge at the maximum your device can handle.

A typical Anker portable charger (battery) is input at 2A which is less than 2.4A, but often they output at 2.4A like the chargers.

Make sense?


Hello and thankyou for replying.

Yes it indeed makes sense. I did not think of the loses. So Anker charger would be more suitable than a charger giving rated 2A.

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HI SZak,

Sorry but I am not confusing anything here. I understand we want our phones and tablets to be quickly charged but more than that I want the Anker Powercore to be quickly charged too. Anker Powercores are limited to an input of 2 Amp. If this could be atleast 2.4 which would then be same as Ankers USB wall chargers then I would be able to save time charging the anker batteries. This should be more around 4 Amps so for instance if I give 4 hours to my batteries I can take around 16 hours for my phone at 1Amp (this is again without loses)

Thank you for your answer tho.

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First understand Anker’s challenges: watch this

There are safe upper limits of recharging and discharging Lithium Ion. Also the faster you drive the batteries the hotter they get and the heat accelerates the aging, so that 10400mah would deteriorate to less faster if you try to make the batteries recharge faster and discharge faster. So there is a balance to be struck of safety, performance, warranty.

The more Lithium cells you connect in parallel the more you can drive a little bit of power in/out of more cells and so you can input a greater current through larger Powercore. For example the Powercore+ Mini is 1A input for one 3350mah 18650 Lithium Cell. Lithium Poly can be worked a little harder as in the Powercore Slim 5000 which is 2A input. As you go up in physical size you have 2A input typically with 4 18650 Lithium Ion cells. Once you get to around 8 cells we observe 4A input such as the Powercore 26800 with dual 2A input (4A combined). The Lithium Polymer Powercore II 20000 is also 4A input.

So you can solve this recharge problem in a few different ways:

  • you can buy physically larger Powercore with more cells to give more recharge input Wattage. Examples of this is Powercore 26800, Powercore II 20000, and there are QC and USB-C faster input like the Powercore 26800 PD which is a 15W input. The pro with this approach is it tends to be physically smaller a little in total and tends to be lower cost as the packing shipping is less in total.
  • all that physically larger Powercore are doing is spreading across parallel cells. You can accomplish that basic same by using multiple smaller Powercore. e.g. Two Powercore Slim 5000 being charged at the same time is 10000mah combined and 4A input combined. The advantage is you are basically in total control. You can completely control your own recharge speed by owning multiple, as many as you want and recharge in parallel. You can also handle more long off-grid situations (like camping) where one Powercore can fail but you have multiple. You can be some distance from a wall socket and be using one Powercore where you are sat and be recharging another Powercore in the wall and rotate between. The downside is you end up with a bit more complexity and it tends to end up higher cost.
  • The DC to DC conversion is not 100% efficient, it is a function of the clockspeed of the chips used. Newer chips can run faster for any given heat and so more efficient DC-DC converters. The heat from the electronics add to the heat in the cell and so a more modern electronics is more efficient and so less heat from electronics so in any given size you can work the cells are little harder in a more modern designed Powercore. The 10400 is an older design than say Powercore II 10000. So buy newer Anker products. You then use your older Powercore where speed is less important and carry newer Powercore where what you care about matters more. So for example my regularly used Powercore I carry when traveling is a 10000 and a Slim 5000, combined 15000mah combined 4A recharge and my older Anker Astro 15000 is kept at home for power outages.

What I would not do is ignore the video consequences at the top and do not recommend go seeking out other vendors who are prepared to put you at more risk and make your investment last shorter by driving the cells too hard.


amazing answer. I can not thank you enough for this. This has enlightened me. The answer was very elaborate. I knew there was some technological barrier but did not exactly know what was it but now I am quite aware of it. Thank you once again. Saw the video too.

I was already planning on buying another powercore because I am in love with the two Anker products I have bought and definitely can not go for any other vendor other than Anker. 10400 might be an older tech but it still does not heat up; not a kelvin above room temperature (this is what I feel when I touch it). Also I love the bag that comes with it.

I wanted to buy the 10000 mah with single port owing to its smaller size but they are not available in Pakistan. Amazon etc do not work here and also there is only one dealer who is selling these for a higher price but I still want more of Anker.

If you find time can you please explain how does the QC work and how a USB 3.0 charges faster? can they hold more current at lower resistance?

[quote=“Haider_Ali, post:7, topic:49670, full:true”]
I wanted to buy the 10000 mah with single port owing to its smaller size but they are not available in Pakistan. Amazon etc do not work here and also there is only one dealer who is selling these for a higher price but I still want more of Anker.[/quote]

Within the past week, I have purchased two of the newest PowerCore 10000 units (not the QuickCharge units) for their small size and good capacity-to-size ratio. I’m very pleased with these units, more so than with the two PowerCore 20000 units that I also own as well as the PowerCore 13000 that I bought two weeks ago (seems overly large for it’s capacity-to-size ratio).

Have your tried eBay for your purchases? Anker Direct is also an eBay seller and this is where I make my purchases. Always great service and I get my items within a day or two, a week at the most…but then I am located in SoCal and nearby to the product (going by how fast I get them and where they shipped from). Here’s the link to the PowerCore 10000 from eBay. This is the exact same link I ordered from…it is Anker Direct and not some unknown (to me) seller.

PowerCore 10000 from Anker Direct on eBay

Anker Direct main storefront on eBay

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The 10400 is 4 cells each sharing 2A so each cell is getting 0.5A. The Mini+ is 1 cell with 1A, and so the Mini+ gets noticeably hotter than the 10400. The 10000 would probably get a littler hotter than the 10400 as its 3 cells sharing 2A.

Golly, how to explain QC and USB 3…

This will make sense if you understand the Lithium cell recharge and discharge and then understand DC-DC conversion. Once you understand them then QC will make sense.

Charging Lithium cells:

The recharging of a battery involves forcing electrons into the material, those electrons repel each other (like charges repel) and when there are not many electrons in the cell it is relatively easy to force electrons into the cell. As the cell becomes full with electrons, it becomes increasingly harder to force more electrons into the cells. This is shown as an empty cell has a higher current input and the voltage potential is lower, then as you recharge it, the current has to drop off as the voltage rises. These last 2 sentences is very overly simplifying the physics but did i do that in one paragraph? This simple charge roughly shows the process.

DC-DC conversion:

The issue is USB is a fixed 5V so you then have the issue that the cells need a progressively higher voltage input as they charge, initially lower, then higher. How do you give the cell a varying voltage? How do you take 5V DC input and make initially a 3.7V to the cell and then slowly increase it to 4.2V to the cell? I will (again) over-simplify and show the basic electronics of how you change one voltage into another voltage of DC-DC conversion. Watch this video:

Inside the Anker Powercore there are multiple processes going on. When you recharge the Powercore it is taking 5V 2A input and making a lower voltage higher current in a flat Powercore (say 3.7V 2A) and progressively ends nearly full at 4.2A with a lower Amps. Then it then acts as a charger, it takes the 4.2V initially coming out of the cell and steps it up to 5V and then as the voltage from the cells drops eventually to 3.7V, the electronics step the voltage up to 5V.


The cells inside your mobile phone have the same problem to solve as cells inside Powercore. The mobile phone has a cell usually rated 3.7V, when your phone is flat, the cell in the phone is more able to be recharged faster, a higher current. All that QC does is take a much higher Wattage initially over the USB port and then slowly take less as the phone’s cell becomes fully charger. This leads into lower phone recharge times. But how to do deliver higher Wattage? Do you increase the voltage or the current? If you increase voltage you risk a spark at the phone USB socket, if you increase Amps you risk melting the wire? Hence the phone and and the charger communicate and step the voltage, amps, in an algorithm which is proprietary to QC. Ultimately, however, it is just supplying more energy at the start and less at the end, it is just doing the boost converter role intelligently to the cell.


USB 3 is just the current (3.1) standard of USB and USB-PD with USB 3.1 has cables capable of handing higher voltage and higher current so you can drive more energy through the cable and port without sparks nor the wire melting. Ultimately, USB-PD is superior to QC because QC is about recharging a phone, while USB-PD is about much higher Wattage and high speed data transfer. Due to the proprietary nature of QC, it is hard to merge all of the electronics together in an Anker Powercore. One tends to get 1 QC port and a non-QC port and they share little. That tends to cause a higher cost product and physically larger. The future is more USB 3.1 and USB-PD but it will take time as there are not as many USB-PD devices to cause Anker to sell enough units. That will change through the next couple of years.


Think in regards of your device you buy and their charging needs, together, as an integrated system, of devices, cables, chargers. If you literally only have a phone, then buy the phone you want, it comes with a charger, of some kind of technology. Simple.

If you though have a phone, and tablet, and BT earbuds and portable charger, etc, then it becomes more complicated. What matters to you? Is it cost? Is it speed? Is it weight?


@nigelhealy @SZak2015, Thanks my friends!!! All your replies really helped us a lot!:grin:

Thank you Nigel.Your amazing reply has helped me alot understanding this process. Keep up the good work.


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