Got a 6 x 18650 power bank, with 1A and 2A output. But will not charge my tablet.


I got a 5V 2A USB 18650 6 Battery Mobile Power Bank Charger Box for Cell Phone MP3 MP4, of course dirt cheap, just £2.59/pcs.
Today I tested with 6 x 18650 new batteries (of course, they was Ultrafire 5200 mAh gray color batteries, so most likely fake.). They was all charged to 100% (they was all charged to 90% and 4.2V when I got them)

I then tried to charge a phone with both the 1A and 2A port, and it worked fine.
But when I tried to charge my PAD ( ASUS Transformer Pad TF300TG 3G) it will not charge it. The PAD requires either 15V = 1.2A, or 5V = 2A (that what is says on the two chargers I have to the PAD). And my new power bank should create a output of 5V = 2A on the 2A port?

Of course, it’s most likely the cheap power bank there is something wrong with. I’m waiting for better batteries, but to then, can somebody come up with some links/name on good power banks with 4 or 6 (I think I want 6) x 18650 batteries, that actually can charge my PAD?

Try this one,they are original with LG,or Panasonic cells inside

Or if you want to use yours batteries. I have this one and its very good… Just please dont use Ultrafire 5200 mAh !!!

I already have some original power banks that works fine, but want to find a cheap but good diy power bank and put in some of my new batteries I will get the next 30-60 days :D, and if they work good, maybe I will give some away.

And no, will not use Ultrafire or any fire batteries in them.

Have ordered some Soshine E3 Portable Mobile Power Bank now, so will we see how they work with my Sanyo batteries.

You did well, now you can use it like a charger and a power bank also,quality is very good !

Don’t know why, but they sell the same E3 model for 12.98 in the same store…

there are times when a product is discounted to leave at the same old price…

Are the batteries in parallel in the box? If so, then their output would be only ~4.2V. If the tablet actually NEEDS 5V for charging, the ~4.2V output from the battery box may not be sufficient and maybe that’s why it’s not charging the tablet?

They are all in the same direction yes.

This is a new brand power bank I just got my hands on. I purchased it and the smaller pocket size version to replace our NewTrent brand power banks that were getting old. This Jackery Giant+ has been the only power bank that has been able to fully charge my iPad 1st Generation fully from a depleted 5% charge to full. What got me to purchase it was the fact it’s one of the only companies to boast using premium cells. It’s a keeper for me, and the small pocket version was able to charge our iPhone 6 plus from dead to 88%.

Jackery Giant

What I have noticed from building my own power banks and reviewing off-the-shelf ones that different companies send me is that there is no one charging specification that all the devices and power banks use to be compatible.

Some devices will only charge if they detect a “smart” charger and some devices will charge as long as they detect the right voltage/current. Some devices don’t seem to care one way or another. For devices which will not charge with a specific power bank, I have a “charging cable” which I believe is just a micro USB cable with the data pins shorted. About 8 times out of 10 this little cable will make everything start working. But day to day, I just carry the power banks that play well with whatever devices I’m carrying.

1 +
As Racer said many devices (tablets, phones) will not charge if you simply provide 5 volts at 2 Amps. The tablet checks the usb data pins, if it does not see the identification it wants, it will not charge.

The other possibility is that the usb identification does match what your tablet wants but the power bank is just junk. The tablet tries to take 5 volt at 2 Amps but the power banks can’t really provide it, the voltage drops and your tablet rejects the power bank as not suitable.

Richie086, the Jackery Giant sounds nice. The pocket version you have is the single 18650 one, correct? Have you by chance tried it with any android devices?

It’s hard to blame the device manufacturers for their devices being picky about charging. You’re charging a $600 tablet/phone/whatever with a $20 charger, and when your junk charger melts your expensive device, you’re going to send that device back to the manufacturer and expect a new one.


There are some FAQ by folks on Amazon, from what I have read, it will charge an Android device. One such question is below:

*_Does this work with an android?

A: works with anything that has a USB connection for power ie like the iphone charging cable Damian MCCANN answered on June 17, 2015 _*


Saying “it will charge an Android device” doesn’t account for the fact that there are thousands of Android devices out there and not all of them are compatible with chargers and power banks that claim to have a generic compatibility with Android devices. Deductive reasoning will help narrow it down if you try different devices with your power bank and different power banks with your device, in addition to testing different cables.

I fully agree with you.

my asus tf101 is very fussy.i wired a 12v cable up for it.
so dont feel bad that your 5v power bank wont charge it.seems to be a common wart with the whole series.mine wont charge from 5v.

Discovered this today also. I tried to charge with some GP power banks that I have got here in Norway (10400 and 12000 mAh) and it will not charge the pad either. I was sure I charged the pad when I was on two trip in India the last year, but I must have used my travel charger to the pad.

But good to know that is was not a bad power bank or bad batteries then. :smiley:

I wonder if the data pins have the correct charge signature on them

The small charge booster board I designed that shorts the D- and D+ pins together will allow an iPhone or iPad to charge from any 5vdc port (even a charging downstream port vs a dedicated charge port) because it tricks the device into thinking it is on a “charger” device rather than a computer…albeit at a 5W or 1A rate, but they will charge

This is my DCP enumerator board

A little info on the charge capability/power capability of USB

They have power banks with smart DCP now. Only kind I would get.
RAVPower 3000mAh Power Bank - 2nd Gen Luster Mini Scroll down and you’ll see the other models they have, most do well over 2 amps.
Anker also sells several models of smart DCP power banks