Aili 4 Cell combo mini-flashlight and power bank - ? up voltage levels after charge?

DonJuane

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Last week I purchased two of the exact same model Aili black/white 4-cell capacity (batteries connect in parallel) Power Banks (logo has "i" in the name Aili a graphic of a battery). This is the one with a small single flash-light (LED) bulb in the center of the top side, and on each side of the LED it has 2 normal USB outputs and the micro-USB charging input. On the right side facing the logo is a slide switch with settings for .5A, 1A or 2A output. The unit came without batteries so I randomly purchased several online, including a set of red Ultrafires (4000ma) and blue Ultrafires (5000ma). Along with one set of batteries came a 2-cell charger labeled "Video/Digital Camera TRAVEL CHARGER", Product name: Charger, Input AC 100V-240V ... Output DC 4.2V 650mA.

Now I tried to understand what kind of batteries to use here. Both sets of Ultrafires I purchased on eBay had no advertisement regarding them being protected or not but upon arrival and inspection they both turned out to have the button on the bottom and "hot" wire clearly going from the top of the 18650 down to the button. I then researched at every place selling this Power Bank online for more specifications but the info was very sparse. One site said "use unprotected batteries - protection is in power bank". I finally got an answer back from my Chinese vendor and he said "use unprotected" with no further explanation. I saw another vendor selling the same supply who warned that using protected batteries would damage the unit because it would confuse the protection circuitry.

So onward I went with testing the unit. In my opinion, when batteries are wired across a parallel strip, I would assume that should one "go down" - they all could potentially suffer and at a dangerous level, for example if one of them ever shorted it would take the rest of the bunch down with whatever damage the one getting shorted displayed, times a power of 4. A little scary ..... So I decided to forgo the warnings and since I didn't pay that much for the power bank, plus the length of the Ultrafire protected style battery was not too long to fit into this bank, I began charging the batteries which has arrived and continued with a stableized voltage of 3.91V. During the charge cycle, I continued to monitor the voltage levels and the temperature of the batteries as I charged the bank with a 5V 2A wall charger. I did not measure the amp output of the wall charger but knew it was close to 2A because it had no problem fully charging an iPad. I put a full charge on the blue Ultrafire 5000mA batteries while monitoring voltage and temperature. The temp never rose much above room temp but the voltage only climbed up to 4.07V before it topped out. I waited 24 hours with the device still charging and the charge still would not increase past 4.07V. Just in case I had a problem with this setup, I initialized my other Power Bank with another set of batteries and checked them to find after 24 hours, the voltage only rose to 4.09V. Curious if the batteries were bad, I plugged them in the no-name 2 cell AC wall-charger (I have 2 of these 2-cell charges, charged them a couple of more hours and the DMV reading went up to 4.21V - a "happy voltage" I was hoping from from the Power Bank charge but never saw.

Now my question here would be, does anyone think that if I rip the regulator button off the end of 4 of the Ultrafires, that the Aili charger might be able to zip them up 4.20V charge I am looking for, resultant of there being no protector in the circuit? I am not that nervous about the Aili being void of its own protection circuit since everyone selling it has said it does, but my concern would be having 4 unprotected cells in parallel and what happens should one of them decide to go down the road of no return and my exposure to the rest following suit. Another reason I am asking this before conducting the test is I had to trash 4 cells if the top charge from this device is still going to hover around 4.07V.

I have run through now 2 complete cycles of charging and discharging the Aili and the results and voltages are near exactly the same. From a 4.09V pseudo full-charge, I was able to power a setup of a small router and air-card that draws 1A for a period of 8 hours before the Aili shut itself off due to low battery voltage. The voltage level of the cells was observed at 3.21V when this happened.

I have currently removed the batteries from the Aili, and charged them up to 4.21V in the external wall chargers I have. I am now running a test to see how long the 1A load will continue to be powered when the starting voltage was at 4.21V instead of the Aili full charge value of 4.09V.
 
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ChrisGarrett

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Get rid of the UltraFire cells and replace them with quality versions, like those from Panasonic, Samsung, Sanyo, Sony or LG. You might not be able to fit protected cells in there, so maybe an IMR chemistry, or the newer hybrids from Panasonic: NCR18650PF would work?

Chris
 

DonJuane

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Well I just concluded my test with a battery bank of blue Ultrafires charged up to the full 4.21V using a wall charger instead of the Aili internal charger (which only makes it up to 4.02V). The 1A load ran 9hrs this time before the unit shut down. In the test prior to this one, where the toped-out charge provided by the Aili was only 4.02V, the Aili unit under a 1A constant load had lasted 8hrs before the unit shut down.

I decided to strip open the plastic of the blue Ultrafires (rated at 5000mA eache - he, he) with the thought of removing the circuit protection button and re-running the test. On closer inspection, however, the wrapper stated that the battery included "over discharge protection" only. Now I suppose this could be anything from a fuse to an elaborate circuit but I assume the former because there was no "button" circuit board on the top or bottom. This was my mistake as I was assuming the plastic seam was the feed wire from the + down to the button and another illusion made of a ring around the bottom actually didn't exist when I removed the blue plastic wrapper. It was simply plain battery under there (with something perhaps stamped in the top to keep over-current situations from occuring) So the removal of any circuit button test was abandoned because none existed on this model of the blue jacket 5000mA labeled Ultrafire battery.

I did measure the voltage across the terminals of the Aili battery buss with the charger plugged in and no battery attached and the voltage read 4.6V. So I am just not certain why none of the batteries will be brought up while charging to a value over 4.02V. Again I proved that it is not necessarily the fault of the battery because all 4 of the blue Ultrafiers can be quickly charged to 4.21V by charging them in an external wall charger. I assume that with the Aili charging, the current just sinks to 0 at around 4.02V because the battery-less voltage at 4.6V is certainly high enough there to bring them up to where they need to be.

So right now just for grins I am starting the test again with the red Ultrafires, to see if the results are the same and will report back.

P.S. I appreciate the suggestion on the Panasonics but the lowest price I found on them was $9 and up, so with 4 of them in the battery pack, I am way over budget for what I was trying to create with this power bank.

P.P.S. But before I go, let's check out the real performance of these blue Ultrafires. It looks like from my calculations, that the 4 x 5000mA rated current would give 20A hours of potential current in ampere hours. If you calculate that at 20A x 3.8V (average battery voltage) - that would be 76W of power from the four if the battery Ah rating is accurate. Once going through the up-converter to produce 5V, you would have 76W / 5V = 15.2A (hours) of potential current on the output, so assuming a 85% efficiency factor of the voltage up-converter, that would turn out to be potentially 12.9Ah at 5V.

Now since my Aili powered a 1A device for 9hsr before shutting down (when the battery was charged externally and the starting voltage was 4.21V), that would mean the real Ah value of this battery bank was a maximum of 9Ah instead of 20Ah, which is just simply a number I am throwing out that one might guess if no other factors were considered). Now to calculate what the real value of the Ah of these blue Ultrafires, we would do this. We know the true Ah value to be 9Ah and the bragging point of the Ultrafire whould have been at best rated at 12.9A once the current travels through "the works" of the Aili. This would be calculated as 9Ah/12.9Ah = 70% of their their stamped value - or instead of their stamped value of 5000mA, we can instead assume a rating 3500mA, which I suppose is not as big of a fib as one might expect and still a good amount to power from the bank for general use. We'll also assume that the effective power of the blue Ultrafires is only around 3111mA if we consider that the Aili is incapability of fully charging at least the blue Ultrafire to provide its full potential (about 8hrs at 1A load). But at this point I am believing it is not battery related. Should I ever find some better quality batteries, I'll give them a run through the test gauntlet, but I am sort of guessing I may not see an improvement, while still I am willing to accept this level of performance for now from batteries that cost ~ $1.25 each.

Your mileage may vary :)
 

ChrisGarrett

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You do realize that there are no 5000mAh, nor 4000mAh 18650s on the face of Planet Earth, don't you?

The best we're at right now, that you can buy regularly is the Panasonic NCR18650B at 3400mAh. There are some Panasonic NCR18650G 3600mAh cells floating around, but they're as rare as hen's teeth.

Look for HKJ's test of the blue TrustFire 18650, which he actually disassembles. I think that he got 1000mAh out of his test samples, lol.

If you have to go cheap on something, go cheap on beer, or toilet paper, not on anything that has to do with lithium ion cells, or chargers, is my suggestion.

Good luck in your testing, however!

Chris
 

DonJuane

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Well I had a strong feeling they weren't up to their advertized value, thus why I was experimenting with them. Let's just hope they're also wrong on being labeled an "Ultra-FIRE!!!!" :)
 

DonJuane

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Well had I found the following site before, I could have saved myself about 2 full days of work!

http://lygte-info.dk/review/batteries2012/Common18650IndividualTest%20UK.html

I did notice that the "3000aH" red UltraFires I ordered weigh about 0.1 oz more than the "5000aH" blue UtraFires. According to the battery testing in the URL above, the reds show to actually be 2600 aH which is nearly 3x that of the higher-rated B.S. 5000aH label covering the blue. So for the most part, at least compared to all the blues, the reds far outpace them regardless of the label specs.
 

DonJuane

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I have finally concluded my testing on this unit. I ran the Red and Silver UltraFires through the cycle twice and they power the 1A test load for about 12 hours. This is with the top charging voltage having reached a value of only 4.11V as opposed to 4.09V when I tested the blue UltraFires, both top charging voltages reached being below the potential full-power play-back of 4.2V. For this reason (the Aili not charging the batteries all the way up to 4.2V) I am calling this unit not an optimum performer. Charging the batteries to 4.2V in an external wall charger will produce about 8% more life out of the charge than did the lower level attained by the Aili natively, but it's probably not worth the effort.

So if you are looking for a dirt-cheap way to charge or power a 1A iPhone, 2A iPad or equivalent device for a good amount of time while using dirt-cheap batteries and a relatively inexpensive device, this may be what you are looking for. From one of the worst batteries referenced here, the blue-cased UltraFire, there was still 8hrs of 1A current provided by this device. Upping to a set pf 4 red-cased UltraFire, there was about 12hrs of 1A current from this device. So with a little patience and with a great deal of shopping skills you probably can get the whole set up of an Aili and set of 4 batteries for around $15.

For a significantly larger investment battery-wise, you could realize quite a longer amount of power (ampere/hours) than I found from these low-quality batteries, perhaps even up to double what I found in my own tests with these bottom of the line offerings off "the bay". Still there is the issue with the low voltage of 4.10V considered by the internal control unit of the Aili to be a full-charge, which knocks down any chosen 18650 battery's life by up to 10%, perhaps enough to discourage anyone but the most casual user of this device.

So hopefully this will answer other's questions on this unit and give you a better starting point than I had .... My unit now gets tossed into my backpack for my next long hike or camping trip. Until then I will take the precaution of removing the batteries for storage since they are all wired in parallel and even the slightest difference in voltage between any in the group can cause them all to run down prematurely, or else do something a lot worse. Following along with the design of this unit by adding the suggested unprotected cells in parallel (seems to work with either protected/non I found) and combining those with the Aili's not quite optimum charging voltage, at least the two of these units I tested (with the exact same charging top-out voltage) appear "not quite ready for prime time". Still until a better design comes along for a good cheap price like these babies, I am thinking lugging them along seems like a better idea than getting stuck in a remote location and finding your device is dead with no alternative power source.

Enjoy!

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NOTE: Press and hold in a few seconds to start the power down cycle.


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Update 2014-5-23: Add text "press and hold to start power down sequence"
 
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DonJuane

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Update: I contacted the vendor selling these to report my findings. Here is his response:

I am so sorry but the Technical staff said the performance is normal and there is +/- 0.1 v deviation, it is within the normal range, the Chip set, if the voltage is too large , for some battery it will not bear and will get burned
i am just a re-seller and i don't quite understand but i have sold lots of the items you are the first one who response this.

I don't agree that this voltage is within tolerance. I do agree that I could be the first one to bring issue up because I am certain a lot of people don't concern themselves with such matters. Still if you don't mind the slight shorting of a charge cycle or if you want to charge the battery in an external charger for those times when a maximum output time is needed for an emergency, then this makes a great power pack.
 

Fleder-Maus

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Feb 13, 2014
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Hey all,

i also bought this powerbank. I filled it with 4 x Samsung INR18650 29E - 2900mAh 3,7V.

Now my question:

I´m just loading it via Mini USB. When the 100% LED is flashing (ON/OFF/ON/OFF ....... green) does it mean it is FINISHED or does it mean it´s busy with getting it from 75% to 100 % ?

I´m just wondering because it´s flashing for some hours now :thinking:

THX for help!
 

Gauss163

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HKJ's review shows premature charge termination - charge 4 cells as workaound.

@Don This unit has been reviewed by HKJ. His tests show that it uses a nonstandard charge algorithm, with the detriment that it does not fully charge (when charging 1 or 2 cells) because it terminates at too high current (450mA). As a consequence, the fewer cells charged the more premature the termination, e.g. one cell terminates at 450mA, but 4 cells terminates at 450/4 = 112mA/cell. Indeed, the graphs at the end show that a single cell drops from 4.20 to 4.11V at termination, but 4 cells drop only to 4.17V. So a workaround is to charge cells 3 or 4 at a time to get lower termination currents, so fuller charges.
 
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