Making a usb charger via AA batteries... - Galaxy S II Accessories

Hello,
I read in a forum that someone made an usb charger via 4 AA batteries (1.2V) and it was plain simple as a scheme. He said that Samsung S2 takes care of the voltage. The microusb needs 5V - 0.5. The 4 pills go 4 x1.2 = 4.8V. So it is fine in the beggining. When the voltage of 4 pills during the charge goes down to 4.2 V, then the Galaxy S2 stops taking charge. In this way no damage is made.
Any one made such a charger? What are your thoughts...
Regards,
albsat

Note that the 1.2V figure is for rechargable AA's (NiCd or NiMH cells) -- an alkaline cell would put out 1.5V. Wiring 4 alkaline AA cells in series would put out 6V, which could fry something.

yes it is correct. I meant 4 AA rechargable pills. Although the micro USB port cann't give more than 5V oultput.

albsat said:
Hello,
I read in a forum that someone made an usb charger via 4 AA batteries (1.2V) and it was plain simple as a scheme. He said that Samsung S2 takes care of the voltage. The microusb needs 5V - 0.5. The 4 pills go 4 x1.2 = 4.8V. So it is fine in the beggining. When the voltage of 4 pills during the charge goes down to 4.2 V, then the Galaxy S2 stops taking charge. In this way no damage is made.
Any one made such a charger? What are your thoughts...
Regards,
albsat
Click to expand...
Click to collapse
I dont think you should try that! In case you want a burnt SGS2 :O

I have a solar powered battery pack. It takes 4 rechargable AA batteries, and can be charged by a USB-in port as well as the solar cells, and outputs 5V on a USB port. I use it on long bike rides when the GPS eats up the battery.
The thing cost me £15 from maplin, and carries very little risk of frying my £500 phone. The benefits of not frying my phone far outweigh the cost.

i've bought this one.
http://www.ebay.de/itm/AA-Battery-E...310375?pt=PDA_Accessories&hash=item56468505e7
not too expensive, so i didt have to waste my time with making one on my own.

Related

Anything special about the USB cable included in box?

I just got my S2 5 days ago. All this time I been wondering why it takes around 5 hours to charge from 20% to 100%. At first, I been using my G2X charger, it was rated at the same 5V 1A output so I thought it wouldn't matter. Then I used the included Samsung charger with same LG cable, no difference. Now when using the Samsung cable, it only takes about 2 hours to charge from around 15% to 100%.
Is this just coincidence? Is my phone too new and just needed a few cycles? I'll test again tomorrow, or when my phone reaches below 20% with the LG cable.
There's been known issues with using chargers other than stock..mine gets stuck at 100% until I reboot if I use any charger other than the OEM that came with it.
Sent from my SGH-T989 using XDA
the OEM cable
it'll be your life line in case of emergency like this one
http://forum.xda-developers.com/showthread.php?t=1561432
From my experience you're going to always want to use the charger and cord that came with the phone. I bought my Galaxy S II off the streets and it did not come with the cord, so originally I tried using my OG Droid charger since it's micro USB too but it wouldn't even accept it at all (I'm pretty sure because it was too under-powered for the Galaxy S II (My speculation)). I tried using an older LG micro USB cable too (I think it was even older though) it didn't work either, so now I use my Vizio TAB micro USB cord which seems to work fine.
But also at my work we have a 3rd party micro usb charger too but it's universal, but if I charge my phone on there, not only does it take longer to charge it doesn't hold the battery as long.
So what I've figured out is you're gonna want to use your own charger the phone came with to achieve maximum battery life, also unplug the charger right away when it hits 100%.
shilent said:
I just got my S2 5 days ago. All this time I been wondering why it takes around 5 hours to charge from 20% to 100%. At first, I been using my G2X charger, it was rated at the same 5V 1A output so I thought it wouldn't matter. Then I used the included Samsung charger with same LG cable, no difference. Now when using the Samsung cable, it only takes about 2 hours to charge from around 15% to 100%.
Is this just coincidence? Is my phone too new and just needed a few cycles? I'll test again tomorrow, or when my phone reaches below 20% with the LG cable.
Click to expand...
Click to collapse
Wow lol I post the same thing every second day on some forum or other xD
The usb is special in the sense it has a nice rubber feel and cool plastic iphone style caps on the end..
Its a MICRO-USB male to USB male cable, nothing more, seeing as it is still a standard USB cable it has a max current of 5v (5.25 I do believe..), plugging it into a USB to AC converter over 5v can screw up the device and cable, sscond point.
Standard charger is 5v AC, using a charger below wont cause harm, but using one above can screw up your phone and battery and not ground it properly..
3rd point, keep in mind the mAh on the charger when charging, some (for like bluetooth headsets) are only 500mAh)
mAh is an acronym for ampere an hour, and in short, for chargers measures the current sent to the device at an hourly rate, for batterys (such as lithium ion) measures the actual charge capacity of the cell, using one with a higher mAh then the stock battery (1850mAh) will only charge it quicker and is recommended.
Fourth and final, remember with USB to AC adapters that some only have +5 and ground enabled (2 outer pins), ising the device its meant for on a ac adapter with all 4 pins enabled will make the device try to establish a connection and can again, make it not ground properly. I think ours has the 4 pins enabled though so ignore the last point..
*edit
Lmfao at above few posts (your theories have no basis, allow me to explain)
When you plug your charger in, regardless if its connected or not, its "live"
That being said, the every cellphone (keyword: cell) uses a lithium-ion battery,
That cell has a control board with a chip with a bit of information, some variable, the device has READ access to this board, and collects informagion such as max mAh, current mAh, and min mAh, the device then calculates from that, a percentage,
It then displays that information to the user, the minimum (displays 0-1%), is usually a value around ~100mAh if the cell dies to 0mAh, this can reset the control board and drasticly reduce the batterys expectancy and overall life.
Also, the actual chip on the phone, is simply for, when the battery is full, (current mAh meets max)
Said device drops connection to the cell and resumes on AC, leaving battery fully charged.
Unless you use a charger outside above said specifications, its literally impossible for a charger or file on said device (referring to batterystats n00bs who dont research) to adjust or recalibrate a lithium ion battery.
Hows that for a response I kept it clean
doug36 said:
Wow lol I post the same thing every second day on some forum or other xD
The usb is special in the sense it has a nice rubber feel and cool plastic iphone style caps on the end..
Its a MICRO-USB male to USB male cable, nothing more, seeing as it is still a standard USB cable it has a max current of 5v (5.25 I do believe..), plugging it into a USB to AC converter over 5v can screw up the device and cable, sscond point.
Standard charger is 5v AC, using a charger below wont cause harm, but using one above can screw up your phone and battery and not ground it properly..
3rd point, keep in mind the mAh on the charger when charging, some (for like bluetooth headsets) are only 500mAh)
mAh is an acronym for ampere an hour, and in short, for chargers measures the current sent to the device at an hourly rate, for batterys (such as lithium ion) measures the actual charge capacity of the cell, using one with a higher mAh then the stock battery (1850mAh) will only charge it quicker and is recommended.
Fourth and final, remember with USB to AC adapters that some only have +5 and ground enabled (2 outer pins), ising the device its meant for on a ac adapter with all 4 pins enabled will make the device try to establish a connection and can again, make it not ground properly. I think ours has the 4 pins enabled though so ignore the last point..
*edit
Lmfao at above few posts (your theories have no basis, allow me to explain)
When you plug your charger in, regardless if its connected or not, its "live"
That being said, the every cellphone (keyword: cell) uses a lithium-ion battery,
That cell has a control board with a chip with a bit of information, some variable, the device has READ access to this board, and collects informagion such as max mAh, current mAh, and min mAh, the device then calculates from that, a percentage,
It then displays that information to the user, the minimum (displays 0-1%), is usually a value around ~100mAh if the cell dies to 0mAh, this can reset the control board and drasticly reduce the batterys expectancy and overall life.
Also, the actual chip on the phone, is simply for, when the battery is full, (current mAh meets max)
Said device drops connection to the cell and resumes on AC, leaving battery fully charged.
Unless you use a charger outside above said specifications, its literally impossible for a charger or file on said device (referring to batterystats n00bs who dont research) to adjust or recalibrate a lithium ion battery.
Hows that for a response I kept it clean
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Click to collapse
That's exactly my point. Shouldn't all micro USB cables be the same? I been charging all my other smartphones with many different micro USB cables and they all charged normally. Now with this phone, it takes over 5 hours to charge with my LG branded cable, this is with the stock S2 charger. Now with the Stock S2 cable, it charges in about 2 hours.
I'm gonna have to test again with the LG cable, as others reported long charging times within the first few days.
BTW, the current rating on a charger is NOT the hourly rate (ah). Also charging a lithium ion battery at a rate of 1850mah or higher should not be recommended.
Sent from my SGH-T989 using XDA
shilent said:
That's exactly my point. Shouldn't all micro USB cables be the same? I been charging all my other smartphones with many different micro USB cables and they all charged normally. Now with this phone, it takes over 5 hours to charge with my LG branded cable, this is with the stock S2 charger. Now with the Stock S2 cable, it charges in about 2 hours.
I'm gonna have to test again with the LG cable, as others reported long charging times within the first few days.
Sent from my SGH-T989 using XDA
Click to expand...
Click to collapse
Its never gonna be a linear charge or drain.
Simply put its an OS, As all OS's they have services that can start at different points, and also open different apps, also using rhe device, applications still in the ram, connection strength will all effect this its impossible to check 2 differenf charge methods accurately enough to get a definitive answer without 2 identical systems, apps, data, kernal and all, one on top of the other, plugged in simultaneously, in sleep mode, to the same outlet :/
Haha well I may be in trouble. I use several different friends, co workers chargers everyday.
Sent from my SGH-T989 using xda premium
JaZart said:
Haha well I may be in trouble. I use several different friends, co workers chargers everyday.
Sent from my SGH-T989 using xda premium
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Click to collapse
I have 3 chargers I use for this and haven't had no issues, there is no way using a different charger (unless its outside above said specifications) that it can do anything to your device including screw with the charge level.. people just don't like to research.
Just an update, it took 2 hours and 25 minutes to charge my S2 from 25% to 75% using my LG cable (same stock S2 charger). I'm gonna test with my Palm micro USB cable next.
shilent said:
Just an update, it took 2 hours and 25 minutes to charge my S2 from 25% to 75% using my LG cable (same stock S2 charger). I'm gonna test with my Palm micro USB cable next.
Click to expand...
Click to collapse
One, if you want an accurate trst with one device, kill to zero percent and plug it in, eithout turning on time to 100%, run same test eith another cable
**EDIT
shilent said:
BTW, the current rating on a charger is NOT the hourly rate (ah). Also charging a lithium ion battery at a rate of 1850mah or higher should not be recommended.
Sent from my SGH-T989 using XDA
Click to expand...
Click to collapse
http://en.m.wikipedia.org/wiki/Ampere-hour
Link for you to check your **** before correcting people
Using one equal to or higher then battery capacity IS recommended..
To save you the trouble of reading **** WAY over your head:
The Faraday constant is the charge on one mole of electrons;
approximately equal to 26.8 ampere-hours. It is used in
electrochemical calculations.
An ampere-hour is not a unit of energy. In a battery system, for
example, accurate calculation of the energy delivered requires
integration of the power delivered (product of instantaneous
voltage and instantaneous current) over the discharge interval.
Generally, the battery voltage varies during discharge; an average
value may be used to approximate the integration of power. [3]
In summary, the higher the mAh, the longer the battery will last.
One, if you want an accurate trst with one device, kill to zero percent and plug it in, eithout turning on time to 100%, run same test eith another cable
**EDIT
http://en.m.wikipedia.org/wiki/Ampere-hour
Link for you to check your **** before correcting people
Using one equal to or higher then battery capacity IS recommended..
To save you the trouble of reading **** WAY over your head:
The Faraday constant is the charge on one mole electrons;
approximately equal to 26.8 ampere-hours. It is used in
electrochemical calculations
An ampere-hour is not a unit of energy. In a battery system, for
example, accurate calculation of the energy delivered requires
integration of the power delivered (product of instantaneous
voltage and instantaneous current) over the discharge interval.
Generally, the battery voltage varies during discharge; an average
value may be used to approximate the integration of power. [3]
In summary, the higher the mAh, the longer the battery will last.
For chargers, the higher mAh sends a larger current of the same voltage to the device, charging it faster, lower mAh can and will cjarge slowly.. I'm not sayin go use a 5v 50k mAh charger for the battery and charge it in a split second here.
Wtc! I hit edit! Mod plz merge these...
Charge rate of 1C = the capacity of the battery, in our case, 1C = 1850mah. It is not recommended to charge over 0.7C when it comes to lithium ion batteries. If a charge rate of 1850ma is recommended, then why do all chargers top out at 1A?
I collect high performance flashlights, most of them use lithium ion cells. I know about charging and discharging li-ion otherwise I could lose my hands.
Anyway, the point of this thread was about the stock USB cable vs other cables. The only thing I can think of at the moment is that my LG cable has more resistance than the Samsung cable, which is why it charges slower. Though that's hard to believe is the charging time is more than double.
doug36: I've seen you post in other threads, all you like to do is insult people, or at least try to. This is the last time I'm gonna post in this thread, you keep posting irrelevant information. Next, you're going to try to insult me, I'm not going to respond, and you're going to think you won or whatever, I don't care.
If anyone wants more info, or has any questions, please send me a PM.
JaZart said:
Haha well I may be in trouble. I use several different friends, co workers chargers everyday.
Sent from my SGH-T989 using xda premium
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Click to collapse
Eww... everyone hits and quits it? XD
I've noticed that the charger that comes with the S2 has a special hook on one side and looks distinctly different than other usb micro cables.
Personally i think it's really dumb.. wasn't the point of micro Usb to be uniform across all phones?!
Sounds like a good way for Samsung to make some extra bucks.
JhonKa said:
I've noticed that the charger that comes with the S2 has a special hook on one side and looks distinctly different than other usb micro cables.
Personally i think it's really dumb.. wasn't the point of micro Usb to be uniform across all phones?!
Sounds like a good way for Samsung to make some extra bucks.
Click to expand...
Click to collapse
I was curious about this two. What makes the included charger official...the brick or the cable out both
Sent from my SGH-T989 using xda premium
I have no idea, all I know is that i tried to use my charger for my G2X and the SGSII wouldn't go past 95% charged? I used the Samsung charger and it charges perfectly?
Well lately my stock samsung charger has been terrible.
Even when I plug it into the wall it charges so slowly that if im below 15%; it will die
When left alone or charging while off for about 45min it will have up about 2-5%; so there's a major problem here.
But using a different charger and it charges at a faster(normal pace); 5% to 65% in appox 1 hour.
JaZart said:
Well lately my stock samsung charger has been terrible.
Even when I plug it into the wall it charges so slowly that if im below 15%; it will die
When left alone or charging while off for about 45min it will have up about 2-5%; so there's a major problem here.
But using a different charger and it charges at a faster(normal pace); 5% to 65% in appox 1 hour.
Click to expand...
Click to collapse
That's normal? :O mine takes about 4 hours from red battery.
Sent from my SGH-T989 using xda premium
Has anyone noticed that if you turn the phone off..or let the battery die to 0% and then turn itself off. If you then plug it into an LG usb cable it will put the phone into download mode.
This works every single time with my g2x cable.
Sent from my SGH-T989 using Tapatalk

Solar charger

Does anybody know of an existing solar charger with the amperage to charge the Galaxy tab?
fjl307 said:
Does anybody know of an existing solar charger with the amperage to charge the Galaxy tab?
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Click to collapse
I have not seen a non-professional grade solar charger that can crank out the 2 amps, needed to get your Tab charged in a reasonable time. You can, if you disable the power-requirement option (see other threads for this), trickle load the Tab to keep it more or less topped up, but unless you are willing to go for a professional (i.e. expensive) solar unit I, for now, do not see a real valid solution.
But hey, I'm only putting my own $0.02 here. I hope somebody can correct me and mention/suggest a good solution here... Hoping.
theoretically
5v x 2A / 75% efficiency = 13.3 w of solar cell . I suppose a 15w solar cell would provide the charge current in full sun. but thats expensive kit for charging your Tab
Excellent device
If u mean the solar power bank charging for phone, it must exist. I have ever seen that.
samsung battery and samsung charger
samsung battery and samsung charger parts for laptops on cbattery.net
Im using solargorilla with a Powergorilla as a battery, so the panel charges the gorilla and then im charging the device from the gorilla.
Have used it to charge my dell laptop, my p7500 & my s3 without any problems.
Sometimes if i only charges my phone or my tab i don`t use the gorilla, so it can charge the p7500 by itself without a problem.
Since i never has an answere to people befor now i cant post links, but you will find both devices on: www powertraveller com
Hope that helps you
Sent from my GT-P7500 using xda app-developers app
with such a growing technology and sudden inventions, such charger is very possible to be existing, if not, it's not far from being developed, by the way I have not seen it by my self...
tommygHTCdream said:
5v x 2A / 75% efficiency = 13.3 w of solar cell . I suppose a 15w solar cell would provide the charge current in full sun. but thats expensive kit for charging your Tab
Click to expand...
Click to collapse
Yeah its cheaper to use amasing 10 buck car charger
You can purchase a 10 watt panel ($25)on ebay- I bought an ecoworthy model, getting about 15 watts under peak sun. Then feed the panel to a voltage regulator ($5 eBay - step down regulator, has USB port for output & pinouts). That would charge directly from sun.
Best setup is an inline battery (you can use any voltage and using the same regulator to charge - read up on proper voltage charge rates) That way excess power is stored so your charge doesn't fluctuate with sun conditions.
Sent from my SAMSUNG-SGH-T989 using xda app-developers app

1A or 2.1 A?

So, I have powerbank and I have 2 ways of charging: 1A and 2.1A. which one to use when charging my note 2?
Handwritten from my Note 2
Depends on the cable you'd use. Samsung cable will go near 2amp, generic ones do about 1 amp
kebabs said:
Depends on the cable you'd use. Samsung cable will go near 2amp, generic ones do about 1 amp
Click to expand...
Click to collapse
I have samsung cable.. So is it smart to charge via 2.1 A ? Can it do some damage on the phone ?
I have a Momax external battery and have charged the phone with the 2.1A port. It didn't heat up, it didn't have any problems. I was planning on measuring the exact amperage that comes out of the samsung charger and the momax battery (iPower Pro), but I didn't get around to it, because I suspect the difference is actually smaller. There are many people who used more powerful chargers to charge their phones faster, and the only thing that degraded was the battery lifespan, but the difference in those cases was upwards of 0.5A between the original and the new charger. I find the 0.1A to be a small difference and I have no problem using the 2.1A port on the iPower.
So to answer your question, no, it won't damage your phone. Theoretically it damages your phone's battery, but it degrades anyway due to charging cycles, so you won't notice any damage caused by the extra 0.1A unless you plan on still using the note 2 10 years from now.
sandulea said:
I have a Momax external battery and have charged the phone with the 2.1A port. It didn't heat up, it didn't have any problems. I was planning on measuring the exact amperage that comes out of the samsung charger and the momax battery (iPower Pro), but I didn't get around to it, because I suspect the difference is actually smaller. There are many people who used more powerful chargers to charge their phones faster, and the only thing that degraded was the battery lifespan, but the difference in those cases was upwards of 0.5A between the original and the new charger. I find the 0.1A to be a small difference and I have no problem using the 2.1A port on the iPower.
So to answer your question, no, it won't damage your phone. Theoretically it damages your phone's battery, but it degrades anyway due to charging cycles, so you won't notice any damage caused by the extra 0.1A unless you plan on still using the note 2 10 years from now.
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Click to collapse
Thanks for reply mate ! I was thinking the same, but i needed some sort of confirmation tho
Use the 2.1A one.
The phone should only draw 2A from it anyway, that just means the port is capable of supplying 2.1A.
Using the 1A port will just charge your phone slowly, the 2.1A port should charge it as quick as the official charger, depending on which cable you use.
It is a matter of supply and demand. All USB devices can safely be plugged into any USB charger. Given an unlimited amount of current available from the charger, each device will still only draw only as much current as it is designed to draw. If the charger is rated 2.1 Amps or 5 Amps or 10 Amps, a 1.5 Amp device will still only draw 1.5 Amps. The charge rate will be at maximum Think of it like your house wiring. The circuit may have a 20 Amp circuit breaker in the basement but we plug in 40 Watt bulbs and 100 Watt bulbs and TVs and electric shavers that all draw different amounts of current. The 100 Watt bulb uses less than an amp but is unharmed being plugged into a 20 Amp receptacle (charger). Now we come to the flip side. If the charger Is rated lower than the device it just charges slower than it would if the charger could supply at least as much as the device uses. To go back to our example, the 1.5 Amp device plugged into a 1 Amp charger will take longer to charge that it would with a charger rated 1.5 Amps or higher. My analogy has one hole. If the stuff plugged into the house receptacles exceeds 20 Amps the circuit breaker pops. This will not happen with USB chargers as they limit the current and will not try to supply more than they are rated for. Stick to chargers rated as high as the one that came with your device or higher and you will be fine

Can our phones charge safely from a 6V USB charger?

Like the title says, can the typical smartphone (I'm actually asking for Galaxy Nexus specifically) safely charge from a 6V USB charger?
I'm asking because I want to make an Altoids portable USB charger for my GNex during travels. I've Googled a few results with mixed results. Some people built such a charger with a 4-AA battery setup, which means there will be 6V in the circuitry. However, some people have added a 5V regulator to the setup, while some have not. Those that have added it, sometimes reported insufficient voltage to charge the phone.
Basically, do I need the 5V regulator to safely charge my phone in this particular setup?
I know I can buy such a charger that is mass produced, but I want the satisfaction of a DIY product and appear to be the coolest hipster geek with my Altoid charger
Use Ni-MH rechargeable battery. Their voltage is 1.2V each, resulting in 4.8V in total.
If you use 4 Ni-MH battery with 5V regulator, it won't work. Voltage regulators are only good for stepping down, otherwise there will be improper operation.
I never understood portable chargers...with no disrespect to the OP, why wouldnt you just buy another battery or two? They are smaller and easier to travel around with than a portable charger without the voltage risk of running out of spec.
tincbtrar said:
I never understood portable chargers...with no disrespect to the OP, why wouldnt you just buy another battery or two? They are smaller and easier to travel around with than a portable charger without the voltage risk of running out of spec.
Click to expand...
Click to collapse
The spare battery idea is a good one but I think one of the drawbacks to that idea is how to recharge the spares once they are dead. Energizer, Duracell and a host of other battery makers sell rechargeable power packs for not a lot of money.
I would hate to see you build one and have it short and catch fire or damage your phone not to mention the acid leaks from discharged batteries.
Edit. Just saw this in another thread. I bet a lot of us have rechargeable AA's lying around or since the are fairly inexpensive it may be worth picking some up.
http://www.batteryspace.com/battery...ndbeltcliponoffpowerswitch-rohscompliant.aspx
tincbtrar said:
I never understood portable chargers...with no disrespect to the OP, why wouldnt you just buy another battery or two? They are smaller and easier to travel around with than a portable charger without the voltage risk of running out of spec.
Click to expand...
Click to collapse
No disrespect taken. Like the ol' fried chicken guy said, where would I suddenly charge my batteries once they're out of juice? I could throw a portable charger in the car, and then go buy some cheap AA's during traveling. If I'm out of country, my charger simply won't even work (I think), due to plug incompatibilities.
Mind you, I have a Verizon Gnex, so I could use all the juice I can get my hands on. Especially during vacations, I'll likely be using the GPS, camera, and various other travel aid apps (Yelp, for one) that would likely drain my batteries a lot faster than I could imagine.
Back on topic: The NiMh idea is a good suggestion, but then I'd only be limited to using rechargables. I've seen the link to that commercially made portable charger before, but my ultimate goal is to go the DIY route. Also, the description of that item has the exact problem I'm trying to tackle, so that one is no better than something I throw together from radioshack and some Altoid tins.
mengsuan said:
Use Ni-MH rechargeable battery. Their voltage is 1.2V each, resulting in 4.8V in total.
If you use 4 Ni-MH battery with 5V regulator, it won't work. Voltage regulators are only good for stepping down, otherwise there will be improper operation.
Click to expand...
Click to collapse
Some AAs are 1.2v, while most are 1.5v off the shelf now. It is possible to use a 5v regulator to make sure the voltage does not go higher than 5v to protect your device. If the voltage drops below 5v it will simply stop charging as you need at least 5v +/- 3% or so.
What would be better is if you bought a dc-dc step up converter. This way you can use a single lithium battery (3.7v) or about 3 AAs (4.5v). The step up converter will take that 3-4v and bring it up to 5v or higher (adjustable).
Here's a dc-dc step up converter (http://www.ebay.com/itm/1PCS-LM2577...682?pt=LH_DefaultDomain_0&hash=item3cca94d2ca)
These are what most portable chargers use anyway. They step up the voltage to probably 6-7v? then bring it back down to 5v with a regulator. The reason why they step up the voltage to around 6-7v is to maintain amperage.
http://m.samsung.com/us/mobile/cell-phones-accessories/ETC-CPK008GSTA
what about using one of these to charge the spare. Love mine.
Sent from my Galaxy Nexus using Tapatalk 2
I recently got this because I had a lot of spare eneloops lying around. In 90 mins I get about 20%. For whatever reason when the phone stops charging, I can plug it into my friend's One X and his phone will continue charging where as the Nexus will charge for maybe another minute and then stop, not sure whats going on there but otherwise its a very good product.
http://www.engadget.com/2009/11/12/eneloop-stick-booster-supplies-emergency-power-to-your-portable/
rptw said:
I recently got this because I had a lot of spare eneloops lying around. In 90 mins I get about 20%. For whatever reason when the phone stops charging, I can plug it into my friend's One X and his phone will continue charging where as the Nexus will charge for maybe another minute and then stop, not sure whats going on there but otherwise its a very good product.
http://www.engadget.com/2009/11/12/eneloop-stick-booster-supplies-emergency-power-to-your-portable/
Click to expand...
Click to collapse
I was about ready to jump all over that until $40 gave me a slap in the face
I really liked what I read, but I don't think I can justify $40 on it.
rice923 said:
I was about ready to jump all over that until $40 gave me a slap in the face
I really liked what I read, but I don't think I can justify $40 on it.
Click to expand...
Click to collapse
34$ and free shipping on ebay, but i actually got it as a gift straight from japan
6V batteries can't make a voltage regulator give out 5V, let alone if you use 4,8V batteries (4x1,2V).
A Voltage Regulator needs to have its input 2,5V minimum above the output voltage (5V+2,5V=7,5V).
You'd be better off (and more stable using either 6 1,5v batteries (or 7 1,2v NIMH) and a voltage regulator.
If you are "too near" of the desired output voltage as soon as the batteries discharge a little the voltage will drop (specially if you use 500mAh batteries) and the phone will no longer charge. Better off being above voltage on the batteries. 6x1.5v=9v, after a lot of discharge,6x1.25v=7,5V will still make the regulator output 5v. (Also don't be "too far" above the voltage or most will be dissipated by the regulator).
You'd be better off using a DC-DC converter which will convert power in any form to the form you wish. Example= 1,5vx500mA=0,75W=5vx100mA (well, allways with some efficiency loss, but way less of voltage regulator).
I've seen different devices, at 5V, charging at different currents. My Samsung will require a minimum of 500mA to charge. My Nexus, with a 1000mA (1A) charger will still discharge (although at a much slower rate than when not connect). Even with the device poweroff you wouldn't be able to charge it with AA batteries.
Or EVEN Better. An external LiON rechargable 7800mAH battery that, fully charged, will charge my Nexus 7 two times

Review of Anker Astro E5 15000 mAh external battery w/pics!!!

This is a review of Anker Astro E5 15000 mAh external battery: http://www.ianker.com/product/79AN15K-WA
Being familiar with footprint of their E4 battery, when Anker announced a new E5 model with higher capacity I was expecting to see bigger and heavier model with a typical 30% efficiency loss. I know I bring it up in a lot of the reviews, but labeled capacity of ANY external battery is not what your phone battery going to see. Its a total capacity of cells inside of external battery which gets converted to 5V usb interface output and then back to your cell phone battery while charging - the efficiency loss during the conversion reduces the actual capacity by approximately 30%, with some batteries close to 40% and others maybe slightly better to 25%. On top of that, a lot of no name ebay HK sellers have batteries with super exaggerated capacity where you will be lucky to get even half of what they advertise on the label. That is why I only trust a few brands, Anker being one of them.
Once I received E5 unit for review to my surprise, the footprint stayed almost unchanged and difference in weight was negligible in comparison to previous E4 gen. But you actually get 2000 mAh more in capacity to bring it up to 15000 mAh. The battery cells are changing and improving, and I'm glad to see that Anker is keeping up with a new technology. E5 external battery is not exactly feather light, but at about 11.1 oz and 5"x3"x0.9" is manageable and actually the same as Note 2 with Zerolemon battery. The exterior is solid plastic, no flex, and comes in either white or black. For this review I chose a white unit and found it to be great to cover up any fingerprints. The top has a large power button with dual functionality to also turn on built-in led light. At full charged battery capacity, the light could last up to 700 hours if you only use it for that purpose. Next to power button you have 4-led capacity/charging indicator in 25% increments. Charging input to the battery is a standard micro-usb and has 1.5A charging speed for a fast charging of this battery. Output is a dual full usb port, rated at 2A and 1A both of which can be used simultaneously to deliver 3A of combined current. Each port current output is regulated where I confirmed charging Note 2 from one gave me max 2A and from the other one only up to 1A.
This extended battery comes with usb cable and interchangeable tips for micro-usb, mini-usb, and apple 30-pin connector. Also, it comes with a convenient storage pouch for a battery, cable, and attachment. It also comes with a detailed manual and 18-month warranty card. But there is also a big surprise. I have been reading other independent test reviews of this module and it turned out to have an actual capacity close to 11,800 mAh. We are talking about 21.5% efficiency loss which is very good considering typical batteries of such capacity have it at 30% or higher. This mean you can charge your Note 2 with a standard battery almost 4 times, or easily charge Zerolemon and have some juice still left - all this at a max 2A speed. Overall, I'm very impressed with this battery and its performance!
Here are the pictures.
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Awesome! Thanks for this! What are you using to measure the charge that is going in to the Note 2? I have an external battery rated at 12,000mah, that has both 1A and 2A ports, and would like to see what it's actually putting out, as well as check some wall adaptors that I have. Thanks for the review! Anker is also one of the few brands that I trust as well!
SwiftKey'ed from my White Sprint Note 2 using XDA Premium
stanglifemike said:
Awesome! Thanks for this! What are you using to measure the charge that is going in to the Note 2? I have an external battery rated at 12,000mah, that has both 1A and 2A ports, and would like to see what it's actually putting out, as well as check some wall adaptors that I have. Thanks for the review! Anker is also one of the few brands that I trust as well!
SwiftKey'ed from my White Sprint Note 2 using XDA Premium
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it says it in the last screenshot dude, really? LOL
Galaxy Charging Current
Galaxy Charging Current *Lite* (free version): https://play.google.com/store/apps/...hbnRpcy5nYWxheHljaGFyZ2luZ2N1cnJlbnQuZnJlZSJd
I actually found it to be relatively accurate by comparing charging time versus charging percentage. Ignore "Now" value. Just look for Max/Avg as your charging currents. This app comes very handy for those without root, like myself, to measure your charging current.
vectron said:
Galaxy Charging Current *Lite* (free version): https://play.google.com/store/apps/...hbnRpcy5nYWxheHljaGFyZ2luZ2N1cnJlbnQuZnJlZSJd
I actually found it to be relatively accurate by comparing charging time versus charging percentage. Ignore "Now" value. Just look for Max/Avg as your charging currents. This app comes very handy for those without root, like myself, to measure your charging current.
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Thanks!! Just tested it out. Like you said, the Now value isn't what the charging rate actually is. Took me reading some reviews on the Play Store to figure that out. The Now value is what the device recommends, while the Average value is what rate you're actually charging at.
I'm not sure how accurate it is though. While using my HTC wall chargers that came with my both my black Evo LTE and white one, the values are Maximum 900, Now 1798, and Average 900. I'm getting the same numbers while using the Samsung wall charger that came with my Note 2. I assume that 900 is correct for the HTC chargers, as they're only 1Amp chargers so I'm getting .9Amp from them. The Samsung charger is 2Amp though, so it should be twice as high as the HTC chargers.
EDIT : Just tested my 12,000mah PowerBank. I got 500 out of the 1Amp port, and 1700 out of the 2Amp port! Very happy with those numbers!! Especially it considering that it appears to be charging at a higher rate than my OEM Samsung wall charger!!!
SwiftKey'ed from my White Sprint Note 2 using XDA Premium
:good:Solid review bro! Something that powerful could almost charge the ZL battery twice, haha.
stanglifemike said:
...
I'm not sure how accurate it is though. While using my HTC wall chargers that came with my both my black Evo LTE and white one, the values are Maximum 900, Now 1798, and Average 900. I'm getting the same numbers while using the Samsung wall charger that came with my Note 2. I assume that 900 is correct for the HTC chargers, as they're only 1Amp chargers so I'm getting .9Amp from them. The Samsung charger is 2Amp though, so it should be twice as high as the HTC chargers.
EDIT : Just tested my 12,000mah PowerBank. I got 500 out of the 1Amp port, and 1700 out of the 2Amp port! Very happy with those numbers!! Especially it considering that it appears to be charging at a higher rate than my OEM Samsung wall charger!!!
...
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Click to collapse
Mike, which 12kmAh charger are you using? I know Anker stuff is universal for Apple/Android, while some other ones will drop your charging current to max 0.5A when connected to "apple" port. Another question, which usb cable are you using? Unless if its original Sammy cable that came with OEM charger or a cable like from monoprice with 24AWG/28AWG rating (thicker power wires to handle up to 3A of current), the cable itself its a bottleneck if its designed for a lower charging current. So for example, if you are using HTC charger/cable and then used their cable to connect to Samsung wall charger - you could be current limiting your phone (thinner wires, more resistance). And even if you are using OEM Samsung wall charger and cable - I noticed that in our house some outlets can't supply enough current depending on what other stuff is connected to the same shared power branch.
vectron said:
Mike, which 12kmAh charger are you using? I know Anker stuff is universal for Apple/Android, while some other ones will drop your charging current to max 0.5A when connected to "apple" port. Another question, which usb cable are you using? Unless if its original Sammy cable that came with OEM charger or a cable like from monoprice with 24AWG/28AWG rating (thicker power wires to handle up to 3A of current), the cable itself its a bottleneck if its designed for a lower charging current. So for example, if you are using HTC charger/cable and then used their cable to connect to Samsung wall charger - you could be current limiting your phone (thinner wires, more resistance). And even if you are using OEM Samsung wall charger and cable - I noticed that in our house some outlets can't supply enough current depending on what other stuff is connected to the same shared power branch.
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I think PowerBank is the brand, and Long March is the model. There is a long thread in the Evo LTE Accessories subforum (my other phone), and that's how I heard about it. I normally wouldn't buy an off brand accessory, but with many XDA members giving great feedback, and some have had it close to a year, I decided to try it out. Very happy that I did!! I looks a lot like your Anker actually. It has 2 USB ports for charging other devices, a 1 Amp and a 2 Amp, and also has a little LED flashlight as well. It works great and this app you mentioned showed me that the 2 Amp port is charging at 1.7 Amp(while using my HTC micro USB cable, so it may charge at an even higher rate using the Samsung cable), so I'm happy with that.
For the Samsung wall charger, I'm using the Samsung wall charger and Samsung micro USB cable. I do have it plugged in to a power strip though, so I'll have to try it plugged directly in to a wall outlet with nothing else plugged in. Thanks for the info!
EDIT : Update - after trying the Samsung charger in a wall outlet instead of the power strip, I'm still getting 900(.9 Amp). Maybe my charger is just not putting out the Amperage it should anymore, and I should just buy another Samsung wall charger if I want to get the correct Amperage. I rarely use my wall charger though, as I just use my external battery charger to charge my extra Samsung battery. When I do plug in the phone, it's usually in to my PowerBank while I'm sitting outside playing on my phone and drinking/smoking (never smoke in my house!).
SwiftKey'ed from my White Sprint Note 2 using XDA Premium
stanglifemike said:
I think PowerBank is the brand, and Long March is the model. There is a long thread in the Evo LTE Accessories subforum (my other phone), and that's how I heard about it. I normally wouldn't buy an off brand accessory, but with many XDA members giving great feedback, and some have had it close to a year, I decided to try it out. Very happy that I did!! I looks a lot like your Anker actually. It has 2 USB ports for charging other devices, a 1 Amp and a 2 Amp, and also has a little LED flashlight as well. It works great and this app you mentioned showed me that the 2 Amp port is charging at 1.7 Amp(while using my HTC micro USB cable, so it may charge at an even higher rate using the Samsung cable), so I'm happy with that.
For the Samsung wall charger, I'm using the Samsung wall charger and Samsung micro USB cable. I do have it plugged in to a power strip though, so I'll have to try it plugged directly in to a wall outlet with nothing else plugged in. Thanks for the info!
EDIT : Update - after trying the Samsung charger in a wall outlet instead of the power strip, I'm still getting 900(.9 Amp). Maybe my charger is just not putting out the Amperage it should anymore, and I should just buy another Samsung wall charger if I want to get the correct Amperage. I rarely use my wall charger though, as I just use my external battery charger to charge my extra Samsung battery. When I do plug in the phone, it's usually in to my PowerBank while I'm sitting outside playing on my phone and drinking/smoking (never smoke in my house!).
SwiftKey'ed from my White Sprint Note 2 using XDA Premium
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What you refer to is Yoobao brand power bank model "Long March". Unfortunately, there is only one official reseller of Yoobao brand in US and its KeviKev (I reviewed Yoobao Thunder 13000 mAh from them before - http://kevikev.com/Samsung-Galaxy-NOTE-II-2-N7100-Cases-and-Accessories_c47.htm). Long March is 11,200 mAh model. Did you get it from Amazon or eBay? It's a Chinese knock off of Yoobao, but it doesn't matter since it works for you. They all use the same battery cells anyway, and original Yoobao stuff might be a bit more robust and have more durable plastic shell. But listen, if the one you have works - its all good and don't worry about it!!!
Strange about Samsung wall charger. Sounds like something is gone south. Btw, don't even bother buying anything labeled as "original OEM Samsung wall charger" from Amazon or eBay - it's all fake knock offs as well. For the fun I just look on Amazon reviews, and everybody complaining about Samsung OEM wall charger not even being able to supply 1A. That's a problem with Amazon, anybody can create a merchant account and list their product under original manufacturer listing. And the rest is history because you will never be able to find original Samsung part since everything else will be a fake copy But I assume you are using your original wall charger and cable which came from Samsung when you bought N2?
flynnchen said:
Yoobao brand is quite good. I had one before. Is anker battery stable now ? I just found out this post on xda
http://forum.xda-developers.com/showthread.php?t=1361749
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That explosion has nothing to do with Anker batteries. That was highly/almost 100% due to the black cheap/low amp charger. I had a random cheap black USB charger similar to that for charging low amp Emerson bluetooth headphones, which was 400 mAH output, and we charged my brother's IPAD 2 with it, and it started to smoke. Same issue happened when charging his S3 with that cheap charger. I think it was their mistake for providing such a terrible charger, which is why it seemed the white one was probably better. The lesson is: don't charge anything that has a higher capacity/requirement with something far below it's capacity - otherwise, you're just asking for a dangerous situation to occur. That's just my two cents and observation from what I have seen, read, and personally experienced
how to charge
Excellent and informative review! 2 questions (I am a novice...). How do I charge the charger...can I use either my iphone 5 plug (output 5V/1A) or ipad2 plug? And, when charging my devices, is it the 1A socket for iphone 5, and 2A socket for ipad 2? Thank you!
---------- Post added at 10:18 AM ---------- Previous post was at 10:07 AM ----------
Excellent and informative review! 2 questions (I am a novice...). How do I charge the charger...can I use either my iphone 5 plug (output 5V/1A) or ipad2 plug? And, when charging my devices, is it the 1A socket for iphone 5, and 2A socket for ipad 2? Thank you!
maestrojohn said:
Excellent and informative review! 2 questions (I am a novice...). How do I charge the charger...can I use either my iphone 5 plug (output 5V/1A) or ipad2 plug? And, when charging my devices, is it the 1A socket for iphone 5, and 2A socket for ipad 2? Thank you!
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To charge the charger you can use any wall charger with micro-usb output. Since this is Android forum and Note 2 section, I assume you have one of those. Otherwise as you aware the charging cable for iPhone 5 is not micro-usb. But to charge your device, you can do that with any phone or tablet since charging/data cables have usb on one side (that will go into a charger) and whatever connector you are using on your device on the other side of the cable. In theory you can use either outputs.
Hello! Great review, I purchased it for 50 bucks on amazon 5 minutes ago because of the review. I am a noob, sorry in advance, I made this account to ask these two questions: 1: I just wanna use it for my iPhone 5, do i plug it in on the 1A or 2A? If both is ok, which one is better for the battery in the phone? 2: I will need an adapter, which one is better? Micro Usb to Lightning or 30pin to Lightning? I dont like the size of the 30 pin to lighting, so is it ok to purchase a micro usb to lighting instead? Does this affect anything like charging time?
Thanks for answering, have a nice day
flotschi13 said:
Hello! Great review, I purchased it for 50 bucks on amazon 5 minutes ago because of the review. I am a noob, sorry in advance, I made this account to ask these two questions: 1: I just wanna use it for my iPhone 5, do i plug it in on the 1A or 2A? If both is ok, which one is better for the battery in the phone? 2: I will need an adapter, which one is better? Micro Usb to Lightning or 30pin to Lightning? I dont like the size of the 30 pin to lighting, so is it ok to purchase a micro usb to lighting instead? Does this affect anything like charging time?
Thanks for answering, have a nice day
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You can use either 1A or 2A outputs. Your phone has a fixed charging speed and will not draw more current that it's limited to. So for example if iPhone can charger at a speed of 1A per hour and you connect it to an output that can supply 2A per hour - it will only draw at 1A per hour speed. BUT, if you have Note 2 which takes advantage of 2A per hour charging and you plug it into 1A port, it will be charging at half the speed.
Regarding cable, try to minimize number of connecting adapters. For example, you get a cable with 30pin connector and you can add 30pin to Lighting adapter to it, but with every connection you add resistance which going to affect total amount of current and can slow down the charging, etc. You want to have point-to-point cable. So I would recommend using USB to Lighting connector cable. Not micro-usb, but usb because charing ports on this external power supply are full size usb. Only the port to charge this battery is micro-usb because of a common connection with other charging cables.

			
				
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I wonder if you could try something for me.
Could you find out if the Anker will supply a phone/device while it is itself being charged? Also, whether it will keep supplying the phone/device without interruption when its own charging supply is connected and disconnected?
I want to use it like a mini-UPS for my phone while charging it from my bicycle dynamo, but for this, it needs to cope with a charging supply which stops and starts, while continuing to supply any connected devices.
I think I tried it before, and it didn't work. These external battery devices are not intended to work in pass-through mode. I think there are some other ones (I'm 100% sure if that was NewTrent), but the vendor will not guarantee the device under warranty because of an additional overheating and cut of the efficiency. This will really complicate the controller of such ext battery where it has to keep balance between charging and discharging of the same battery at the same time. I'm pretty sure Anker stuff will not allow that because they have smart current monitoring functionality built-in in order not to overcharge or over-drain the device.
But it would be an interesting experiment where you connect ext battery to the outlet and to the phone. I wonder if it starts charging battery first until it's full, and then switch to charging the phone
vectron said:
I think I tried it before, and it didn't work. These external battery devices are not intended to work in pass-through mode. I think there are some other ones (I'm 100% sure if that was NewTrent), but the vendor will not guarantee the device under warranty because of an additional overheating and cut of the efficiency. This will really complicate the controller of such ext battery where it has to keep balance between charging and discharging of the same battery at the same time. I'm pretty sure Anker stuff will not allow that because they have smart current monitoring functionality built-in in order not to overcharge or over-drain the device.
But it would be an interesting experiment where you connect ext battery to the outlet and to the phone. I wonder if it starts charging battery first until it's full, and then switch to charging the phone
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Click to collapse
I did just that yesterday, and it worked fine. Now, the anker would not actually increase its charge due to simpe physics: it charges with 1.5A from the wall, and my nexus 10 used 1.2A of those, and adding some inefficiencies on that it would likely mean that it would just hold a charge level in the anker battery, not increase it. But as soon as the tablet ramps its current draw down the anker would suck up any left over juice. This becomes even worse of course if you charge a phone at the same time.
One little note: The battery in this is not the most awesome (also the capacity measurement is a simple voltage-based instead of counting coulumbs). While charging with ~1A from the 1A port, when I added my nexus 10 to the 2A port the charge indicator actually went from 50% to 25%. When removing the tablet the LEDs indicated 50% charge again. This is due to voltage sag which is itself due to internal resistance of the batteries. Meaning: The faster you charge the more heat will be wasted in the batteries. So to really prolong the battery life you should actually charge slowly, at least as far as the Anker is concerned.
Thanks for the review, I will probably be getting one now.

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