Related
Appologies for duplicating this post here and on the accessories forum but needed a quick answer!
Anyone technically minded who can answer this....
I am using a HTC Touch Pro mains charger for my X1 (as it has a longer cable) which charges the X1 fully.
I did notice the back of the X1 getting a little warm, so double checked the outputs on the original X1 charger and the TouchPro one.
X1 = 5v 700mA
TouchPro = 5v 1A
Is this likely to be a problem?
You should definately not mix power adapters like that. On the other hand they both use mini-USB plugs so if they follow the USB standard (Battery Charging Specification) you are okay. The spec allows for up to 1,8 A, but that does not mean the X1 can take it.
I would have rather bought an extension cable for the X1 charger. Then you are safe _if_ anything happens and you damage your X1. :|
If you need a longer cable, just plug in a standard USB extension cable It will work perfectly and you can extend to plenty of meters if you need to.
Regarding the use of the 1A charger, I don't think it will be that much of a problem, but I wouldn't count on it to cause no problems either. The battery getting warm is not that odd when charging, as batteries generally generate heat when they get charged. The fact that it gets warmer with the 1A, instead of the 0.7A charger, is just because you charge the battery quicker, which in turn causes more heat. You should keep it mind though that heat is a bad thing for LiIon batteries like the X1 uses. Having it being warm reduces lifetime quicker then when it's cool.
maedox said:
You should definately not mix power adapters like that. On the other hand they both use mini-USB plugs so if they follow the USB standard (Battery Charging Specification) you are okay. The spec allows for up to 1,8 A, but that does not mean the X1 can take it.
I would have rather bought an extension cable for the X1 charger. Then you are safe _if_ anything happens and you damage your X1. :|
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Thanks for your help. I assumed - like you - that USB was USB in regards to power output. But I will take your advice and get an extension and stop using the old one.
Cheers
.
What I've seen on battery charging on mobile phones is that they have an internal intelligent charging system, at least the Siemens and Wavecom systems I've been using.
LiIon batteries are normally charged using constant voltage/constant current until a certain voltage level is reached, ~4.2V for 3.6V batteries. Then the charge current is reduced with a constant voltage until the charging current reaches zero. This implies that from a 5V charger there has to be some sort of internal charging system to make it work.
If you get a charger for USB it is the internal system that handles the current rate, not the charger. The specs on the charger shows the maximum current possible, not the charger's constant charge rate.
So if the phone's internal charging system thinks it's ok with 1A it will use it, but as mentioned earlier, it will produce more heat, but with a faster charging.
Though USB charging specs is limited to 1.8A, most charging circuits is possible to set to less current, with some part charging the battery, the rest powering the phone.
on8a said:
What I've seen on battery charging on mobile phones is that they have an internal intelligent charging system, at least the Siemens and Wavecom systems I've been using.
LiIon batteries are normally charged using constant voltage/constant current until a certain voltage level is reached, ~4.2V for 3.6V batteries. Then the charge current is reduced with a constant voltage until the charging current reaches zero. This implies that from a 5V charger there has to be some sort of internal charging system to make it work.
If you get a charger for USB it is the internal system that handles the current rate, not the charger. The specs on the charger shows the maximum current possible, not the charger's constant charge rate.
So if the phone's internal charging system thinks it's ok with 1A it will use it, but as mentioned earlier, it will produce more heat, but with a faster charging.
Though USB charging specs is limited to 1.8A, most charging circuits is possible to set to less current, with some part charging the battery, the rest powering the phone.
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Thanks very much that's very informative.
I am wondering if the X1 has this internal intelligent charging system you mentioned. Would be useful to know.
Actually the mA ratings are what the charger can deliver. Not what they actually will deliver. A 700mA rated charger will supply up to 700mA if asked for by the device. This is a two way thing. The charger side will never provide more than it's maximum rating, it's a built in safety thing. The charged side should never ask for more than it can handle, providing that it is a well built piece of electronics. I trust the X1 to be well built on this. USB standards rate a maximum of 500mA for high power devices. The X1 does adapt and thus will charge slower.
Glad this is being discussed; as my X1 is a UK model, I don't have a US wall charger.
I found some on monoprice.com, see under the Power to USB section at the bottom:
http://www.monoprice.com/products/subdepartment.asp?c_id=103&cp_id=10311
They have 3 varieties:
High-Speed WALL Power to USB Female Converter (1000mah) - Black
High-Speed WALL Power to USB Female Converter (1000mah) - White
[**cant tell a discernable difference between those two, but one is larger...**]
WALL Power to USB Female CHARGER Converter - Black (500mah)
[**many people complaining about this not charging their devices; either it really does suck or they didnt get one with enough output**]
I WONT kill the phone picking up a 1000mah?
Anyone else in my situation needing a new US charger, this site has great prices on this stuff... these adapters are under 2 bucks, and USB cables are super-cheap too!
Hey..
I want to make a pretty big backup battery for my TD2 or any other device that charges using a USB port.
I have 8 recharchable AA batteries (1,5V and 1800 mAh each) and want them in pairs off 4.
So two pairs off 6V packs and a total off 3600mAh.
But how do i acctually make this? Because i want to just plug it in some power socket so it will recharge the backup battery..
And when i need it. i just plug my phone in the backup battery so it will recharge and last ALLOT longer.
generally speaking, good socket adapters and car adapters (original ones too) have an automatic switch off when the battery gets fully charged. failing to do so can dramatically reduce the life of your battery. i think a safer (and more elegant too) solution is to buy a spare battery.
Sounds like hard work to me
Would something like this be better, I know its not as powerful as what you are proposing, and it has the cut out built into it as well.
PowerMonkey Classic
or get what I have which is this
Powermonkey Explorer
Highly recommended
PS Topic probably in wrong place, Accessories better place !?!
It charges via USB, mains, solar, has extra connectors for alot of devices.
Just my input...
If it was my problem, I would make a very simple constant current charger using a disused 19V laptop supply (doesn't everyone have one?) and a series resistor. The resistor value should be calculated from the charging current. You shouldn't go for a high current because you would need to cut off the charging when complete, or the cells would get very hot and be damaged. Proper chargers do this, but it takes a relatively complex circuit to manage the charge.
A low charge current (less than a tenth of the cell capacity) is good for cell lifespan and is safe to leave connected for a while even when the charge is complete without damaging the cell. The only drawback is a long charge time. I would select a current which charges fully in about 22 hours, so you put it on charge at a certain time and remove it next day at the same time - easy to remember.
With a 19V supply and a battery pack voltage of about 5 volts, a current of 200mA would need a resistor of value 70 Ohms - the nearest actual value is 68 ohms. Power rating would need to be 3W absolute minimum, try to get a 5W part. Your 3600mA pack should be charged after 22-24 hours. If your old laptop supply is different from 19V, you need to calculate the resistor accordingly. A low voltage supply wouldn't be suitable, because the charging current would vary too much.
Two points: Be sure to get the polarity of the laptop supply correct, and always have the supply connected to the mains when the battery pack is connected to it (otherwise the battery pack will try to put a current back through the supply, which it might not like!). Or you could incorporate a series 1A diode to protect against that happening.
I'm using a very simple supply like this to charge a 5v pack over 24 hours (it's from a bluetooth speaker - the internal charging circuit blew up) and it's perfect - I expect a long lifespan for the cells.
It's worth pointing out that putting 2 banks of cells in parallel, as you intend to, is not ideal unless the cells are matched, but in practice it shouldn't matter much.
there are 5v regulators u can buy to make your circuit work at 5v what is nice about that is that i can step up and step down voltages if the voltage fluctuates(battery power levels), btw the phones do the auto shutoff when the battery is full not the charger, because charger does not have a feedback system to read battery levels. Why do u think there is 3 or some times 4 connections on a battery and not 2
the problems u might encounter are amp levels due to long term charging but 4 1800mA AA battery will do a good charge for your phone
anyway here is a 5v reg from radioshack as referrence
http://www.radioshack.com/product/index.jsp?productId=2062599
jngtt said:
there are 5v regulators u can buy to make your circuit work at 5v what is nice about that is that i can step up and step down voltages if the voltage fluctuates(battery power levels), btw the phones do the auto shutoff when the battery is full not the charger, because charger does not have a feedback system to read battery levels. Why do u think there is 3 or some times 4 connections on a battery and not 2
the problems u might encounter are amp levels due to long term charging but 4 1800mA AA battery will do a good charge for your phone
anyway here is a 5v reg from radioshack as referrence
http://www.radioshack.com/product/index.jsp?productId=2062599
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I might be misunderstanding you, but if you mean charging the cells from a 5v regulator, that would be a bad idea. NiCad or NiMH cells shouldn't and can't be charged from a constant voltage source. When you start charging the current would be too high (the 7805 would probably switch itself off) and the charge would never finish either, as 4 cells in series have an endpoint voltage of about 5.6 - 6.0V.
But perhaps you didn't mean that... (in which case apologies for butting in)
Pete_S said:
I might be misunderstanding you, but if you mean charging the cells from a 5v regulator, that would be a bad idea. NiCad or NiMH cells shouldn't and can't be charged from a constant voltage source. When you start charging the current would be too high (the 7805 would probably switch itself off) and the charge would never finish either, as 4 cells in series have an endpoint voltage of about 5.6 - 6.0V.
But perhaps you didn't mean that... (in which case apologies for butting in)
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The 5v regulator just sets the voltage to be 5 volts as with all usb ports and usb chargers, the HTC charger that comes with the phones pushes 2A, the usb ports on our PCs pushes 0.5A. Ampere is just current, if u think that is too much amps u can put a fuse. This is the first time someone told me constant is bad
btw do u know how cells and battery work?
Going back to the original post, Overloaded just wanted a way to recharge his proposed battery pack from the mains, if I read it correctly.
I don't see where a 7805 5V regulator fits into this, either for charging the phone (the battery pack is 5-6V and the 7805 needs at least 7V to function) or for charging the battery pack (for reasons I've already outlined).
u are right, he does not need the 5v reg, infact all he needs to do is put the battery in serise with a diode to prevent feedback and he should be fine
Slightly off topic,
I recently got hold of two 11v LiPo packs, a regulator, a fast charger and all the cable and connectors to buils a 4400 mAh power souce. At 5v this gives circa. 8800 mAh. I bought it in a model shop sale and I've wanted to play around with the setup for some time.
The two packs are to big, but one on it's own is not too bad. And they were cheap!
Hello,
i ve been searching for a way to extend the autonomy on the a501.
do you think i can use a cheap 12V lithium battery to charge it or take over when the internal battery is depleted ?
i m not very knowledgeable in electronics, i wouldnt want to damage the internal battery.
there seem to be very few commercial products that would fit this tablet and i m not really interested. i dont have 50$ for a +2h battery life --;
i was thinking of buying a 12V 5000mAh something battery from china and solder the appropriate DC connector on it, but im wondering if there are issues like, the Current needs to be stable at 1,5A or i might reduce the internal battery durability, things like that.
can anyone answer that ?
It's more complicated than that. The power supply probably has a circuit to regulate the flow of energy to the tablet, perhaps the tablet itself also has a circuit that works together, I don't know.
Short answer: buy a second power adapter
There are backup battery/chargers. Scosche goBAT for example.
Just Google around to find the best fit for you.
GullyFoyle said:
There are backup battery/chargers. Scosche goBAT for example.
Just Google around to find the best fit for you.
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How would that work? Does the goBAT include a charging tip compatible with the A500?
Hello,
thanks for dropping by
its not helping really this is bs
power cat you say "probably" regulates the current. yes that is what i wrote that is what i hoped someone would clear up for me. i dont see how buying another wall charger is going to help me extend the tablet autonomy i would just as well carry the original one around.
gullyfoyle same sideways reading of the OP i would not pay 80$ for a marketed battery/charger.
i hope there are still people out there who can give an educated answer :/
this guy for example http://www.youtube.com/watch?v=LqxhEkDGkbg he says he learned it the hard way (bricked his phone?) because he put 4x(1.5V?) batteries to charge his iphone without the resistors (to get the voltage from 6V down to 5V?)
so there again, can there be issues with the discharge current rate or is it something about lithium batteries behaving differently from alkaline ones ?
i think i ll go ahead and try anyway. worst case scenario the battery will just sit there not putting out anything.
Why wouldn't you pay $80 for a backup battery charger. It was just an example. I'm sure you can find one cheaper after Black Friday, or even with a bit of Googlefu.
We aren't talking about normal chargers but portable charge devices.
http://www.scosche.com/consumer-tech/product/2073
For anyone in need of extra power, the goBAT II provides an innovative solution to the dreaded ‘low battery’ warning. The goBAT II is a powerful backup battery and dual port charger for your mobile devices. The internal 5000mAh ion battery will keep your devices going long after they normally would.
Advantages and Applications
A drained iPhone 4 can be charged 2.6 times with a fully charged goBAT II. An iPad can be charged up to 55% of full charge. This is the ideal battery for long commutes, airport travel and camping.
The goBAT II provides 2 USB charging ports that can be used at the same time. A 2.1 Amp port gives you the ability to charge mobile devices including tablets (iPad and Samsung Galaxy Tab). An additional 1.0 Amp port lets you charge your additional devices (iPhone, iPod, etc.).
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Remember this is JUST AN EXAMPLE. The idea is to show these devices exist and are available for purchase.
http://www.engadget.com/2011/02/23/scosches-gobat-ii-portable-battery-pack-handles-two-usb-devices/
We'll just keep it real simple for you: the object you're looking at above is the Revive II charger, but slimmer, and with a rechargeable battery pack thrown in rather than a wall / cigarette adapter. Got it? Good. The goBAT II contains a 5000mAh rechargeable lithium ion battery, and it offers a pair of USB ports for charging. One's a 10-watt (2.1 Amp) port capable of handling high-maintenance devices like Apple's iPad, while the other is a more conventional 5-watt (1 Amp) socket. Scosche is also throwing in a USB adapter for the Galaxy Tab, theoretically letting those with divided households charge both an iOS and Android tablet at the same time. Brain melting, we know. It also works with the company's Revive charging app, which indicates how long a device will take to charge on any of Scosche's chargers and can also be configured to send an email notification once a device has been fully charged. She's all yours down at the source link for $89.99
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See, others deem it "BRAIN MELTING".
And the cost of that type of thrill is reasonable, for the job it does.
But I can understand how someone would encourage another person to experiment with the guts of electronics they don't fully understand. Screw it up and you can always buy a new one.
Then again, you could buy three or four Gobats and save all the fuss and bother.
mr.bryce said:
Hello,
thanks for dropping by
its not helping really this is bs
power cat you say "probably" regulates the current. yes that is what i wrote that is what i hoped someone would clear up for me. i dont see how buying another wall charger is going to help me extend the tablet autonomy i would just as well carry the original one around.
gullyfoyle same sideways reading of the OP i would not pay 80$ for a marketed battery/charger.
i hope there are still people out there who can give an educated answer :/
this guy for example http://www.youtube.com/watch?v=LqxhEkDGkbg he says he learned it the hard way (bricked his phone?) because he put 4x(1.5V?) batteries to charge his iphone without the resistors (to get the voltage from 6V down to 5V?)
so there again, can there be issues with the discharge current rate or is it something about lithium batteries behaving differently from alkaline ones ?
i think i ll go ahead and try anyway. worst case scenario the battery will just sit there not putting out anything.
Click to expand...
Click to collapse
You will break your tablet.
The charger contains a complex integrated circuit. Sticking on a few resistors isn't gonna do ****.
Look at this for example, a simple wind generator has a complex charging circuit to regulare all the power:
http://www.instructables.com/id/How...nd-turbine/step8/Build-the-charge-controller/
Just google "how to make a charge controller" it's really not as simple as you think.
Quote from the site:
The general principal behind the controller is that it monitors the voltage of the battery(s) in your system and either sends power from the turbine into the batteries to recharge them, or dumps the power from the turbine into a secondary load if the batteries are fully charged (to prevent over-charging and destroying the batteries).
ok thanks ^^
now i understand that part
Short answer: buy a second power adapter
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you are saying the overcharge controller (and other safety features) are all in the wall charger and are not integrated in the tablet.
so if i really really wanted to try i could plug any battery between 12 and 24V to this little guy couldnt i ?
http://www.ebay.ca/itm/220826123824#ht_3149wt_1163
As far as I know...as long as the voltage is correct (eg 12 volts) and the power adapter can produce the required amperage (1.5A) then the tablet will only take the current it can use.
So even if the power adapter is capable of producing 10A say, it doesn't mean it's forcing the 10A onto whatever is connected to it. If you use 1.5A (and if there was a way to connect multiple devices to it) you would still have 8.5A of current you could still take.
Oh the charge regulator would not be in the power adapter, that would be a very stupid design. It would be in the tablet it self to regulate how much charge it requires. I don't know of any power adapter that takes feedback from what it's charging to regulate the current.
It's the same with laptops, that's why you can buy universal laptop chargers when the one you have breaks, you just need to make sure it can supply enough amperage to power your device.
The power adapter is just a simple device that converts 110-240v 50/60hz voltage to 12v and upto whatever amperage it is designed for.
Power plugs in the house are designed at 110-240v to a maximum of 2400W (so ~20a for 110v and 10a for 240v) do you think whatever you plug into it uses up 2400W of electricity at once? No, it just takes what it is required (amperage), that's why you can plug a power strip with like 2-10 additional plugs without any problems unless if try to take more than 2400W in total.
Basic high school physics should of taught people this.
first sensible answer i get thank you daemos i m just not gonna take any chances considering the lithium technology and the fact they could use a "stupid design" for shorter gadget lifespan. if anyone has ever modded a car charger i d love to read about it.
mr.bryce said:
first sensible answer i get thank you daemos i m just not gonna take any chances considering the lithium technology and the fact they could use a "stupid design" for shorter gadget lifespan. if anyone has ever modded a car charger i d love to read about it.
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Lithium ion batteries must be charged at a very specific voltage. So all charging regulation mechanisms would need to be inside the tablet.
I'm pretty sure the ones inside the tablet are definately below 12V so anyone thinking that the AC adapter has any fancy mechanisms to detect feedback, and regulate charge and control the voltage given to the Li-ion cells is incorrect.
Is it safe to use one of THESE to charge or run the tablet?
They also have a 6800mAh ver.
WOW YOU MEN Complicate everything
SIMPLE EASY .. Look at the output voltage of the the power brick for the iconia.. the part that you plug into the wall..
got something that OUTPUTS 12V AT 1.5 AMPS and you are done.. the Li Batteries as in all LI BATTERIES HAVE THERE OWN charging regulators in them.
The reason for this is because if a Battery is drained to a low state it will GET HOT AND OVERHEAT.. NI-CD Batteries can take and handle this heat.. Li batteries become a mini bomb at these temps.. So the are self regulating.. This can be proven by getting a cordless drill hold the shaft from running.. the drill will heat up the battery the device will STOP FUNCTIONING.. Remove the battery and put it back in . it will work again..
Now with that said.. most Li devices say make sure you have 20% or more battery life before flashing and so on.. This is because the DEVICE WILL NOT RUN On the power port. the port only connects to the battery. and in some cases the display lighting.. My cell is this way. if i run the battery until its dead or using gps on it. it will drain the battery faster then it can charge . causing it to not work until you charge it for 5 minutes or so.. this would assume that using a external battery to charge it .. the external batteries themselves would need to be more then 12 volts and atleast double the amps.. then regulated to the 12v 1.5 amps . think of this like pooring water thru a funnel.. to maintain the 12v 1.5 amps. You can test my theory by taking the battery out of your cell phone and trying to run it just on the power adaptor only.. I KNOW MINE WILL NOT RUN.. however if it has older battery technology it will..
Quick question: can I use the N10 charger to charge my Galaxy nexus? This is the normal USB charger and not the POGO charger. The only reason that I ask is that the end that connects to the wall is significantly bigger on the nexus 10 charger than the galaxy nexus charger. Figured i would ask before I burn anything.
No problem at all.
Just look at the chargers you have.
Voltage will most likely always be 5V. Lower amps can hurt the charger but not the device.
One easy way to look at it is this:
Voltage is provided by (or pushed) by the power supply.
Amperage is taken by (or pulled) by the device being powered.
In other words, while the voltage is a constant and should match, the amperage is something that varies based on the devices need. Your computer will "pull" more amps when it's working hard than when it's not. The voltage will remain the same regardless.
The amperage rating of a power supply is the maximum number of amps that it's able to provide if needed.
Thus, as long as you replace your power supply with one that is capable of providing as much or more amps than the previous supply, you'll be fine.
Of course you can!
I use N10 charger to charge my Nexus S and I haven't problem.
Great! thanks everybody!
I don't know much about voltage and stuff, but with the 5.3v charger, I assume it's okay to use a 5v to charge the Note 3, it just might be a bit slower, correct?
Now what about using the 5.3v charger on the iPad Air? I can't find any info on its charger, or online, of what voltage it uses. will the 5.3v be too much for it or anything?
guttertrash said:
I don't know much about voltage and stuff, but with the 5.3v charger, I assume it's okay to use a 5v to charge the Note 3, it just might be a bit slower, correct?
Now what about using the 5.3v charger on the iPad Air? I can't find any info on its charger, or online, of what voltage it uses. will the 5.3v be too much for it or anything?
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It's perfectly fine to use 5v, that's standard. The voltage the wall adapter puts out is not what will determine your charge speed, its the amperage your device draws - which I believe is capped at 1800 mah for the note 3. It doesn't matter what the amperage is (it can be higher), but the note 3 will only draw 1800 mah max and lower if the source is lower. When it comes to the 5.3v charger, there's a bit of mixed information from what I've gathered. Plenty of people have used it with no problems considering .3v is a fairly small difference, but there will be some that tell you otherwise. I personally avoid 5.3v just because I have plenty of alternative chargers.
If the source is lower, it will increase the time it takes to charge. But 5.3 volts as an output will actually drop to 5 once it is loaded by your device. Just like 5 drops to about 4.7 when loaded by a device. The unloaded output of a charger is always higher than when it is connected.
It's the device that determines the amount of charge drawn, the numbers on the charger are just the max-charge it can provide. (Think of it like a car. Your engine can go up to 200Kph, but the actual speed is determined by how much you tell it to give you.)
I charge my Note 3 with my 15V Asus TF700 charger. It still only charges at the max the Note 3 can draw.
Essentially a 15V charger can safely provide the 5V, but a 5V charger can never provide the charge for a device which requires 15V.
Besides, a USB2.0 cable can't go over 5Volt anyway, so your iPad is safe.
ShadowLea said:
It's the device that determines the amount of charge drawn, the numbers on the charger are just the max-charge it can provide. (Think of it like a car. Your engine can go up to 200Kph, but the actual speed is determined by how much you tell it to give you.)
I charge my Note 3 with my 15V Asus TF700 charger. It still only charges at the max the Note 3 can draw.
Essentially a 15V charger can safely provide the 5V, but a 5V charger can never provide the charge for a device which requires 15V.
Besides, a USB2.0 cable can't go over 5Volt anyway, so your iPad is safe.
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Now I'm not trying to be rude or anything, but I think you have a few facts astray here. If you can prove me wrong I'll be happy to learn since it has been awhile since I took circuits. First off your right about the device being a big factor in the rate of charge, in fact technically the charger is in the device, the wall adapter is just the source. The source will force a certain voltage, i.e. 5v or 15v, and can provide up to a certain current (amperes). The charger in the device then determines how much of this current to draw.
With all that being said, the reason you can use your asus transformer charger is because it only forces 5v unless the transformer is plugged in at which point it kicks it up to 15v. So your not actually plugging a 15v source into your n3, if it were possible you'd be on thin ice. Also, I'm pretty sure you'd be able to charge your asus via say the note 3 charger (really slow though), probably not while its turned on, but turn it off leave it plugged in for a few hours and you should see a change.
A USB cable is just a wire, if you put 5.3V on it then your device receives 5.3V (minus voldage drop due to the resistance of the cable but that's negligible unless you're using a cheap thin cable). That said, 5.3V should be within tolerance for pretty much every USB charging device out there including the iPad (which I think uses a 5.3V charger itself).
Sent from my SM-N900T using xda app-developers app
Cool, good to know I wont fry either device. Thanks for all the help
Solarenemy68 said:
If the source is lower, it will increase the time it takes to charge. But 5.3 volts as an output will actually drop to 5 once it is loaded by your device. Just like 5 drops to about 4.7 when loaded by a device. The unloaded output of a charger is always higher than when it is connected.
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Galaxy Note 3 have digital charger. so, I don't think undervolting is the case
Sent from Note 3
MILJANN said:
Galaxy Note 3 have digital charger. so, I don't think undervolting is the case
Sent from Note 3
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It's not undervoltage. The resistance "R" of the USB cable is fixed (varies from cable to cable, but is constant for any single cable), so as the current load "I" increases the voltage "V" lost across the cable also increases, according to V = I*R.
Given a 5v source, loaded to 1800 mA, you would expect to see 4.7v at the phone's end of the USB cable. The resistance of the USB cable itself comes out to around 0.1666666 Ohms in that scenario, which is a perfectly reasonable value for the gauge wire used in those cords.
CalcProgrammer1 said:
A USB cable is just a wire, if you put 5.3V on it then your device receives 5.3V (minus voldage drop due to the resistance of the cable but that's negligible unless you're using a cheap thin cable).
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Or using a long cable. With my (S5) 5.3V charger, i can finally use those 3M/10ft cables, which is really convenient for me
pizzaman79 said:
Or using a long cable. With my (S5) 5.3V charger, i can finally use those 3M/10ft cables, which is really convenient for me
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In lieu of using higher voltage chargers to use with long cables, you can also use chargers that provide more current @ 5V or, of course, lower resistance cables.
I'm afraid not. The voltage will drop too far below 5.0V, the device will not accept the offered power, no matter how high the charging current. That's both based on physics and personal experience. Resistance in cables is an issue at 10 metres, even those with high gauge copper cores.
Edit: Delete.
pizzaman79 said:
I'm afraid not. The voltage will drop too far below 5.0V, the device will not accept the offered power, no matter how high the charging current. That's both based on physics and personal experience. Resistance in cables is an issue at 10 metres, even those with high gauge copper cores.
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You are absolutely correct, however that isn't exactly what I was trying to share. I was trying to share a solution to situations where the charger cannot keep up and thus the voltage sags. I did not expect a 10metre situation. The longest I have is 5m. On my 5 metre cable, I don't notice any appreciable voltage drop from any of my chargers, so I generally consider it negligible. How much do you drop across 10 metres and at how many amps?
On a side note, I think the phone has some kind of safety when it comes to voltages. I just plugged in my 5.3V charger from my s5 into the s3 and it seemed to work fine. However, I also recently, and I only just realised this, plugged in a 7.2V supply to my S3 and though it did not charge, nothing bad seemed to happen. It was an off brand 5V USB Charger and when it died, it cranked up the voltage.
fusionstream said:
You are absolutely correct, however that isn't exactly what I was trying to share. I was trying to share a solution to situations where the charger cannot keep up and thus the voltage sags. I did not expect a 10metre situation. The longest I have is 5m. On my 5 metre cable, I don't notice any appreciable voltage drop from any of my chargers, so I generally consider it negligible. How much do you drop across 10 metres and at how many amps?
On a side note, I think the phone has some kind of safety when it comes to voltages. I just plugged in my 5.3V charger from my s5 into the s3 and it seemed to work fine. However, I also recently, and I only just realised this, plugged in a 7.2V supply to my S3 and though it did not charge, nothing bad seemed to happen. It was an off brand 5V USB Charger and when it died, it cranked up the voltage.
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The voltage drop is dependant on gauge, copper quality and length. I never measured it at both ends but i estimate 0.3-0.5 volt based on what chargers do and don't charge what phones at 10ft. Note that i mixed up ft and metres lol, my cables are 3m. At that length voltage drop is an issue for me.
7v would perhaps be fine for a 10m cable I wish we knew the tolerance range of what voltages (at the usb in) common smartphones accept.
I think the reason the galaxy tab S tablets have a 5.3volt charger is to compensate a bigger voltage drop through the longer charging cable provided.
The voltage must be the correct voltage or near to it. I think from what others have said 5.3 is near enough to 5.0Volts.
F 0.95