Charging cable MUST be Samsung-branded, or doesn't matter?

[ylexot]

- Voltage increases when current decreases with these chargers

No it doesn't. Voltage is a regulated 5V (unless you got some serious POS chargers). Amperage is up to the maximum. If a device can't handle as much as the charger can put out, the amperage provided is what the device can handle. If the charger can't put out as much amperage as the device can handle, the device either doesn't charge or charges more slowly (depending on the device circuitry).

 

[jerofld]

- Voltage increases when current decreases with these chargers
- This has nothing to do with mAh, which is battery capacity; this strictly deals with the charging circuitry as it pertains to being connected to an out-of-tolerance power supply
- We don't know definitively what the SIII's tolerances are since "Technical" Support would rather give up and give an irrelevant answer and call it a day; we can only infer the SIII requires 1A by its included travel charger
- I am a retired EE--which means little beyond relying on general electronic principals if we don't know how the SIII (and the connected charger) was actually built

E=IR, yes? You're assuming that R is staying constant. A simple regulator with a feedback circuit would maintain 5 VDC while allowing current to change as necessary. The feedback circuit would tell the regulator that the current being drawn is less than what it was expecting, causing the Op Amp to decrease it's output, but maintain 5 VDC. The components are cheap and fit on a penny.

If the device being powered is trying to draw more current than the charger permits, a simple current limiting circuit to keep the current from exceeding maximum of the power source and that would prevent overheating or electrical damage.

I suspect both the charger and the phone have these two circuits built in.

No it doesn't. Voltage is a regulated 5V (unless you got some serious POS chargers). Amperage is up to the maximum. If a device can't handle as much as the charger can put out, the amperage provided is what the device can handle. If the charger can't put out as much amperage as the device can handle, the device either doesn't charge or charges more slowly (depending on the device circuitry).

I agree. The only real impact of using a lower rated charger would be that the phone charges slower. I would suspect that the charging circuitry is the same between the AC charger and the USB path (that is restricted to 500 mA) and the OPAMP just is built to handle anything from 300 mA to 1 A of current. But without part numbers, there's no way to verify that.

 

[Szadzik]

Been charging a few phones for 3 years now with a charger that only outputs 500 mA and all phones' chargers were at least 700 mA and so far, in three years nothing has happened.

The theory that if you connect to a charger that is of lower amperage than the original charger, the phone might blow up definitely stinks.

Would Samsung design a phone that would be likely to blow up when connected to your normal USB port? I think not. All chargers in the past were 500 mA and they worked just fine.

 

[JD_Racer_Dad]

The USB charging issue is not a V=IR issue until you get past the USB data pins and the two USB charge only protocols.

The USB port from your PC limits the output to .5 Amps by recognizing the 2 data lines. The protocol is there to protect the PC.

If you have one of the newer charge ports that allows more than .5 Amps you will need one of two things. They should be color coded different than the data USB ports.
If it uses the non-iPhone protocol "nothing". It will charge at the 1 Amp or rated output.
If not you will need a charge only cable, generally two wire USB without the data wires.

The USB Charger Only chargers (car or home) either short the data pins in the charger for non-iPhone chargers or they are iPhone chargers and read the data lines to regulate charge output.
A "Universal" USB charger that claims to work on an iPhone is not "Universal".

I have a dual USB charger with 1 Amp on one side for non-iPhones and 2 Amps on the other side for iPhones and iPods etc.

Last week I drove 45 minutes with the Navigator on and the screen lit, phone on and talking, a radio app running and the battery app and other misc background stuff on.
I used one outbound and the other on the return trip.

The Battery registered charging and AC for both in settings.
While charging and running it continued to loose charge with the 2 Amp iPhone protocol side.
While on the return trip and on the 1 Amp non-iPhone side it charged and functioned fine.

I have a handful of iPhone and non-iPhone chargers, all the same deal home or car.

I did a 7 1/2 hour rode trip yesterday with everything on including the screen the whole way with a different non-iPhone USB car charger, charged the phone and kept it charged. This with screen on and GPS.

Now after you know what your charger is doing with the data pins you can check the Amp output and some of Samsung's older chargers are only .5 Amps.

 

[Rolo42]

- These comments only account for the power supply, not the phone's circuitry, which may not be getting enough power
-- An analogy: you can supply an incandescent light bulb with less power than its rated (dimmer switch) and it will still work, just not as bright; however, you cannot under power fluorescent lights and get the same effect, for you'll get flickering lights, if at all, and risk burning out the ballast. The question is whether our phones work like incandesents or fluorescents; I don't know

- Max current rating on a power supply does not mean that current is constantly being supplied unconditionally; current is pulled, not pushed--i.e. if the phone is only pulling 700mA, then a 1A power supply will deliver 700mA. Contrarily, if the phone tries to pull 1A and the power supply can only provide 700mA, any number of things can happen depending on how the phone and power supply were designed, which we don't know and without knowing, I (or anyone else) cannot say that there aren't any adverse consequences to using other power supplies. Until we can get some facts from Samsung (unlikely), we're all guessing.

My opinion is based on general electronics principals and prudence. Other opinions are based on observations (it charged without catching fire therefore it must be fine). I am not saying anyone is wrong in that but I am saying using <1A power supplies could incur risk.

Personally, I don't wish to risk less-than-optimum performance of my phone (whether catching fire or simply shortened battery longevity) to save a few dollars.

 

[LauraN]

I just thought I would mention even though this is such an old post but even now, my phone is only 7 months old and all my charger port is burnt, and is slowly getting worse! So they havent fixed the problem obviously or there are some faulty batches! So I thought I would warn people just incase ya know

 

[Zoandroid]

Hi LauraN,

Welcome the forum!

I suggest you take some kind of action, especially if the issue is getting worse. Might be a good idea to have someone look at it. I'd hate to see it end up in a fire for you.

 

[LauraN]

Yea I am, it is being sent back to samsung tomorrow to be replaced

 

[Zoandroid]

Good idea.

 

[chesa319]

I tried several universal chargers to chargs my galaxy s3 with no luck. When I tried chargers that came with my kids phone or husbands phone it would charge. So I went to radio shack to get a charger that would work on my phone so I wouldn't have to borrow my families chargers, I was told that this is a common problem with the galaxy's.

 

[javamann]

I have multiple charger from 3 different phones that I use. Never checked their voltage, wattage , or whatever else counts in these chargers and never have had any kind of prblem with my S3. Do not know what all the fuss is about.
JM

 

[guy48065]

I saw an off-hand comment somewhere else in this forum about activating the phone's "high-speed recharge". IF there is such a thing then a better charger might make sense.

Can ANYBODY address whether there's more to it than "doesn't matter"?

I'm unclear:
Does the phone circuitry control the charge rate?
Do better phones have better charging circuits--or do all just have a current-limiting resistor as the "charging circuit"?
I've been seeing high-current adapters putting out more than 2A--will the phone handle 2A or is the extra output wasted (BS marketing)?
What if there was a regulated 5A charger--or I build one?
Does the phone cut off charging at 100% or continue to trickle charge?
Or does the charger sense when the battery is full?
What current can a USB cable handle? Never any ratings on them...



I'm not an EE but I once stayed at a Holiday Inn Express that was hosting an EE convention
;-)

 

[Zoandroid]

I'll try and help based upon what I have learned over the years in hobby electronics. But I am far from any kind of expert. My answers will be following each question, within your quoted text.

I saw an off-hand comment somewhere else in this forum about activating the phone's "high-speed recharge". IF there is such a thing then a better charger might make sense.

Can ANYBODY address whether there's more to it than "doesn't matter"?

I'm unclear:
Does the phone circuitry control the charge rate?

In short, yes.

Do better phones have better charging circuits--or do all just have a current-limiting resistor as the "charging circuit"?

Probably true, but no way to know for sure without knowing the circuitry inside each device.

I've been seeing high-current adapters putting out more than 2A--will the phone handle 2A or is the extra output wasted (BS marketing)?

Ohm's Law for DC circuits says that when voltage is applied across a given resistance, a given current will flow. Aside from using conducting wire that is too small for that current, and would add more resistance, and likely heat up and melt as a result, the amount of current that will flow is a constant tied to the internal resistance. The reason they make larger capacity charger wall warts is because some devices will pull more current than others. But if you have a device that draws 1 amp charging, it will do that even if you connect it to a 10 amp charger. So using a charger of higher amperage capacity than what the charging device is rated to use does nothing at all. And is usually safe. However, using a smaller capacity charger, such as half an amp (500 mA) will also work, BUT it will take longer to charge. Likely twice as long.

What if there was a regulated 5A charger--or I build one?

See above.

Does the phone cut off charging at 100% or continue to trickle charge?

If the device circuitry has a smart charger, it will taper off and stop charging at or near 100%, and hold that if left plugged in. If the charge starts to fall, it will resume charging, then stop again when fully charged. The S3 has such circuitry. I plug mine in all night every night, so it has a fully charged battery in the morning.

Or does the charger sense when the battery is full?

See above.

What current can a USB cable handle? Never any ratings on them...

It would be dependant upon how each one is constructed. Some have very fine wire, so can handle less current. Some have rather thick wire, which can handle more current. To really know that answer one would need to know the gauge of wire inside. There are charts where you could then match wire gauge to current. I do not know the current rating of the actual connectors typically used in a USB cable, but it probably is rated higher than the wire is rated in most cases.

Hope this helps.



I'm not an EE but I once stayed at a Holiday Inn Express that was hosting an EE convention
;-)

 

[Zoandroid]

I can attest to being able to charge different micro-USB and mini-USB devices with different cables. Branding does indeed seem irrelevant. BUT.... I have seen several cables that simply would not work. I think they were just poorly made. I've been charging my S3 for months now with cables I bought that have right angle plugs on each end, making it more comfortable to use the S3 while it is charging. The cables are rather heavy compared to most I have seen, but no knowning how much of that thickness is in the outer insulation.​

One problem that also affects charging, and can seem like a bad cable, is that the charging connectors on devices can sometimes loosen their grip on the plugs, or even come loose from the mainboard inside the device. They don't take abuse very well. The Kindle Fire is well known for losing connection internally. I had to replace one of the board mounted jacks once. Not a fun job, as they use extremely tiny SMD leads, and the main lugs soldered to the board are too short. They do not extend even flush with the other side. So a very poor design, and very tricky to solder. If your cable seems loose when plugged in, it likely isn't a cable problem, rather the connector on the device.

 

[guy48065]

Another question that would be useful to get an answer for is what is the maximum charging rate of an S3 battery? For some batteries you can find this spec in the mfr. literature--but probably not for these cheapy chinese-made packs. So we just trust the phone "knows what to do"? What about charging stands & docks? Browsing accessories online I ran across a dock that claimed to have a "smart charger" built in. That would be pointless if the phone has it's own elaborate circuit--and probably wouldn't work if the phone had a current-limiting resistor. I imagine a smart charger needs to be connected directly to the battery in order to get the feedback voltage needed to tell when the pack has peaked.

Claims like that just muddy the water for me & that's why I hope for a definitive answer. I gotta believe someone here knows.

 

[gordonfink]

I have found that some S3's won't accept an aftermarket charger, while most will. Some will only accept a factory charger.

 

[Zoandroid]

So we just trust the phone "knows what to do"?

Yes.

Until we would start hearing about S3 phones bursting into flame due to charger issues, we have to assume the engineers who designed the phone, and selected the battery, made the right choices.

One interesting side note I discovered when looking up S3 batteries on Amazon just now ( I wanted to know what kind of battery it is before I posted this reply) is their reference to NFC. Apparently the NFC technology must work together with the battery. Perhaps they include something needed for that to work.

Battery charging technology can be rather complex. Perhaps you might like to take a look at this site:

Charging Lithium-Ion Batteries – Battery University

 

[guy48065]

Until we would start hearing about S3 phones bursting into flame due to charger issues, we have to assume the engineers who designed the phone, and selected the battery, made the right choices.

Haven't you heard? They do on occasion.

Battery charging technology can be rather complex. Perhaps you might like to take a look at this site:

Charging Lithium-Ion Batteries – Battery University

Battery performance and charging borders on being a religion to many.
That's why I'm surprised so little is known about our batteries & charging methods. It's not like everyone is happy with how long phone batteries last each day, or how short their lifespan is.

 

[Zoandroid]

Haven't you heard? They do on occasion.


Battery performance and charging borders on being a religion to many.
That's why I'm surprised so little is known about our batteries & charging methods. It's not like everyone is happy with how long phone batteries last each day, or how short their lifespan is.

Wow! I had not heard of this, so I Googled it. Seems it has happened several times. I had no idea. I wonder how old the phones were that did catch fire? I'm hoping if that were going to happen, mine is beyond the stage where it would. Must have been some kind of internal short or circuitry malfunction.

Battery technology has a long way to go, IMO. Personally, ever since I was a kid in the 60s, I have wanted what Tesla tried to do. The wireless transmission of electric power, to free us from cords and batteries. Maybe one day if electronics get small enough and they use so little power we will come to that. RF tags and induction charging are the first step.

 

[AndyP2002]

Cables are cables. You'll be fine with generic cables.

Much as I'd love to agree with you, that's not right.

Although there is supposed to be a USB powering specification, different manufacturers have implemented it in slightly different ways.

I have in front of me right now a brand-new generic USB "wall wart" power supply. My Sony Xperia smartphone recognises it and charges from it fine, but my wife's Samsung Galaxy Ace does not even register that it is connected, and does not charge from it at all.

 

[Zoandroid]

Much as I'd love to agree with you, that's not right.

Although there is supposed to be a USB powering specification, different manufacturers have implemented it in slightly different ways.

I have in front of me right now a brand-new generic USB "wall wart" power supply. My Sony Xperia smartphone recognises it and charges from it fine, but my wife's Samsung Galaxy Ace does not even register that it is connected, and does not charge from it at all.

There are also micro USB cables that use the typical 4 conductor ends, but in fact have only 2 conductor wiring. They can charge, but not transfer data. Some have much heavier leads these days, especially for the newer devices that ship with a 2A wall charger.

Also, if the typical "wall wart" does not say "regulated" on it, then it is using the specific load of the device for which it was built to pull the right amount of current to keep its voltage at the correct level. Draw more or less current through it (using it to power something else) and the output voltage can vary a great deal.

So although using a cable or charger for other items than is was made will often work, there can be problems sometimes.

 

[gotip]

I'd been using the Samsung charging cable for about a year and recently noticed the charging time was taking forever to charge the battery. Like all night and even then it would be at 98 percent. I tried another charger and cable from another product I had and it is back to going from minimal charge to full charge in a couple hours. I was worried it was the connector on the phone, but it appears the connector on the wire had been causing the problem. Happily now just using the new wire and all is good.

 

[Sharisma1]

As long as it's micro USB then it will work. If the charger outputs a lower current than the Samsung charger then it might take longer but that's it.

I have a Samsung Note 2 I believe - I used my blackberry charger - my current Samsung charger is loose & after I used the blackberry charger no longer charges it - is that just coincidence or has it caused an issue?

 

[Zoandroid]

I have a Samsung Note 2 I believe - I used my blackberry charger - my current Samsung charger is loose & after I sued the blackberry charger no longer charges it - is that just considence or has it caused an issue?

It is possible the jack on the Note has deformed and loosened, causing a bad connection. You might want to have the people who sold the tablet take a look at it.

 

[Sharisma1]

It is possible the jack on the Note has deformed and loosened, causing a bad connection. You might want to have the people who sold the tablet take a look at it.

It was loose before I used my blackberry charger. Will have to do that & see what they say.