Charging a Nokia Lumia 920/ any phone with li-on battery

[Adriaan NL]

Today, I bought a Belkin wall charger, which has 2.1 AMP/ 5V (without a cord). It's compatible with tablets and phones, the package specifically mentions iPad, iPhone, Android, and Blackberry (no WP, as expected). The salesman said it is compatible with ALL phones with a USB charging possibility, like the 920.

The OEM/ official Nokia charger is also 5V, but only 1A(MP).

Is it possible, without damaging the 920, to charge with the Belkin charger as well, even though it has more AMP? I am using my Moto G as a guinea pig - and so far, he does not get hot, neither does the charger and he seems to charge faster than with my Nokia charger (Motorola does not supply a wall charger with the phone). In fact, both the charger and the phone to stay cooler than when I charge my 920 with my Nokia charger (though they don't get alarmingly hot).

Another question, the salesman said it's best to keep on charging even when the phone says 100%, as the phone has trouble measuring a full battery. This conflicts with what I have read and heard from my techie friends, that li-on batteries do not like to be full, but like to stay between 40%-60%. So, how bad was this salesman?
(source: Ask Ars: What is the best way to use a Li-ion battery? | Ars Technica).

Thanks for reading - as it's quite a story I wrote!

 

[Curtieson]

He is correct about the amps. The phone will only pull as much as it needs. The only time you will really run into issues is if you are working with different voltages (5 vs 12 vs 110/120).

Think about it this way...do you know how many Volts you have in your household plugs (or even in your car battery)? Most likely, you do know, or could quickly find out. Now, do you know how many amps?

Most phones are going to draw 1 A, in the past that was lower (500 mAs) but as they are becoming more powerful it is working its way up...and the reason your new charger puts out 2.1 As is because that is what tablets need these days.

 

[Adriaan NL]

He is correct about the amps. The phone will only pull as much as it needs. The only time you will really run into issues is if you are working with different voltages (5 vs 12 vs 110/120).

Think about it this way...do you know how many Volts you have in your household plugs (or even in your car battery)? Most likely, you do know, or could quickly find out. Now, do you know how many amps?

Most phones are going to draw 1 A, in the past that was lower (500 mAs) but as they are becoming more powerful it is working its way up...and the reason your new charger puts out 2.1 As is because that is what tablets need these days.

I don't know exactly what my household plugs offer. According to Wikipedia, Dutch household plugs offer around 230 volt and 35 or 40 amps. That's a bit higher than the numbers you mentioned... But I guess, like you say, the phone knows how much he needs, so he'll reject the rest of the power he doesn't need (which is a lot...)?

 

[C LaBelle]

Electricity is drawn, not pushed in. The 2.1 amps you see is the max rating, what the maximum amperage of the charger is, how much it could supply. It may even charge quicker now that it has more electricity to pull from. Think of it as a drinking straw, the smaller diameter the straw the harder it is to suck liquid through. A larger diameter straw will allow more liquid through, that's how amperage is.

 

[Adriaan NL]

Thanks for the responses! It's clearer now - these metaphors work well for non-techies and they're reassuring!

 

[c03105780]

Does anyone know the maximum number of amps the Nokia Lumia 920 will draw?

 

[PieterJan]

The first message says that the charger had, OEM/ official Nokia charger is also 5V, but only 1A(MP).
So it looks like the phone does not need more Ten 1A

 

[Curtieson]

I don't know exactly what my household plugs offer. According to Wikipedia, Dutch household plugs offer around 230 volt and 35 or 40 amps. That's a bit higher than the numbers you mentioned... But I guess, like you say, the phone knows how much he needs, so he'll reject the rest of the power he doesn't need (which is a lot...)?

Yea, I was quoting US stuff, we are much lower than Europe...[apparently American's are much more prone to sticking our hands into sockets and trying to kill ourselves? haha]. The others have also set up some good information for you, I think you get the idea now

Not sure that it matters...but just wanted to be clear...the phone will only pull as many Amps as it needs...but if you supply more Volts than it needs, that is when you burn things up. It is hard to accidentally supply the wrong voltage to something however, because companies just put different plugs on them. A 5V (cellphone) plug will be completely different than a 12V (car battery) cigarette lighter plug you'd use...and different still for an 18V (a laptop charger) and a 230V (household plug)... But yet you could have different devices plugged into each of those and all of them pulling 1 Amp.

And just for fun, you mentioned 'Power'...so remember that Power isn't Volts or Amperes...but rather BOTH. :smile:
Power (measured in Watts) is Volts times Amps

 

[xandros9]

Worth noting the stock charger for my 920 puts out 1.3 Amps.

 

[C LaBelle]

The first message says that the charger had, OEM/ official Nokia charger is also 5V, but only 1A(MP).
So it looks like the phone does not need more Ten 1A

Not exactly. It depends on the hardware limitations. I guess you could find a charger that was capable of supplying a good amount of amps (10 for example only) and put a multi-meter in line and then measure what the max amp draw is. Like Curtieson mentioned, you can't give it more volts, but more amps is fine. A cell phone shouldn't pull more than an amp or two.

*Warning* I'm going to geek out here for a second.

If you want to get real technical then a Li-po/Li-ion battery should not be charged at more than one amp per 1000 milliamps of capacity. So in the 920's case it has a 2000mah battery so a maximum of 2 amps should be used. Some chargers out there are 2.5 amps and those will be fine since the capacity of the battery is only 2000mah. In a case where the capacity is greater, for instance a 5000mah battery, a max charge rate of 5 amps should be used. However if you were to exceed 5amps then due to the higher capacity you risk over heating the battery. On a 2000mah battery you probably wouldn't have that problem.

 

[c03105780]

Which model of Nokia charger do you have? The charger which came with my 920 is the AC-16 and has an output of 1 amp.