More amps = faster charge?

[darklide]

Does anyone know if you charge your phone like the Nexus 4 with more amps if the phone will charge faster? Or are out phones limited by the amount if amps they can charge by?

An example is Black Berries Premium Charger that puts out 1.8 amps. Will Will hat charge my nexus 4 above it's original 1.2 amp charger?

Thanks

 

[BecomingDeath]

Not necessarily. Phones are limited to the amount of amps they can take. If you use a charger with more amps the phone will only use the maximum it is allowed leaving any extra unused.

 

[bjacks12]

Unless I'm in a hurry, I like to charge any battery with the lowest amperage possible.....it's better for the battery IMO.

 

[funkylogik]

The kernel sets the maximum charge current that the phone will draw. Like on my phone, the default maximum charge current is 1A. The charger is 1.2A but unless you tweak the kernel to draw 1.2A, you only get 1A from it :thumbup:

 

[Medion]

I'm just going to expand on what was said here.

Phones can have either a hardware limitation, software limitation, or both when it comes to charging. A perfect example of this is the Galaxy S2 GT-I9100 model. It comes with a Samsung charger rated at 0.7A (700mAH). The kernel is limited to a charging rate of 600mAH, just better than PC USB. So, a few of us dicked around with the kernel, and by removing the limitation, we find that the S2 also has a hardware limitation of 650mAH, meaning that we could barely speed it up.

Now, the S4 has a similar, but more complex issue. It ships with a 2A (2,000mAH) charger, but it has never been observed to charge at that rate. If you use the cable that it shipped with, and the charger that it shipped with, it will charge at 1.3A. If you use another other charger and/or cable (other than replacement OEM), it will charge at 500mAH. It may charge at a rate in between, but it depends on what it detects from the charger and the cable.

The reason for this, without getting too technical, is that the MicroUSB uses a standard where two contacts are shorted to denote AC. So, the phone looks for this short to determine if it charges via USB (500mAH), or AC (max allowed by hardware/kernel). Apple uses a different way to detect this, meaning that an iPhone will charge at 500mAH on ANY non-Apple charger. Samsung has added a third way, and it's more complex than Apple's standard (though it still works with standard USB/MicroUSB). As a result, you need perfect conditions for a Galaxy S4 to suck 1.3A from that 2A charger.

Long story short, using a higher amperage charger may or may not charge your phone any faster. The best answer is to use OEM equipment. Using generic equipment may actually charge your phone slower despite what it's rated at, especially if you're using an Apple or Samsung device. And if your OEM didn't place a limitation on charging speed? You can very well damage or shorten the service life of your battery.

EDIT: Repeatable test (partial source)

 

[funkylogik]

^^ nah you explained it well man. This is why samsungs will charge slower from the USB on a computer when using a data cable compared to using a charging cable with just two wires in it and the two pins shorted :thumbup:
Also, with the s3 anyway (and i dont understand how this works), it "knows when it "thinks" its charging from a damaged cable and drasticly drops the charge current but it seems to be over sensitive. It must be a kernel thing because it can be disabled in some custom kernels
Sorry, bit off topic lol :beer:

 

[darklide]

What is the maximum the Nexus 4 charges at? Any kernals that change that?

 

[funkylogik]

I honestly dont know but its maximum is probably no more than what the stock charger puts out :thumbup: just dont want you wasting money. There are play store apps that show you the charge currents. Most dont work on samsung phones but the N4 should be fine :thumbup:

 

[chanchan05]

Honestly, I'd suggest to not tamper. At least that's what an engineer advised me.

 

[Harry2]

What is the maximum the Nexus 4 charges at? Any kernals that change that?

For to measure the max charging amperage you could use a battery monitor like 'Battery Monitor Widget' which shows your the charging amperage even in a graph by time.

Note, the charger has to supply amperage for to charge the battery AND to supply the actual needs of the phone's electronic.
So because the total amperage of the phone is higher than the max charging amperage, the charger's capacity of amperage has to be higher too.

Harry

 

[ImperialJohn]

I've discovered my own phone only takes what it needs so I guess it has some sort of inbuilt charge controller to protect the battery and won't take the full 2A that my USB plug is capable of delivering.

 

[Harry2]

I've discovered my own phone only takes what it needs so I guess it has some sort of inbuilt charge controller to protect the battery and won't take the full 2A that my USB plug is capable of delivering.

You'd use the remaining amperage if you're using the phone while charging

Harry

 

[nickdalzell]

if you use a charger with a different amp rating than the phone/tablet was designed often you get a notification about improper charger or Samsung's infamous 'Unable to charge non-supported battery' message. other devices, similar to iOS devices, if using an unapproved or improperly-rated charger, just default to an extremely slow charge rate. as of yet, none of my latest devices will charge *period* from a car charger. they display the 'charging' symbol but the battery life just continues to drain, albeit slower than it would normally.

 

[Harry2]

You might try HTC's car charger C300, it is capable of 2A and has modified data lines, on the charger' USB port and on its cable's microUSB connector.

Harry

 

[Medion]

You'd use the remaining amperage if you're using the phone while charging

Harry

In my experiments, this is not always true. I tested the heck out of this with the HTC Droid Incredible, and here is what was happening.

The battery completes the circuit. Try using a phone plugged in with the battery removed. It doesn't work. So, the power flows from the charger into the battery, while the phone draws from the battery. The phone never draws directly from AC, and the battery does not charge any faster when in use. In fact, during heavy usage scenarios, it is possible for your phone to still discharge while plugged in. Doesn't happen as much these days with the 28/32nm chips, but it was blatantly obvious on ye olde Incredible or OG Droid with their 65nm chips.

In fact, using your phone while charging is generally a bad idea. This simultaneous push/pull can shorten the serviceable live of your battery, mainly due to the drastic increase in temperature. It's alright for quick, general tasks. But if you do as I do, using your phone for GPS/Navigation, at full screen brightness, with the phone plugged in, well, don't expect your batteries to last very long Mine die in 9-12 months on average. A new battery every year is a small price to pay for the functionality that I need, but it's also why I tend to avoid phones where you cannot replace the battery.

 

[Harry2]

... So, the power flows from the charger into the battery, while the phone draws from the battery....

This also might not always true ... I think the phone draws from the battery and the charger.
And shutting off a phone without battery is a protecting move.

Some times ago I directly measured on my HTC Desire's microUSB port the amperage while charging and running an app.
At the same time I recorded the battery's charging amperage with a battery monitor app.
After disconnecting the charger the battery monitor has recorded the battery's discharging amperage.
The sum of charging and discharging amperage was about the same amount of amperage that had flowed in the phone's microUSB port while charging.

So I think my stock 1A charger has a little reseve amperage while charging ... for delivering the phone's electronic ... but not enough reserve if a powerful navigation is running while charging. The amperage used by the navigation would lessen the part of amperage for the charging ... so you're right.

I haven't tried it with a 2A charger ... and to be honest I'd not put money on that it would improve the charging drastically while running the navigation ... not until I've measured it

Harry

 

[funkylogik]

I havent tried it on my s3 (cba taking the case off lol) but ive had an android phone that kept running if you pulled the battery while charging :thumbup:

 

[bcrichster]

As an electrician and having electronics knowledge, it's been a proven fact that charging batteries at a higher amperage/rate CAN in some instances charge it faster, but also seriously shorten it's power reserve capabilities if not actually burn them up. Garbage. Unfortunately, I've learned the hard way doing experiments or being foolish