# Will a high current (3.1A) destroy smartphone battery?

• Psinter

#### Psinter

Will a high current destroy my smartphone battery?

I know very little about batteries, but I'm getting really annoyed at having to wait 8 hours for my phone battery to charge (it's a 6 year old smartphone). So I was thinking of raising the 2.1A output of the charger to 3.1A without raising the voltage. I'm willing to experiment, I mean, this is so old I'm not afraid to break it. But first, I want to hear some possible theoretical answers.

The specs of my battery are: Li-ion 3.7V 1500mAh 5.6Wh.

My questions are: any chances of this destroying the battery? Or is there usually like a circuit that stalls the current at a specific level on smartphones and instead of destroying the battery I destroy the circuit and render the phone unable to charge the battery, but still be able to charge the battery with an off-phone charger?

I don't know about smartphone batteries but I have some regular 1.5V rechargeables that I use in one of my cameras and after I charged a couple of sets a couple of times with a "high-speed" charger (1/2 hour instead of hours) the batteries would no longer take a charge and had to be tossed.

Manufacturers know how impatient users are to have their phone recharge. My thoughts are that the designer settled on that charge time as a safe compromise between speedy recharge and battery damage. If he could have safely halved the recharge time, he undoubtedly would have!

Will a high current destroy my smartphone battery?
Yes it will. If you are lucky, it is just the battery and not the whole smartphone or even the whole house.
I know very little about batteries
Li-Ion batteries are tricky to handle correctly. Your smartphone charger can do it if you do not modify it.
So I was thinking of raising the 2.1A output of the charger to 3.1A without raising the voltage.
That does not work.

Or is there usually like a circuit that stalls the current at a specific level on smartphones and instead of destroying the battery I destroy the circuit and render the phone unable to charge the battery, but still be able to charge the battery with an off-phone charger?

Yes, phones have inbuilt charging circuits that prevent over current. You will not be able to damage it unless you input too much voltage. The current the charger is capable of supplying is, above the greatest current the circuit will allow, irrelevant.
You may be able to find a new battery for a few bucks on ebay or sim. That's what I do when my phones batteries have started to lose capacity/increased charge time. Makes a world of difference.

You may be able to find a new battery for a few bucks on ebay or sim. That's what I do when my phones batteries have started to lose capacity/increased charge time. Makes a world of difference.
I suppose I'll go with this one then. After all it is just \$15 USD.

Thanks everyone for letting me know that yes under these circumstances.

The charging of a smartphone battery is controlled by the charger in the phone. It will charge at its correct current regardless of the amperage rating of the charger connected to it. The amperage rating of a charger only indicates what it is capable of supplying if the device's internal charger wants it. Changing the charger to a higher amperage charger will likely have no effect.

Now, there is one exception. For example a tablet might be able to make use of 2.1A from a beefy charger, but will work fine connected (and charge slower) if connected to a 500ma charger. Chances are that the phone can't even make use of the 2.1A you have available. Li-ion batteries generally charge at 1C or below, which is 1.2A in your case.

Generally a long charge time generally indicates the battery is taking a long time to get through the constant voltage phase of the charge cycle because it is drawing a current that is above the charge termination current. I expect it is actually as charged as it is going to get well before 8 hours. Give it 4 hours and see if it lasts just as long.