What will happen if I use 33W charger in 10W phone ?

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I bought POCO M2 Pro, which comes with 33W adapter. 11V * 3A = 33W. I have an old Redmi Note 4 device, which uses 5v * 2A = 10W adapter to charge. What will happen if I connect my 10W phone into 33W adapter ?

33W charger Description given below.

WhatsApp Image 2020-09-13 at 2.58.14 PM.jpeg
 

Sushubh

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it would not blow out your device. poorly designed charging circuits in phones might cause issues. but modern phones with properly spec usb charging ports should handle even laptop chargers just fine. some phones like Samsung even have a software settings that can take less charge than supported for slow charging.



Basically... Redmi phones should be fine. But since Note 4 is quite old these days, it might not be a good idea to regularly charge it with a powerful charger. I imagine it uses a micro-usb port? USB-C ports can be a bit risky because a lot of companies do their own implementation which is not spec compliant.
 
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No of course not. It's perfectly safe. Your phone will only take the current it needs. You just need to make sure the voltage is same.

Imagine electricity as a pipe, the current is it's width. Your phone's charging circuit is the tap and the end of it, you battery receives electricity from the tap.

You can make the pipe as large as possible, the water flow will still be decided by the pipe's opening at the end. If your charging circuit is good, it'll be fine. I've seen people mod RN4 for 18W fast chargers as well.

Now imagine voltage as the pressure of water running through the pipe. Higher than normal voltage could damage the phone, like those water cannons used by the police, those can hurt.

TLDR: Make sure charger is of 5V, current doesn't matter.
 


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Only higher electric potential (V) will cause damage to a device.
The current mentioned in any kind of power supply (a phone charger here) is the max current it can provide, not the current it will necessary provide.
Current is function of potential difference and resistance of the circuit, so a fixed resistance (at any point in the charging) and voltage will consume only a fixed current.

TLDR - no, it doesn't matter unless that charger is faulty.
 
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249
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Pathanamthitta, Kerala
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BSNL FTTH | BSNL ADSL | Airtel 4G
No of course not. It's perfectly safe. Your phone will only take the current it needs. You just need to make sure the voltage is ..

...ke sure charger is of 5V, current doesn't matter.
Adding to the earlier post, Xiaomi's 2A chargers I've seen provide more than 2A sometimes and does get quite warm. Their phone's charging circuits might need more than just 2A. Your Poco charger can switch to 5V3A for your phone. It could use upto 2500mA based on some findings from Redmi Note 4 group's I've been in.

You can use it, it's perfectly fine, people have been doing it for a long time. Since it is an old phone with weared out battery, I'd still advice not do it all the time, if you want your battery to last a couple more years.
 
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The rated current of almost any good quality charger is generally conservative, a good quality 2A charger can and does provide more than 2A (generally 2.1-2.5A) and most phones can and does take more than 2A, at least in the initial stages of charging (low battery percentage) thus the higher than rated charging rate.