Can I pluggin any phone or tablet designed for 1A to a 2.4A ( fast charge mode) power source?

[Metamorf]

Some do support fast charging, others I am not sure. Can it cause harm?

 

[SpookDroid]

Nope. Charger will default to the 5V standard charging (if it supported Quick or Fast Charging... If not it's already at that level) and your tablet won't draw more current than what it supports.

 

[Metamorf]

Thanks friend!

 

[Mooncatt]

Yes, you can use it but it will not charge any faster. Since you mentioned 1A and 2.4A rates, I'm guessing you're not talking about the various multi-voltage systems out there like Qualcomm's "Quick Charge" setup.

All standard chargers are rated at 5V and various amperage ratings. Even when using a higher current charger, it's the phone that determines how much current to pull from it. If the phone is only designed for 1A, then it'll pull a max of 1A from any charger rated AT LEAST 1A (a weaker charger would only allow that lower rate).

Multi-voltage systems like Quick Charge have a default safeguard that falls back to standard 5V charging. They have to negotiate with the phone to determine the proper charging voltages and current. If the phone can't perform that negotiation, then it'll just get standard charged.

Given the price of chargers these days, I say get the strongest one you can. It won't cost much more than a minimum one for your phone, but will last you longer with some future proofing.

 

[jamesmehraa]

You can use it but if your phone does not support fast charging then it will not charge your phone quickly instead, it will charge at normal speed.

 

[Ry]

Your device should/will default to the fastest charging that it can properly handle.