I bought new phone with new charger. (100w)

Can old handphone use new charger to charge? Will it be harmful?

It is not harmful, totally fine.

This post has been edited by tvcat: Aug 17 2023, 06:06 AM

If the phone only take 20w, 100w charger is useless.

Ze phone will tell the charger that it needs only 20watt and won't take more

Simple explanation

Yes. No.

The charging current depends on the phone, not the charger. So, no problem. Higher power charger will not make your old phone charged faster either.

No problemo la.

I'm using a ThinkPad 65W charger to charge all my Type C phones from 2018 onwards. No problems as Type C devices will negotiate with each other for the correct voltage and current.

Yes can use.
No harm will come to phone.

same theory as tnb supply ur house 32amp fuse
about 7k watt
but u charge handphone 20w only
can support or not u tell me

this. Very good long wire sturdy too, if spoil got 2nd hand replacement easy

TBH that’s what charger is for. Another name for charger is adapter, as the role of it is to adapt your 240V AC into the minuscule 5V DC.

The actual output from charger is only 5V (or 20V in 100W PD charger sense) DC.

Now back on TS’ query. The main concern here is the Voltage. Legacy phones only support 5V charging, eventually Qualcomm quick charge came out and mainstream started supporting 9V and eventually now 12V, 15V or even 20V. If the 100W charger have 5V modes, I don’t see why it wouldn’t work. Likewise, if it didn’t have 5V mode, your phone is also not that dumb to trigger the higher voltage mode than it’s designed to take. Both sides actually will communicate with each other and engage protocols (PD/QC/FastCharging/SuperCharge and etc, each brands have own protocols) check (charger, device and cable all need to comply with said protocols) before able to engage the high wattage charging.

This post has been edited by msacras: Aug 17 2023, 12:19 PM

in short, u can use it on older phone, but the older phone wont charge faster due to limitation

Dirt cheap too. Many laptop sellers unaware it can be used for charging any Type C devices too. Cheaper than buying new Ugreen or Baseus chargers.

I use 25w charger to charge phone that not support fast charging, ok je
Phone no damage