A 65-watt charger will not force 65 watts into your phone
Your phone picks its power level after a quick negotiation with the charger.
anker.com · Budowa ładowarki do telefonu – schemat i zasada działania - Anker EUPlug a phone built for 25 watts into a 65-watt charger, and it still takes about 25 watts at most.
The wattage on the box is what the charger can supply, not what your phone will take. With the common fast-charging system called USB Power Delivery, the charger tells the phone what power levels it can offer, and the phone requests the one it wants. A working, compatible charger with a higher power rating should not harm the phone for that reason alone.
An added feature, known as PPS, lets the phone and charger adjust voltage within a set range. Once they agree, the phone's charging circuit adjusts voltage and current to suit the battery, factoring in temperature and charge level. That is why power usually falls near the end of a charge.
The cable can limit the power as well, and some of the incoming energy also runs the phone itself while it charges.
Questions people ask
Will a bigger charger charge my phone faster?
No. If your phone tops out at 25 watts, a 65-watt charger still delivers about 25 watts at most. You may charge faster than with a weak old charger, but you will not exceed what your phone was designed to take.
Can the wrong cable slow charging?
Yes. Even with a capable charger and phone, a thin, damaged, or low-rated cable can limit power. Some fast-charging modes require a 5-amp cable with a tiny chip inside that reports what the cable can handle.
Why does my phone get warm and slow down near the end?
Some warmth is normal, especially during fast charging, because some energy turns to heat during conversion. Near the end, the phone's charging circuit accounts for temperature and charge level, so power usually drops.