Many people often get confused by higher amp rated or higher watt charger and start thinking either it is safe or not. For example using a 90 watt charger with 65 watt power model.
The simple answer is that it is 100% safe. The Amps rating on charger basically is the information about the amount of power from zero-xxx maximum it can supply to input device. Higher amp means stronger and power full charger.
Your laptop will only draw as much amperage as it needs to perform whatever it’s doing from the total maximum capacity of current the power supply can provide. The higher wattage charger doesn’t necessarily use all those watts unless called for so you’ve got a safety zone – a reserve, like horsepower in a car, it’s there but you use just what you need so as long as you replace your charger with one capable of providing same amps as your laptop requires or higher, you’ll be fine. The voltage must be the same anyway.
If for some reason your replacement charger has a lower than required amperage rating, your charger will start getting overheated and might stop functioning at one stage.
Finally avoid buying non branded cheap replacement power adapters. Those companies often misrepresent which mean charger might not be able to produce exactly same amps power which they claimed or labelled. Plus circuit board will be poorly manufactured too with low quality parts. As a result those types of adaptors get overheated fast or start making noises and get flat quickly.