How should I charge my phone ( avoid fast charging)? I've recently got a new Samsung Galaxy A5 (2016) running Android 6. It's great, but I'm not sure how to charge it properly.

By using the charger that came with the phone I get a notification saying "Fast Charging" and the phone heats up like crazy so it can shorten the life of the battery (although it does actually charge really quickly).

Alternatively I can use 3rd party chargers (none of which obviously suport fast charging), but many websites say it can harm the battery because they can be of really bad quality, so I don't like that option.

The best option I see is to charge it using my PC, but I can't have my PC everywhere I go and leaving it on overnight seems like an energy waste (no, my PC can't charge when it's off).

Disabling Fast Charging seems like a good idea, but since the Marshmalow update, the option is not in the settings anymore.

The text on the stock charger says:
Input: 100-240V 50-60 Hz 0.50 A 
Output: 9V DC 1.67A or 5V DC 2.0A

With all that in mind, what is the best way to charge my phone and do minimal damage to the battery in the long run?
I would recommend getting a Samsung travel adapter which outputs at only 5v.