Do I have to buy a special charger for LiFePO4 batteries?

You do not need a special charger to charge your LFP deep cycle battery. As I mentioned above the battery prefers to bulk charge at 14.4 volts and float at 13.6 volts. Most standard chargers can handle these settings. There are some made for lithium chargers available on our store page and they will charge faster than a regular charger in most cases.