How do I properly maintain the battery of my Audi A2?

My Audi A2's battery doesn't seem to be holding a charge as long as it used to. What steps can I take to properly maintain the battery and prolong its lifespan?

Regularly check the battery's fluid levels and top off with distilled water if necessary. Avoid letting the battery completely drain, as this can damage it. Installing a battery tender or trickle charger when the car is not in use can also help maintain the battery's charge.

Avoid using electronic components like lights, stereos, and air conditioning when the engine is off to prevent draining the battery. If you plan on storing the car for an extended period, disconnect the battery to prevent drainage.

Consider investing in a high-quality battery from a reputable brand, as these tend to have longer lifespans and require less maintenance.