The battery is the heart of your vehicle. A car is not much better than a rock with a door and windows if the battery is dead.
It's important to maintain the health of your battery, especially if you've purchased an expensive Optima or lightweight racing battery.
The number one important thing you can do to keep your battery healthy is... Don't kill it.
Letting a battery drain below its minimum power level permanently damages a battery. Even if you put the most expensive, bestest battery charger in the world on a over depleted battery, it will never regain 100% of it's original capacity.
The first step to keeping a battery healthy is to keep it fully charged. Many cars are equipped with voltage meters on the dash or in the driver information display.
If one isn't built into your car, most radar detectors can display vehicle voltage on their idle screen. Normal operating voltage should be between 13.5 and 14.8 volts (unless you have one of todays smart variable alternators like GM cars and trucks, they will run down the highway at lower output based on demand to maximize mpg and ramp up when needed).
If you see the voltage drop below 12 volts while the vehicle is running, you may have too many electrical devices turned on, or your alternator could be failing.