They do this by providing enough power for the the car accessories and car computer, so they don’t continuously draw current from the car battery when the car is off. As you can imagine, these chargers are very useful …especially if you go on a trip or leave your car unused for a while. They’re also useful if you go on a lot of short car trips (like to work and back each day) and never give your battery a chance to fully recharge. Repeatedly doing this will dramatically shorten your battery’s life – unless you use a car battery charger or interchange batteries, leaving one at home to fully charge. The most important thing to remember with this tip is …make sure you fully charge your car battery at least once a week because it will greatly increase the life of your battery. Do this with a charger, interchanging batteries …or just going on a car ride long enough to recharge the battery. Tip 6: Check your car battery’s water level Most car batteries indicate if there is a need for water. So check the car battery water level indicator regularly and if water is needed, refill the battery with distilled water (and that’s important, ONLY use distilled water to refill your car battery). View our Free Presentation to learn how to bring old batteries back to life again