VARTA Auxiliary batteries provide electrical components with seamless functionality. Modern cars consume a significant amount of electricity. Therefore, these cars with a combustion engine often come with two batteries: a regular 12 volt starter battery and an auxiliary battery. Thus, when it comes to replacing a weak or defective auxiliary battery, it is vital to rely on a high performing substitution. Furthermore, it is important to always replace an AGM auxiliary battery with another AGM auxiliary battery to avoid the risk of malfunctions and car breakdown.