Here is a chart of the average weight range for common car battery sizes: Keep in mind that this chart is for reference only, and the actual weight of a battery may vary depending on the brand and type. It's always bestto check the manufacturer's specifications before purchasing a replacement battery. The weight of a carbattery can vary depending on the type, size, and brand. On average, a standard car battery weighs around 40 to 60 pounds. Most car batteries are 12V, so the weight range we discussed earlier applies to these batteries as well. However, it's worth noting that there are different types of 12V batteries, including conventional flooded batteries, AGM (Absorbent. To calculate the weight of a battery, you need to know its capacity (Ah) and the specific gravityof the electrolyte. The formula is as follows:. Car batteries are heavy because they contain lead-acid cells that produce electricity through a chemical reaction. These cells are made up of lead plates and an electrolyte solution.