What type of tester can rate how many amps are in a car battery (12v)?
A car battery (or any other type, for that matter) doesn’t “contain” amperage; rather, they are capable of providing current (amperage) over time. Batteries are capable of providing different maximum current flow, but automotive batteries are typically rated as having a maximum cranking amperage (CA) for normal conditions and maximum cold cranking amperage (CCA) for winter conditions. To determine a battery’s capacity, you need a tester available from most auto parts places that puts a heavy load on the battery and reads the voltage the battery can maintain over a period of time with the load applied. I personally prefer to test a battery with a hydrometer. They’re cheap, and give a good indication of the battery’s condition. In particular, when taking a hydrometer reading, if one cell is significantly different from the rest, it’s a good indication that it’s battery replacement time.
