Every time I start my car the battery runes down
My car has an automatic transmission.
The alternator in your car charges your battery with the assistance from the voltage regulator which is something that regulates the amount of voltage being sent to the battery via the charging from the alternator. It’s function is to not over or under charge the battery, but to keep it at a specific and constant charge. When this is not working properly, this can cause the battery to be over or under charged often times resulting in the battery dying. I would recommend having a qualified mechanic, like one from YourMechanic, come to your home to diagnose your draining battery and help you repair it as necessary.