Hello to all who want to help me and can. Have been a few days the thick me in my car to install an additional battery. only the worry I have is that if I can install the 2nd battery the lima can charge both batteries !!! have a 44 AH battery in my car. and a 45AH or a 60 AH lima in it. that both batteries are charged but even if the 1st battery is empty as it is in this winter the 2nd battery can use to start. otherwise for my hifi a nlage is used. when do I need a stronger lima ???????? How does the separation relay work ? How does the separation diode work ? or are there other options that are better ??????? and how do I have to secure the 2nd battery that can be excluded ? please help me thank your Mogli123 P.S. maybe I can help you with a topic at some point.