Running Xcvr from Secondary Battery

[WA2WMR]

I would like to install a Yaesu xcvr rated at 23 amps in transmit in my new car. The cigarette lighter sockets inside the cabin are only rated at 10 amps. Getting through the firewall is problematic (read not acceptable). I do have storage locations where I could keep a second battery. What I am looking to do is charge the second battery from one of the cigarette lighter sockets. Is it possible to set up something that would charge the battery from the cigarette lighter but when transmitting draw only from the battery?

[WA3LTJ]

This is called a charge controller. It is most commonly in use for solar chargers. I won't embarrass myself by giving you some bad practical advice. Others on this board (or on the Elmer's section) can give you good advice. 

[WA2WMR]

Thank you. I will post it there. I will definitely look into a charge controller.