In my vehicle, I'm wishing to install a separate 12V/20Ah battery to power electronics (network gear, cb radio, etc).
I was told to not run two different sized batteries as they would overcharge the smaller.
My goal is to have the smaller / aux battery charged while the engine/alternator are running. When the engine is off, the equipment of course would still be usable without killing my truck's main battery.
I have found a device (Automatic Charging Relay) that may help me. Am I wrong? Is there a safe way to accomplish my goals?
Blue Sea Systems SI-ACR Automatic Charging Relay
ExpertPower EXP12200 12/20Ah Battery