Radio memory wire options

[Stripes136]

Hi guys – I have a quick question that maybe someone can answer for me. I have read through a couple threads talking about the different options for running the memory wire of a radio to a power source.

I have a 48v to 12v converter that is running my accessories, however it powers on through the key switch. Does the radio memory wire need to run to exactly a 12V source? Would it fry the radio if it was running to a 16V or higher source? My initial thought was to run it to one or two of the 8V batteries, but I did not want the batteries to get out of sync. How much power does the memory use when the radio is off.

The other option was to buy an additional battery. Does anyone recommend a small rechargeable battery to run just the memory on the radio or will I constantly be charging it?

Thank you very much for all the help!