So, I am again considering a dual battery system. I have a 2012 Chevy Silverado 2500HD. If I am correct it has a 160 amp alternator.

Presently, the only addition I have done to the vehicle is a HAM Radio. Yaesu 8900.

I purchased a electric air horn from amazon and eventually going to install that I am positive that, that will not put me in the requirement of a second battery.
Amazon Link to horn
Link to video if interested in sound of it.

If I were to add a fridge, that might be pushing me closer to perhaps needing a dual battery maybe.

I have not installed any additional lights, though would like to.

Basic question, at what point is a secondary battery even needed.

If you add an isolator, it allows you to run accessories off the second battery with the engine off while preserving the capacity of the first for starting or other functions.

I did forget about that point. Thank you for bringing that up.  But for how long?

I could see that for lighting and setting up a camp area perhaps... Anything else, I would think would be isolated to not needing the vehicle battery power.



This has me thinking about whether or not there is a transfer switch for a vehicle to go from alternator power to solar power in reference to a refrigerator.

How long depends on the capacity of the battery, the size of the load, and how much capacity you can use (deep cycle vs standard starting battery.) You wouldn’t need a transfer switch, you could just add a solar charge controller to add solar capability.

Don’t have direct experience with running extra equipment from a car, but I have researched it a bunch because I want to add a fridge, radio, box fan and lights in the near future.

The main factor I see is, when will the devices be used?  While motor is running or while it is not.  And how often will the motor be ran?

If you are working devices while the alternator is working, then not (as big) a big deal.

If you are parking the car with the engine OFF for 100’s of hours and expect to have the fridge / lights running, then you need an extra battery and solar.

One member just posted up how he was running a fridge in a suv in CA heat.  I would use that experience as a base line for what you want to do.

A link perhaps?

yes

DC to DC charger

When you are at risk of running your primary battery down and might not be able to re-start your vehicle.

This is most likely to occur when drawing your battery when it is off via radio, winch, fridge, or whatever else you might have.

So in mine (2002 2500HD), my secondary battery can be isolated from the primary. In regular mode both batteries are connected, and both are getting charged. I can then isolate them, and run the second one down (winching, or most likely running fridge all day/night at a campsite, along with other things like chargers, radio etc), and still have a primary battery at 100% to start vehicle. At which point I un-isolate so the secondary can get re-charged.

this is basically the only reason IMO.

Here you go



https://www.ar15.com/forums/Outdoors/I-have-seen-this-solar-question-asked-over-the-years-and-in-many-threads-/17-700522/


https://www.ar15.com/forums/Outdoors/What-solar-setup-solar-panels-are-you-using-to-charge-your-electronics-and-batteries-/17-700267/

Thank you'll have to do some reading Wednesday