This would be my choice for using my Truck Alternator to also charge my deep cycle batteries. Please read up on how the BLUE SEA SI-ACR smart relay works and see if this may fit your application. The idea here is to NEVER discharge your truck start battery in the process... In the old days we would use diode based BATTERY ISOLATORS but the large DC VOLTAGE drop using high current diodes prohibits proper charging of deep cycle batteries. The difference in 13.6VDC verses 14.4VDC in DC charging voltage is crucial in charging deep cycle batteries in a short time three hour frame.
BLUE SEA SI-ACR SMART RELAYThis is what I was planning on doing for my unique situation of keeping a separate set of deep cycle batteries sitting in the back of my truck to run some high wattage two way radio equipment and also support my OFF-ROAD POPUP trailer operations when camping off the power grid. My battery requirements now is to use 150AH capacity batteries verses the 110AH shown in the drawing.
This is as far as I have got with this project with my worries being will I do harm to my truck alternator system. Never have looked up what size truck alternator I have or asked around if this is a good idea or not.
I see from the BLUE SEA APPLICATIONS this drawing I have is workable but I sure don't want to destroy my truck alternator in the process...
Just food for thought
Roy Ken
