DC to DC Charger, why?

[craigav]

Originally Posted by RGD615

Did you ever get your DC to DC charger installed? I am getting read install mine in my 2818 Greyhawk. Did you splice it into the wire on diagram between the solenoid and the mini breaker? This is a simple but confusing install. I want everything to work as it did before but only allow 20 amps to come from my alternator when the engine is running. Any advice would be welcomed. Richard

Check out the image in post 15, that is how I plan to install mine when I get around to doing it. Everything should work as it did before with wiring it the way I drew it. The picture is a bit small, let me know if it isn't large enough or clear where to connect into the circuit. ~CA

[RGD615]

With much appreciation to Mini4mw, bansai, craigav and Grumpy for sharing all their knowledge (and diagrams) regarding DC to DC Chargers. I am still "bumfusseled" after a day with the fluke meter and diagrams. Here is what I wrote to Jayco...just to see what happens:

I have a 2018 Jayco Greyhawk 29MVP. I have installed, in parallel, two 170 amp hour Lithium batteries and a 2000 watt PS Inverter.
I have a 20 amp DC to DC charger I want to install that will limit the charging amps from the alternator to the batteries to save wear and tear on the alternator.. However, I do not want to disrupt the charging systems that came installed on the coach that charge both the house and chassis batteries. For example…charging from the generator, shore power, or solar. Nor do I want to lose the use of my Aux Jump Start Button.
My question is where to tie into the existing wiring. I have followed the black, 4 awg wire with yellow tape, from the solenoid under the hood under to its connection the coach to the battery compartment thinking this is the wire carrying the charge for the alternator to the coach battery positive terminal. I tested amps at every connection with the engine off. It showed around 3.50 amps. My Victron Shunt showed – 2.10 amps being used. I start the engine the Victron Shunt shows 24.50 amps being put into the battery. My meter at the on the suspect wire showed 4.20 amps. An increase but, not what I expected.
Does the alternator send the amps all the way back under the bed to the charge controller and then back to the battery? Should the DC to DC charger be between the Charge Controller and the coach battery? I must say I am baffled by this one.
Help.