Adding a second house battery

[NTGOG1]

I installed a second house battery in my 2017 freedom elite RV every thing works just fine 12 volt and generator 110 but when I start the vehicle engine to runs awhile then dies and makes a solenoid clicking sound any help Im full time camping and kinda stuck

 

[Gary RV_Wizard]

Apparently you messed up something when you added the battery, so disconnect the add-on battery and see if the engine goes back to normal.

We can't guess what you did and you haven't given any clues.  You should have just wired the second 12v battery in parallel with the existing HOUSE battery (not chassis) and not changed any other wiring.  Did you?  Maybe post a photo of the alterations so we can see too?

 

[NTGOG1]

That's all I did then I removed the added batt and it dose the same swapped the new batt for the old and still the same Im thinking the solenoid may have went bad

 

[John From Detroit]

I noticed that solenoid clicking as well.. Question do you have an Intelletec Battery Control System?

I do not think your engine issue is related to the battery and I suspect the solenoid clicking may be normal... I have a theory but no way to test it.

Theory is this. When you first UNPLUG or SHut off engine you have a battery with a "Surface charge" that I measured at 13.6. This causes the Isolator relay to close joining the banks. but then the voltage goes down on the Higher battery causing it to drop out. and the cycle repeats till the surface charge is bleed off and the battery voltage drops below 13.2 or whatever the "Trigure" voltage is.

 

[Gary RV_Wizard]

Given what you say, I'm inclined to agree with John: the engine problem is unrelated.

However, the engine does need 12v power to run. If the alternator fails, it runs until the chassis battery goes dea, then it quits. Usually takes 30 minutes or so, though. The dash lights dim and go ut along with the engine dying.  Is that what happens?

What solenoid are you referring to?  The engine has a solenoid to engage the starter, but you started it ok, so that must be good.  Does your coach have a chassis battery disconnect solenoid?