Is a DC to DC Charger Really Needed?

[guber1]

dkoldman

i have read that the coach battery is charged by the alternator. Doing the wiring to put in the victron i don't see it. Would you know how that is. It seems if that's the case it should be disabled.

[Ray,IN]

FWIW, Trombetta is a brand name, not a type of device. It is a 12V solenoid rated for high (200) amperage.

[dkoldman]

Originally Posted by guber1

dkoldman

i have read that the coach battery is charged by the alternator. Doing the wiring to put in the victron i don't see it. Would you know how that is. It seems if that's the case it should be disabled.

I am not sure I follow?

Yes by default the coach battery is charged by the alternator as well as the house batteries.

That is and was the purpose of why this thread was created. No need to read it all but if you start at the beginning you can see where I had no idea if i even needed a DC to DC, I then proceed with all of what I learned step by step.

I put in a switch so I can disable or reenable by trombetta. It is in post #58.

You say Victron but I have no idea which Victron you got? They have many models. Mine has nothing to do with the alternator directly with respect of installation. I explain my install up above.

At this moment since I have Lithium batteries my Trombetta is disabled but that has nothing to do with alternator still charging the Chassis battery. I didn't touch that nor will you need to.

[guber1]

Okay let me try this again. I am also putting in a DC to DC charger and a lithium battery like what you are doing. My understanding was that this was necessary to properly charge the house battery when in motion. In doing so I don't see where the house battery gets charged from the alternator. The manual I pulled offline says "House batteries are automatically charged by
the chassis alternator while the engine is running"
I was curious how this was achieved and if it should be done away with.

[dkoldman]

Originally Posted by guber1

Okay let me try this again. I am also putting in a DC to DC charger and a lithium battery like what you are doing. My understanding was that this was necessary to properly charge the house battery when in motion. In doing so I don't see where the house battery gets charged from the alternator. The manual I pulled offline says "House batteries are automatically charged by
the chassis alternator while the engine is running"
I was curious how this was achieved and if it should be done away with.

Thing 1.
You don't have to have a DC2DC to charge house batteries when driving the RV, yes it is the method I chose, but there are other options. I am just making that point clear because I am not sure of context of your statement. I am assuming you simply want to use the DC2DC method to charge house batteries as a preference.

Thing 2.
You say "In doing so I don't see where the house battery gets charged from the alternator."

Are you talking about the way the coach came from WBGO?
Are you talking about how you will wire with your new DC2DC?

Thing 3.
You say " The manual I pulled offline says "House batteries are automatically charged by
the chassis alternator while the engine is running"

This is true in almost any OEM standard configuration. If your house batteries are not charging while engine is running you likely have a defective part (solenoid) or miswiring.

Thing 4.
I am not sure of this question
I was curious how this was achieved and if it should be done away with.


All I did was the below, and I did it over time one step at a time, very simple so kind of confused at what your concern is?

1. Installed a safety switch to turn my Trombetta ON/OFF
2. Installed a new Progressive Dynamics Converters
3. Installed a Victron Orion XS 50amp DC2DC Charger
4. Installed a 300ah Lithium Battery

With all of that my house batteries still charge when the engine is running just like before. The only difference is the max current from alternator in my setup is 50amps. Whether I needed to do that is a matter of who you ask. Clearly I think it is the best, safest approach for my F-53 for my 29ve given I wanted to go to Lithium batteries.

[guber1]

My question is how is the house battery being charged. When I check the voltage with the engine running i get 14+ volts on the chassis battery and the newly installed lithium shows battery voltage at 13.3.

[dkoldman]

Originally Posted by guber1

My question is how is the house battery being charged. When I check the voltage with the engine running i get 14+ volts on the chassis battery and the newly installed lithium shows battery voltage at 13.3.

If you are asking from OEM WBGO install; it should be through the Trombetta. That is what I have been telling I put a switch on to have the option to disable so that it will NOT charge my House batteries.

Also as I said above as part of Thing 3
If your house batteries are not charging while engine is running you likely have a defective part (solenoid) or miswiring.

Ironically, if your Trombetta does not work and you do install a DC2DC you will not need it anyway. I kept mine because I can turn it on whenever I want to use the Emergency Start and/or if I ever need to go back to AGM or another type of house battery.

[guber1]

Okay I guess I misunderstood the use of the trombetta. I thought it's main function was to join the chassis battery and the house battery for emergency start. I didn't realize it also somehow Joined the battery banks when the engine was running.

[dkoldman]

Originally Posted by guber1

Okay I guess I misunderstood the use of the trombetta. I thought it's main function was to join the chassis battery and the house battery for emergency start. I didn't realize it also somehow Joined the battery banks when the engine was running.

It does both. Pull the 29ve DC drawing for your coach. When the ignition is turned on it powers the yellow wire that feed that trombetta that triggers the contact (solenoid) Trombetta to close. If engine is running it charges both battery banks, it also allows for Emergency start function.

My switch I installed above effectively can disable both functions. However, if in an emergency, I can simply re-enable that switch so it is back to the WBGO OEM install, then I can go and hold my Emergency Start, start my chassis engine with help from House battery, and then go back outside to disable the switch.

But you suggest a different problem, you are implying / saying right now, with your OEM install, your House batteries do not charge when Engine is running? That SHOULD NOT be the case.

Forget Lithium, DC2DC etc.

For 5 years I have run my fridge off the inverter of any trip as long as the engine is running. (Yes, I rewired my Absorption fridge to run off the inverter) It is one of the best things I have done. I switch to Propane or SP when I get to a stop longer than 2 hours; so the house battery does not drain.

Now back to Lithium, DC2DC, I do the same thing today, but I have disabled the the Trombetta (added simple red emergency switch) from charging and allow my Vitron Orion XS charge. Max draw current is 50 amps. I have 300ah of Lithium, so I prefer to use the DC2DC as to not risk possible overheating of alternator. I also installed new Converter. Technically, I may not have had to do either, but I only spent $500 total and then another $400 for 300ah battery.