Stand alone system for power in class A motorhome

[ampmike]

For various reasons I want to build a stand alone solar battery bank in my motorhome to essentionally use it as a power station. I do a lot of dispersed camping.

I intend to use 4 100 ah lifepo4 batteries that I already have.

I want to connect them to a 3000w Renogy inverter which I can plug my shore power cord into after I turn off my current converter.

I can charge the batteries with a 300watt solar panel that I already have.

While at home or at an RV park I can charge the batteries with a 30ah Victron battery charger.

I intend to use a battery selector switch to go back and forth if needed from the lithium bank to the house battery.

I have attached a picture of what my current plan is.

First will it work

Second suggestions are welcome.

 

[justinm001]

There's no point in using 1ga wire to the bus then 4/0 from bus to inverter.

If mixing battery types the shunt isn't going to help and the charger, solar, inverter are all going to need to be changed.

Grounding the battery neg bypasses the shunt.

Put a DC to DC charger and use one bank to charge the main bank.

 

[MisterSandals]

Second suggestions are welcome.

I think from your battery, thru an inverter to your RV shore power charger is quite wasteful with t least 2x 15% energy losses.

Put a DC to DC charger and use one bank to charge the main bank.

This is what i was thinking too. Add a pigtail to your RV battery bank so you can connect this easily and perhaps in a weather tight location or manner.

 

[ampmike]

There's no point in using 1ga wire to the bus then 4/0 from bus to inverter.

If mixing battery types the shunt isn't going to help and the charger, solar, inverter are all going to need to be changed.

Grounding the battery neg bypasses the shunt.

Put a DC to DC charger and use one bank to charge the main bank.

Renogy recommended those wire sizes
I am not mixing battery types this will be stand alone
If the battery is not grounded to the chassis how will 12v work when the inverter is off?
I do not want a dc-to-dc charger as the motorhome already has a battery control center that charges the house battery.

 

[ampmike]

I think from your battery, thru an inverter to your RV shore power charger is quite wasteful with t least 2x 15% energy losses.

This is what i was thinking too. Add a pigtail to your RV battery bank so you can connect this easily and perhaps in a weather tight location or manner.

How else will I get 110 to the motorhome without plugging the shore power to the inverter?

 

[justinm001]

Renogy recommended those wire sizes
I am not mixing battery types this will be stand alone
If the battery is not grounded to the chassis how will 12v work when the inverter is off?
I do not want a dc-to-dc charger as the motorhome already has a battery control center that charges the house battery.

They recommended what wire size? You show 1ga going from the batteries to the buss then 4/0 from buss to inverter. You can't pull more amps than the 1ga as that's the lowest.
You show the battery switch from house to lfp batteries

If you replace that A B switch with a DC to DC charger you'll then pull power from the lead acid to the lithium. Can turn it on or off as needed. This way lead acid charges lithium as does everything else so it can all have lithium profile.

 

[justinm001]

Battery ground needs to be AFTER shunt as shunt measures all neg power from/to battery

 

[ampmike]

They recommended what wire size? You show 1ga going from the batteries to the buss then 4/0 from buss to inverter. You can't pull more amps than the 1ga as that's the lowest.
You show the battery switch from house to lfp batteries

If you replace that A B switch with a DC to DC charger you'll then pull power from the lead acid to the lithium. Can turn it on or off as needed. This way lead acid charges lithium as does everything else so it can all have lithium profile.

1awg is .293 and 4/0 gauge is .460
I do not want to pull power from the LA battery

 

[ampmike]

Battery ground needs to be AFTER shunt as shunt measures all neg power from/to battery

so I need to do this?

 

[justinm001]

so I need to do this?

No the whole diagram is messed up and completely wrong. You need 1 wire from the pos and 1 from the neg of the battery bank nothing else. Neg to shunt then from shunt to bussbar then to ground and all sources. Nothing between batteries and shunt

 

[ampmike]

No the whole diagram is messed up and completely wrong. You need 1 wire from the pos and 1 from the neg of the battery bank nothing else. Neg to shunt then from shunt to bussbar then to ground and all sources. Nothing between batteries and shunt

I guess my drawing was confusing because I just copied it off my origin gal drawing. What I meant was just to move the shunt to the location between the chassis ground and the battery.

 

[justinm001]

I guess my drawing was confusing because I just copied it off my origin gal drawing. What I meant was just to move the shunt to the location between the chassis ground and the battery.

Only 1 wire from the battery bank on each side. Neg to shunt then shunt to bussbar and all loads on the bussbar.

 

[ampmike]

They recommended what wire size? You show 1ga going from the batteries to the buss then 4/0 from buss to inverter. You can't pull more amps than the 1ga as that's the lowest.
You show the battery switch from house to lfp batteries

If you replace that A B switch with a DC to DC charger you'll then pull power from the lead acid to the lithium. Can turn it on or off as needed. This way lead acid charges lithium as does everything else so it can all have lithium profile.

Another reason for not using the DC to DC charger is when the motorhome is running the alternator will try to charge the Lithium batteries too and if they are way down it over work the alternator.

 

[ampmike]

Only 1 wire from the battery bank on each side. Neg to shunt then shunt to bussbar and all loads on the bussbar.

How will I wire it so the motorhome gets 12 volt from the lithium bank and have the shunt for the battery monitor?

 

[ampmike]

How will I wire it so the motorhome gets 12 volt from the lithium bank and have the shunt for the battery monitor?

Is this now right?

 

[ampmike]

1awg is .293 and 4/0 gauge is .460
I do not want to pull power from the LA battery

I made a mistake Renogy said 1awg if I did this

 

[Supervstech]

I made a mistake Renogy said 1awg if I did this

This is better.

 

[Supervstech]

Or, you can change the #1 to 4/0

 

[Supervstech]

Is this now right?

You need another conductor from the house negative to the shunt.
The way this is drawn, negative energy flows through the chassis.

 

[ampmike]

You need another conductor from the house negative to the shunt.
The way this is drawn, negative energy flows through the chassis.

Isn't that the way all 12v loads work? If it did not there would be a hundred wires going to the negative cable?