Installing a 48V Renogy Inverter in a Cedar Creek Silverback: Wiring & Battery Choices

[Minky]

I am planning to install the Renogy 3500-watt solar inverter utilizing my existing RV hardware wherever feasible. I have outlined the following plan for the installation. I respectfully request that solar energy experts review it and provide feedback, along with detailed explanations where necessary. Thank you.

Wiring Schematic Description
Below is a textual description of the wiring schematic:

1. Shore Power to Surge Protector:
   • Shore power inlet (50A) → EMS-HW50C surge protector (6 AWG, L1, L2, N, G).
2. Surge Protector to Distribution Panel:
   • Surge protector output → AC input of distribution panel (6 AWG).
3. Distribution Panel to Inverter:
   • AC output from panel (dedicated 30A breaker) → Inverter AC input (10 AWG).
   • Inverter AC output → Sub-panel or panel AC bus (10 AWG, 50A breaker).
4. Battery to Inverter:
   • 48V 100Ah LiFePO4 battery → 100A disconnect switch → 100A Class T fuse → Inverter DC input (2/0 AWG).
5. DC-DC Converter:
   • Battery → 40A fuse → 48V to 12V DC-DC converter (10 AWG).
   • Converter output → DC fuse panel (8 AWG).
6. Solar Panels:
   • 4 × 400W panels (2S2P) → Combiner box → 30A breaker → Inverter PV input (8 AWG).
7. Grounding:
   • Battery negative, inverter, DC-DC converter, distribution panel, and surge protector grounded to RV chassis (8 AWG).
8. Monitoring:
   • Battery monitor shunt on battery negative, connected to display.

 

[Aussieguy]

I would have a 12v battery being charged by the dc-dc 48 to 12v
It will smooth out starting loads for slides etc
You do-dc won’t have to work hard to get slide or other high load started
————-

You need minimum of 60v so you’ll have to put panels 2s2p
If you can get 2 more panels 3s 2p may be better ?

 

[Minky]

I would have a 12v battery being charged by the dc-dc 48 to 12v
It will smooth out starting loads for slides etc
You do-dc won’t have to work hard to get slide or other high load started
————-

You need minimum of 60v so you’ll have to put panels 2s2p
If you can get 2 more panels 3s 2p may be better ?

I was initially considering using a 12v battery for the 12v system but the consumption of the12v AC to DC converter was very inefficient. Not sure if it would be considered as a loop? the 48v to 12v DC to DC is 40A not sure if that would make a difference with high loads? plus one less battery.

 

[Aussieguy]

you can always add the battery later if your heavy 12v loads can't get met..... by the 48-12v converter
just add a small battery ... does not have to be a full blown gigantic one

 

[Aussieguy]

turn OFF any AC 12v converter (power supply) ... not required
48v charging from shorepower or generator is usually achieved by using a inverter/charger or a all-in-one like a Victron or Eg4

if you connect generator/shorepower ... the inverter automatically switches to charging mode for the 48v battery
the small 48 to12v dc-dc converter will/can power 12v loads as they are turned on... will also keep the 12v battery charged

it will stop charging a 12v battery.... when the battery is full (battery simply stops taking it)
and will require very little power to keep it full...

there should be very little conversion losses
the battery is just another load to the little 48-12v converter and only is used to help overcome the heavy power requirements (in-rush loads) from jacks stabilizers and slides
it is NOT meant to act as a storage battery to increase capacity

 

[TacomaJoe]

If this is a trailer, you need to maintain 12V for the breakaway brake system.

 

[Aussieguy]

If this is a trailer, you need to maintain 12V for the breakaway brake system.

True ….. missed that
Been thinking of someone that was not going to tow on another post

But the 48 v battery will power the brakes through the dc-dc?

 

[Minky]

Yes, it’s a fifth wheel trailer.
After your recommendation on the 12v battery, it makes sense for the extra loads and the trailer brakes.
Disconnect the 12v converter.

Thanks you for your assistance.

 

[Minky]

is there any difference between RV solar panels compared to residential solar panels other than increased watts.

 

[Aussieguy]

Voltage
12v panels are usually smaller and the individual solar cells are wire into the panel to produce around 19v

Residential are wired to produce enough power for 24v system ….. normal production of around 33v

The bigger voltage good for larger residential application cause they can power inverters directly
Or they charge bigger battery banks 24 or 48v

24v / residential panels the terms are often interchanged… but means panels able to do 33 to 40 or more volts

 

[tomkatb]

You are trying to enter a system beyond most folks here.

Pretty much nothing existing is big enough. Higher voltage stuff is less common and more expensive. Bus conversions type.

For batteries you likely need much more. You will run out of storage at night.

Keep us posted. I thought about this in the past. A lot.

Went another route on our Hathaway.