RV Lithium location

[GottagoChris]

I get it now. Thanx

[GottagoChris]

I'm not sure what your saying. You run 6/5 SOOW from the 30 amp breaker to the inverter and then a separate 6/5 back to the same electrical panel?

[GottagoChris]

Originally Posted by astrocamper

Your batteries BMS is rated at 200 amps. Is that the continuous or surge rating? You will not be able to run your inverter at it's rated amperage with a 200 amp limit on the DC.

I used 4/0 DC cables and 650 amp bus bars on the parts of the DC circuit that involved the inverter/charger.

I kept my inverter in my front pass through storage and the batteries just behind the front pass through storage wall. I used stranded 6/5 SOOW cable between my trailers AC breaker panel and my inverter transfer switch. I ran the SOOW through flexible water tight conduit to protect it along the run. My Victron Energy 3000VA inverter/charger transfer switch is rated at 50 amps and the inverter/charger can do power assist combining input power plus inverter power to handle the larger surges. 8/5 cable would have been OK on the rating but I wanted to reduce voltage drop over the additional path.

My original converter was removed from the system. My original 30 amp power plug cable is routed to a 30 amp breaker, then to the inverter/charger transfer switch before returning to the original house circuit breaker panel.

I'm not sure what your saying. You run 6/5 wire from the 30 amp breaker to the inverter then run 6/5 wire back to the electrical panel?

[astrocamper]

Originally Posted by GottagoChris

I'm not sure what your saying. You run 6/5 wire from the 30 amp breaker to the inverter then run 6/5 wire back to the electrical panel?

I used 6/5 wire so I would only need one run from the original breaker panel to my pass through storage area. I put it in a grey flex conduit that runs on my inside floor next to the wall from my pass through storage wall to my kitchen cabinet area. This was easier than trying to run the conduit under the floor.

I spliced the hot and neutral from the outside 30 amp power plug to two of the 6/5 conductors. These would connect to the input my inverter/charger transfer switch after the hot goes through a 30 relay under software control. I connected the green conductor to the original trailer breaker ground bus. I connected the other two conductors on the 6/5 cable to the hot and neutral positions on the original breaker panel. These connect to the output of the inverter/charger transfer switch. The green conductor of the 6/5 wire are spliced to ground wires going to both the input and output ground positions of the transfer switch.

The output of the transfer switch actually goes to a new 30 amp breaker box with a 30 amp master breaker, a 30 amp breaker to the original breaker panel and a 20 amp breaker going to an external outlet on the sidewall of my trailer.

I could have used 8/5 SOOW and still been within specs.

The setup works very well. I have no problem running my air conditioner for hours off my solar and inverter/charger. My inverter/charger and the batteries have no problem with a 6000 watts of surge capacity.

[GottagoChris]

WOW! That's how I'm going to do it. Thank you soooooo much for the clarity.

[GottagoChris]

You stated "These would connect to the input on my inverter / charger transfer switch after the hot goes through a 30 relay under software control." Could you please clarify this step.

[astrocamper]

Originally Posted by GottagoChris

You stated "These would connect to the input on my inverter / charger transfer switch after the hot goes through a 30 relay under software control." Could you please clarify this step.

I have a Victron Energy Cerbo GX with two software controlled relays. Relay one is logically tied to generator start/stop. I use the battery SOC generator logic to control when the relay is opened and closed. I can also manually enable the relay when I am plugged into campground power which is not often. The Cerbo GX also logs all the data from my inverter/charger, BMV-712 and MPPT charge controllers and sends it to the cloud when Internet is available or uploads it later. I can review this data at the VE portal whenever I want. Relay 2 is just used to control a pair of 140mm fans to circulate air to my inverter/charger.

When my trailer is parked near my house I connect the outside 30 power plug to a RV outlet on the side of my house near the trailer. It is on a dedicated 30 amp circuit in my house. I have 30 amp outlet on the side of my trailer that is connected to the breaker panel after the inverter/charger transfer switch. This circuit goes back to my house and feeds my manual transfer switch in my house. I have 10 circuits on this transfer switch that provide lighting, refrigeration, furnace, networking and servers. This gives me some basic power in times of power outages. Each circuit has a Line/Off/Generator position so there is no danger of feeding power back to the power company.

I am using my trailers inverter/charger along with the trailer solar to power several of these circuits every day there is sunshine. The relay for the trailer power plug input to the inverter/generator transfer switch opens when my battery SOC reaches 73% and stays open until the battery SOC drops to 70% usually after the sunsets. Once the relay closes in the evening the power is passing from the house to the inverter/charger transfer switch and back to the home transfer switch.

I am shifting about 5 - 11 kilowatt hours per day from the power company to my trailers solar powered inverter/generator. I have also used the trailer as a UPS during power outages which gives me time to get gas and fire up the generator if the outage is scheduled to last a long time. The power assist function of the inverter/generator allows my Honda EU2200 to power more than the generator could power directly.

[GottagoChris]

Very well thought out! How do you recommend I deal with my manufacture installed hard wired converter to my AC panel. I would like to keep it available as a back up system. Can I leave the exterior 100ah AGM in place?

[astrocamper]

Just unplugged the factory installed converter and leave it in place for backup.

I would remove the AGM battery and move all the battery cables to the new system.

Label your DC cables before moving them to the new batteries.

[GottagoChris]

Originally Posted by astrocamper

Just unplugged the factory installed converter and leave it in place for backup.

I would remove the AGM battery and move all the battery cables to the new system.

Label your DC cables before moving them to the new batteries.

My factory installed converter is hard wired. Can I just turn the breaker off? Can I leave the battery and cables in place? Is connecting the factory battery cables to the lithium system safe?

[astrocamper]

Sure. If you have a dedicated breaker for the converter flip it off. I would also cover the breaker with electrical tape to remind you to leave it off. With the converter powered off there is no issue with the 12 volt cables to the converter being left in place.

If you are replacing the existing battery with LiFePO4 batteries, why would you leave the existing lead acid battery in place. The voltages and discharge rates will be different between the battery systems and they will not be compatible.

My comment about the labeling the cables is to be aware of how the existing cables are connected before replacing the battery. This will allow you to connect them to the LiFePO4 battery correctly. Y

[GottagoChris]

Originally Posted by astrocamper

Sure. If you have a dedicated breaker for the converter flip it off. I would also cover the breaker with electrical tape to remind you to leave it off. With the converter powered off there is no issue with the 12 volt cables to the converter being left in place.

If you are replacing the existing battery with LiFePO4 batteries, why would you leave the existing lead acid battery in place. The voltages and discharge rates will be different between the battery systems and they will not be compatible.

My comment about the labeling the cables is to be aware of how the existing cables are connected before replacing the battery. This will allow you to connect them to the LiFePO4 battery correctly. Y

I need to take a step back.

If the inverter/ charger were to fail would that mean the entire rv is dead? Including the backup converter. Somehow I thought it would be good to have a backup but the shore wiring is being diverted from the electrical panel. Doesn't the shore power go to a new designated 30amp breaker, which then goes directly to the inverter, then returns back to the electrical panel? Why would the existing battery cables be connect to the lithium batteries? I thought the existing converter is not compatible with lithiums.

I'm sorry but I'm just trying to get this right because my efforts to find somebody local to advise me falls on deaf ears because nobody seems to know anything about lithium systems, not even DC systems. I'm relying on interpreting what I am piecing together online. I do appreciate your patience.

[astrocamper]

My 120 volt power goes through my inverter/charger transfer switch. If the inverter/charger failed while I was traveling, I could use a screw driver and remove the inverter/charger transfer switch from the circuit. I would only do this if I was camping with full hookups and it was so hot air conditioning was required to enjoy the rest of the trip. 90% of the time I camp without hookups and can live with 12 volts only until I replaced my failed unit.

My 12 volt system would not be affected by the failure of the inverter/charger. I have 1440 watts of solar and I would have plenty to run everything I need. I would only loose the ability to run the microwave, toaster, blender, air conditioner.

It may be helpful for you to create a circuit diagram showing how you are going to modify your system. Until you are able to create a design and have someone else review it, you are probably not ready to make changes on your own.

Your existing converter/charger may not be optimal for your LiFePO4 batteries but it may work well enough as a backup even if it wasn't able to bring you LiFePO4 batteries to 100% state of charge. When the inverter/charger is functioning correctly you wouldn't be using the converter/charger.

[GottagoChris]

Originally Posted by astrocamper

My 120 volt power goes through my inverter/charger transfer switch. If the inverter/charger failed while I was traveling, I could use a screw driver and remove the inverter/charger transfer switch from the circuit. I would only do this if I was camping with full hookups and it was so hot air conditioning was required to enjoy the rest of the trip. 90% of the time I camp without hookups and can live with 12 volts only until I replaced my failed unit.

My 12 volt system would not be affected by the failure of the inverter/charger. I have 1440 watts of solar and I would have plenty to run everything I need. I would only loose the ability to run the microwave, toaster, blender, air conditioner.

It may be helpful for you to create a circuit diagram showing how you are going to modify your system. Until you are able to create a design and have someone else review it, you are probably not ready to make changes on your own.

Your existing converter/charger may not be optimal for your LiFePO4 batteries but it may work well enough as a backup even if it wasn't able to bring you LiFePO4 batteries to 100% state of charge. When the inverter/charger is functioning correctly you wouldn't be using the converter/charger.

Thank you for taking the time to share your expertise. I'm gaining confidence with this system.