Looking for suggestions on the solar system setup for a cabover camper

[AZLance]

Hi everyone,
I'm setting up a solar system for my cabover camper, and I have a few questions about setting up the solar system in the camper, primarily regarding the wiring and fusing of the system. I have the following components:

- 190W Rich Solar panel
- Victron MPPT 100/15 charge controller
- IP22 charger for charging when on shore power
- Victron Orion TR 12/12-30 DC-to-DC converter for charging from the truck alternator
- 12V, 100Ah Battleborn LiFePO4 battery
- Victron Phoenix 12/375 DC-AC Inverter
- Victron Bluetooth smart battery sense (not shown in the schematics)

The devices that will be powered from this system are:
- From the inverter: only oxygen generator (rated at 100W)
- From 12V DC :

• Lights
• Water pump
• Fan/pilot for the gas heater
• Pilot for the gas fridge (maybe the fridge itself, not sure what is the consumption)
• All alarms (gas, fire, CO)

- AC will only be powered when on shore power.

I'm planning to install positive and negative busbars in the battery compartment and connect the positive from the battery to the busbar using 60A MEGA fuse and AWG6 wire. The solar panel input to MPPT will be fused with 20A inline circuit breaker, and all wires are AWG10. The inverter will be fused with a 40A circuit breaker on AWG8 wire. A few questions that I have for the esteemed members of the community are:

1. Should the inputs from IP22 and Orion TR to the battery also be fused? Both put out 30A charging current, if they do, I assume 40A fuse would work?
2. Is 60A MEGA fuse for the battery positive terminal too small? Looking at the inverter, it is rated for 375W which divided by 12V is 31.25A, but the manual says that it can support peak 700W, which is almost 60A, so both the inverter and battery fuse may be undersized in the schematics.
3. I planned to connect OrionTR and IP22 at a location close to where the 7-pin cable comes into the camper. Can MPPT output be connected to the same place, or should it go on the busbar close to the battery? My logic is that I will either charge the battery from the shore power, or from the truck, but never from both at the same time. Solar on the other hand will charge continuously during the day, so I would have two charging sources, which also brings up a question if AWG6 cable should be thicker and if they need to be fused should the fuse take into account maximum output of IP22/Orion and MPPT (45amps)?
4. Anything else that I'm missing/have overlooked?

I would really appreciate all your suggestions/corrections to help me connect all of the components!
-Darko

 

[Bob B]

First thing I would recommend is to add a separate power line from the truck to the camper ... using Anderson plugs or similar. I think the Lance plug has better power handling capability than a standard 7 pin connector, but I wouldn't rely on it to handle the current.
I don't know what the current spec is on the Lance plug .... maybe someone else does.

 

[AZLance]

First thing I would recommend is to add a separate power line from the truck to the camper ... using Anderson plugs or similar. I think the Lance plug has better power handling capability than a standard 7 pin connector, but I wouldn't rely on it to handle the current.
I don't know what the current spec is on the Lance plug .... maybe someone else does.

Thanks, I've been using the plug for the current system (Magnetek power center that was originally installed in 2000 and a lead-acid battery), but I'm not sure what the current draw was on that battery. I'll look into the Anderson plug you mention.

 

[HRTKD]

Bob's point is important depending on a couple of factors. 1. Do you expect to need to charge the battery from the truck's alternator. 2. How much current the truck is capable of providing at the 7 pin.

My 2017 F-350 won't ever provide more than 30 amps of current at the 7 pin. Real world numbers show that it's more like 20 amps, on a good day. If I didn't have enough solar then getting more juice out of the truck would be appropriate. As it is, the current from the 7 pin is considered a maintenance charge rather than bring the batteries back to 100% charge.

I looked at the Victron line of chargers (like the IP22) and there was something about it that just didn't fit in with my system. I can't remember what it was though. I went with the DLS-55 from IOTA Engineering instead. But I have 5 times the Ah battery capacity than you do. I ran 6 awg between the converter and the bus bar. If your converter can't provide as many amps then 8 awg may be sufficient.

Logistics: You may find that using all 6 awg is easier. Fewer lugs to buy and less scrap wire at the end. The largest gauge that my Victron manual said my Victron 100/50 could handle was 6 awg, so I went with that.

What are you using to monitor your battery state of charge? Since you already have a lot of blue products, consider the Victron BMV-712.

 

[Bob B]

Bob's point is important depending on a couple of factors. 1. Do you expect to need to charge the battery from the truck's alternator. 2. How much current the truck is capable of providing at the 7 pin.

My 2017 F-350 won't ever provide more than 30 amps of current at the 7 pin. Real world numbers show that it's more like 20 amps, on a good day. If I didn't have enough solar then getting more juice out of the truck would be appropriate. As it is, the current from the 7 pin is considered a maintenance charge rather than bring the batteries back to 100% charge.

I looked at the Victron line of chargers (like the IP22) and there was something about it that just didn't fit in with my system. I can't remember what it was though. I went with the DLS-55 from IOTA Engineering instead. But I have 5 times the Ah battery capacity than you do. I ran 6 awg between the converter and the bus bar. If your converter can't provide as many amps then 8 awg may be sufficient.

Logistics: You may find that using all 6 awg is easier. Fewer lugs to buy and less scrap wire at the end. The largest gauge that my Victron manual said my Victron 100/50 could handle was 6 awg, so I went with that.

What are you using to monitor your battery state of charge? Since you already have a lot of blue products, consider the Victron BMV-712.

The Lance plug is not the standard 7 pin plug .... It is a 6 pin plug and the power leads and connections are beefier than the rest of the cable. It will carry more power than the 7 pin, but I don't know the specs.

 

[AZLance]

The Lance plug is not the standard 7 pin plug .... It is a 6 pin plug and the power leads and connections are beefier than the rest of the cable. It will carry more power than the 7 pin, but I don't know the specs.

Bob's point is important depending on a couple of factors. 1. Do you expect to need to charge the battery from the truck's alternator. 2. How much current the truck is capable of providing at the 7 pin.

My 2017 F-350 won't ever provide more than 30 amps of current at the 7 pin. Real world numbers show that it's more like 20 amps, on a good day. If I didn't have enough solar then getting more juice out of the truck would be appropriate. As it is, the current from the 7 pin is considered a maintenance charge rather than bring the batteries back to 100% charge.

I looked at the Victron line of chargers (like the IP22) and there was something about it that just didn't fit in with my system. I can't remember what it was though. I went with the DLS-55 from IOTA Engineering instead. But I have 5 times the Ah battery capacity than you do. I ran 6 awg between the converter and the bus bar. If your converter can't provide as many amps then 8 awg may be sufficient.

Logistics: You may find that using all 6 awg is easier. Fewer lugs to buy and less scrap wire at the end. The largest gauge that my Victron manual said my Victron 100/50 could handle was 6 awg, so I went with that.

What are you using to monitor your battery state of charge? Since you already have a lot of blue products, consider the Victron BMV-712.

Thanks Jim,

I don't expect to charge the battery from the truck too much, I expect to either charge from shore power while parked at home, or from the solar (lots of sunshine in AZ). I never measured how much current I'm getting through the 7-pin. I have a Ram 2500 diesel, and I found some charts for the amperage that the alternator produces that go into hundreds of amps, but that is at the alternator, don't know how much is passed through the 7-pin. I found in Orion manual it doesn't have the option to report amps either, but given that they update the firmware for their products constantly I hope this will be available in the future. And to answer Bob's comment, my Lance does have a 7-pin connector (It's a 2000 Lance Lite 835), though I bought it used so I don't know if it's original or if someone had replaced the 6-pin with a 7-pin.

I decided to go with IP22 because I like the idea of all components talking to each other on the same network, mostly because I hope that if there is an issue I'll get notified That was the only small charger that had connections for the cables, unlike for example IP65 or IP67 series which have the thin wires that go directly on the battery (if that makes sense?).

As for the wires, I basically looked at all the technical sheets for MPPT, Orion-TR, IP22 and Phoenix inverter and noted the maximum cable size (10, 6, 6 and 8), and went with that. The converter is relatively low wattage compared to what I'm seeing on forums and on Will's youtube videos (375W, peak 700W), and given that the max gauge listed is 8 I hope it's going to be sufficient.

Thanks for the suggestion, I am ordering the BMV-712 as well!
-Darko

 

[Bob B]

I bought my 1181 used and the previous owner had also replaced the Lance plug with the standard 7 pin.

 

[AZLance]

A follow up question: I started assembling the whole system, and updated the schematics, because I realized I didn't include DC loads that are going to be connected in the camper: I realized one thing: If I connect the Orion TR DC to DC to my truck 7-pin plug while my camper DC is also connected to the truck 7-pin then the input and output voltage will be set by Orion, I think? I think I need to break direct connection between the truck 7-pin and the camper fuse box, so that the input voltage to Orion is whatever the truck is putting out, and that the output voltage to the battery and the camper DC distribution is set by the Orion/battery. I highlighted the problematic connection in the updated schematics. Is my assumption correct?
Also, should I separate the positive busbars between the charging devices (Smart Solar, Orion, IP22) and the devices that use DC (Camper loads and Phoenix inverter)? I saw that Victron in their schematics has a switch to turn off loads, e.g. https://www.victronenergy.com/uploa...charger-12-50-1-inverter-375W-MPPT-100-30.pdf.
I've uploaded the updated schematics.