Truck Camper Build

[neil_99]

I've attached a PDF with my design for a 12V power system for a Host Mammoth I've ordered. Most of the equipment will go at the front of the basement which is what is drawn at the top of my design. I won't have the camper until next year. But my plan is to have the batteries built and the electrical system ready to install when it comes in. I've already ordered the Eve cells and BMS units from Amy. Everything else shown on the PDF hasn't been purchased yet. I'd really appreciate opinions and suggestions about my design. I've done a preliminary energy audit and I came up with around 3800 Watt-hours per day, but that's definitely on the high side of what I think I will actually use. The BMS units shown are the JBD 100A 12v units. Thanks!

 

[Zwy]

I've attached a PDF with my design for a 12V power system for a Host Mammoth I've ordered. Most of the equipment will go at the front of the basement which is what is drawn at the top of my design. I won't have the camper until next year. But my plan is to have the batteries built and the electrical system ready to install when it comes in. I've already ordered the Eve cells and BMS units from Amy. Everything else shown on the PDF hasn't been purchased yet. I'd really appreciate opinions and suggestions about my design. I've done a preliminary energy audit and I came up with around 3800 Watt-hours per day, but that's definitely on the high side of what I think I will actually use. The BMS units shown are the JBD 100A 12v units. Thanks!

Why a 12v system with a 3000w inverter?

I built mine with a 24v system, 3000w inverter and with a buck converter for 12v circuits. With just the buck converter on with no load, the draw is 0.003 amps, not enough to be concerned about.

To each their own but I would seriously consider a 24v system just due to voltage drop on the heavily loaded circuits, never mind the smaller gauge wire that can be used.

I just returned from a week long trip with my 24v truck camper and spent most of the time without shore power, in fact only 2 nights hooked to shore power just because it was there. Everything worked great. I run a Dometic CFX95 fridge/freezer in the truck cab rear seating area off the solar plus the furnace every night. Barely used 10% of my battery power in a night.

Right now I'm thinking of swapping out the 3 way fridge, which we didn't use and installing a 24v compressor fridge.

 

[rmaddy]

FYI - A wiring schematic would be much easier for people to review your planned electrical system.

 

[neil_99]

Why a 12v system with a 3000w inverter?

I built mine with a 24v system, 3000w inverter and with a buck converter for 12v circuits. With just the buck converter on with no load, the draw is 0.003 amps, not enough to be concerned about.

To each their own but I would seriously consider a 24v system just due to voltage drop on the heavily loaded circuits, never mind the smaller gauge wire that can be used.

I just returned from a week long trip with my 24v truck camper and spent most of the time without shore power, in fact only 2 nights hooked to shore power just because it was there. Everything worked great. I run a Dometic CFX95 fridge/freezer in the truck cab rear seating area off the solar plus the furnace every night. Barely used 10% of my battery power in a night.

Right now I'm thinking of swapping out the 3 way fridge, which we didn't use and installing a 24v compressor fridge.

I've gone back and forth a bunch of times on 12V vs 24V. The reason I'm going with 12V is that I would like to have the ability to do DC-DC charging. I don't want to carry a generator, so the DC-DC charging gives me a backup way of charging if the sun isn't out for several days. I know I could get a Sterling Power 12/24 DC-DC charger, and then step back down, but that seems more complicated, and is basically the same cost (bigger wires vs more expensive equipment).

 

[neil_99]

FYI - A wiring schematic would be much easier for people to review your planned electrical system.

I'll work on that and try to post something like a flowchart with the wiring.

 

[HRTKD]

Why a 12v system with a 3000w inverter?

Because the Victron 12/3000 inverter/charger is really only a 2400 watt inverter. It being closer to 2000 watts than 3000 watts makes it a good fit for 12v. If @neil_99 really needs 3000 watts then a larger inverter and a battery bank with different voltage would be in order.

 

[HRTKD]

I've gone back and forth a bunch of times on 12V vs 24V. The reason I'm going with 12V is that I would like to have the ability to do DC-DC charging. I don't want to carry a generator, so the DC-DC charging gives me a backup way of charging if the sun isn't out for several days. I know I could get a Sterling Power 12/24 DC-DC charger, and then step back down, but that seems more complicated, and is basically the same cost (bigger wires vs more expensive equipment).

I like where you're headed with this. It looks like you're planning on 800 watts of PV. Is that mounted on the roof or deployed on the ground? I would urge you to reconsider the Renogy DC-DC device. If you have Victron for everything else, a Victron DC-DC that can be monitored by the Cerbo GX will be nice. Plus, there have been a lot of problems with Renogy lately. Poor quality and even worse customer service.

Your drawing shows the JBD 100amp BMS. Most of us are using the 120 amp BMS, either from JBD or Overkill Solar (where mine came from).

A beautiful, meticulous drawing doesn't always translate to an easy wiring install. Make sure you leave plenty of room for wires and for wires to bend. My install looked great, right up until I started adding the cables.

 

[neil_99]

Because the Victron 12/3000 inverter/charger is really only a 2400 watt inverter. It being closer to 2000 watts than 3000 watts makes it a good fit for 12v. If @neil_99 really needs 3000 watts then a larger inverter and a battery bank with different voltage would be in order.

That does lead to a question. Will the Victron carry both the AC and the microwave at the same time for short periods? My AC has a max wattage of 1550watts. My microwave is 1000W for the microwave part (it's a microwave convection oven, but I don't think I would use the AC and the oven part at the same time). Those two added together are more than 2400W. I'm confused by the paperwork for the Multiplus. Will it really not carry 3000W? How is it a 3000W inverter but only 2400VA aren't those basically the same thing?

 

[neil_99]

I like where you're headed with this. It looks like you're planning on 800 watts of PV. Is that mounted on the roof or deployed on the ground? I would urge you to reconsider the Renogy DC-DC device. If you have Victron for everything else, a Victron DC-DC that can be monitored by the Cerbo GX will be nice. Plus, there have been a lot of problems with Renogy lately. Poor quality and even worse customer service.

Your drawing shows the JBD 100amp BMS. Most of us are using the 120 amp BMS, either from JBD or Overkill Solar (where mine came from).

A beautiful, meticulous drawing doesn't always translate to an easy wiring install. Make sure you leave plenty of room for wires and for wires to bend. My install looked great, right up until I started adding the cables.

I've wondered the same thing. The JBD that Amy is selling is listed as 100amps. It looks the same, but appears to have smaller/fewer wires solderd to the board. I'm not sure if there are any other differences.

 

[MattiFin]

That does lead to a question. Will the Victron carry both the AC and the microwave at the same time for short periods? My AC has a max wattage of 1550watts. My microwave is 1000W for the microwave part (it's a microwave convection oven, but I don't think I would use the AC and the oven part at the same time). Those two added together are more than 2400W. I'm confused by the paperwork for the Multiplus. Will it really not carry 3000W? How is it a 3000W inverter but only 2400VA aren't those basically the same thing?

You got the numbers mixed up: 3000VA and 2400W
VA and W are same only for resistive ”perfect” load

AC power - Wikipedia

en.wikipedia.org

 

[neil_99]

FYI - A wiring schematic would be much easier for people to review your planned electrical system.

I've attached a wiring diagram. Please let me know if I could show it in a more helpful way. Thanks.

 

[neil_99]

You got the numbers mixed up: 3000VA and 2400W
VA and W are same only for resistive ”perfect” load

AC power - Wikipedia

en.wikipedia.org

So, when I compare a Victron 3000VA inverter to another brand 3000W inverter are they really different? Or is Victron just being overly cautious? How far from a resistive perfect load is normal RV usage?

 

[neil_99]

Okay, so I read an article again and I think I better understand. So it really only has 3000W in instances where the load is something simple like a heat coil. When a motor gets involved it drops, so almost all uses will be limited to 2400W. Am I understanding correctly now? Also, are other inverters like the Gopower or Giandel 3000W inverters the same and they just don't go into this detail, or do other inverters actually have more capacity?

 

[HRTKD]

I've wondered the same thing. The JBD that Amy is selling is listed as 100amps. It looks the same, but appears to have smaller/fewer wires solderd to the board. I'm not sure if there are any other differences.

100 amps x 4 or 120 amps x 4 is still a lot of amps and more than you'll pull even from an inverter that says it can deliver 3000 watts. As long as it supports bluetooth for making configuration changes and monitoring, that's good enough.

 

[rmaddy]

I've attached a wiring diagram. Please let me know if I could show it in a more helpful way. Thanks.

Some observations on your wiring diagram (all my comments about wire and fuse sizes is based on Blue Sea Systems recommendations which assume you are using high quality copper stranded wire with 105ºC rated insulation).

- You should connect all of your batteries to bus bars. Then the fuse can connect to the positive bus bar and the shunt can connect to the negative bus bar.
- You propose 1/0 cables with 400A fuses between the batteries and inverter. Given that the inverter is 12V/3000W you probably do end up wanting 400A fuses but 1/0 cables is much too small. The max fuse for 1/0 is 300A. You should use 4/0 wire to support the inverter. That also makes it safe to use 400A fuses.
- The 2AWG wire between the SCC and Lynx is probably overkill. For the 85A load 4AWG should be enough. And the 120A fuse could be close to 105A. But 120A does work, even with 4AWG.
- I don't know the specs of your solar panels so hopefully you've verified that they won't be over 25A given the choice of 32A breaker.
- You might want an AC breaker between the 30A shore power plug and the inverter's AC-in. I did this on mine to help protect my system from a bad AC source.
- You should consider a breaker/disconnect between the SCC and the Lynx instead of the fuse. This would make it easier to turn off the SCC should you have a need to work on the solar while keeping the rest of your system active.
- Given your Victron components you may want to consider having a GX and display (or a Raspberry Pi running VenusOS). I have a Raspberry Pi and display for my setup and it is immensely useful. If you go that route you may be better off getting a BMV-712 instead of the smart shunt. But verify whether the smart shunt can easily connect to the GX or RPi.

 

[John Frum]

So it really only has 3000W in instances where the load is something simple like a heat coil. When a motor gets involved it drops, so almost all uses will be limited to 2400W. Am I understanding correctly now? Also, are other inverters like the Gopower or Giandel 3000W inverters the same and they just don't go into this detail, or do other inverters actually have more capacity?

Giandel makes high frequency inverters
Gopower has high frequency and low frequency inverters so it depends on the model.
Victron inverter/chargers are low frequency and high quality.

High frequency inverters typically have a 2x surge rating for ~20ms.
This surge capacity is only important to the relevant marketing departments.

Low frequency inverters typically have a 2x surge rating in seconds or minutes.

Lots of people buy Giandel for their first inverter.
I doubt many buy Giandel for their second inverter.

 

[neil_99]

Some observations on your wiring diagram (all my comments about wire and fuse sizes is based on Blue Sea Systems recommendations which assume you are using high quality copper stranded wire with 105ºC rated insulation).

- You should connect all of your batteries to bus bars. Then the fuse can connect to the positive bus bar and the shunt can connect to the negative bus bar.
- You propose 1/0 cables with 400A fuses between the batteries and inverter. Given that the inverter is 12V/3000W you probably do end up wanting 400A fuses but 1/0 cables is much too small. The max fuse for 1/0 is 300A. You should use 4/0 wire to support the inverter. That also makes it safe to use 400A fuses.
- The 2AWG wire between the SCC and Lynx is probably overkill. For the 85A load 4AWG should be enough. And the 120A fuse could be close to 105A. But 120A does work, even with 4AWG.
- I don't know the specs of your solar panels so hopefully you've verified that they won't be over 25A given the choice of 32A breaker.
- You might want an AC breaker between the 30A shore power plug and the inverter's AC-in. I did this on mine to help protect my system from a bad AC source.
- You should consider a breaker/disconnect between the SCC and the Lynx instead of the fuse. This would make it easier to turn off the SCC should you have a need to work on the solar while keeping the rest of your system active.
- Given your Victron components you may want to consider having a GX and display (or a Raspberry Pi running VenusOS). I have a Raspberry Pi and display for my setup and it is immensely useful. If you go that route you may be better off getting a BMV-712 instead of the smart shunt. But verify whether the smart shunt can easily connect to the GX or RPi.

• I guess you are right that I'll probably have trouble connecting 4 wires to the shunt and fuse. I'll add the bus bars.
• I was planning on using 1/0 from each battery since no single battery will carry more than 100amps. The wires coming from the negative side of the BMS are tiny compared to 1/0. After the fuse and shunt I'm running 4/0 to the Lynx (I now notice that I do have 1/0 between the fuse and the disconnect switch, I'll switch it to 4/0). The Multiplus manual calls for double 1/0, which has around the same crossectional area as 4/0. I've seen videos online of people complaining that 4/0 doesn't fit into the Multiplus without modification. That's why I'm running double 1/0.
• I'll double check these numbers. 2AWG does seem like overkill.
• Yeah, I believe I'm right around 23A max.
• That's a great suggestion. In fact, I may want something that would allow me to run the external AC directly to the house if something does wrong with my inverter.
• I figured I already had this by having the breaker before the SCC. I would shut off the SCC by cutting off the panels at the breaker. I guess what you are saying is the other side is still hot, which could be a problem. The fuse will stay since it is actually going to be on the Lynx.
• I'm planning on having a Cerbo GX, but not the screen. I've wondered how much benefit the display will give vs. just using my phone as a screen. It sounds like you have found it to be valuable. Can you tell me what you get with your Pi screen that you don't get with your phone?

 

[neil_99]

Giandel makes high frequency inverters
Gopower has high frequency and low frequency inverters so it depends on the model.
Victron inverter/chargers are low frequency and high quality.

High frequency inverters typically have a 2x surge rating for ~20ms.
This surge capacity is only important to the relevant marketing departments.

Low frequency inverters typically have a 2x surge rating in seconds or minutes.

Lots of people buy Giandel for their first inverter.
I doubt many buy Giandel for their second inverter.

It sounds like I'll be better off with a Victron rated for 3000VA than one of those others rated for 3000W. Thanks!

 

[memilanuk]

a Victron DC-DC that can be monitored by the Cerbo GX will be nice.

I was under the impression that the Orion chargers were the oddball in that they don't talk to a Cerbo like the solar charge controllers and inverter charger ?

 

[John Frum]

It sounds like I'll be better off with a Victron rated for 3000VA than one of those others rated for 3000W. Thanks!

1. Consider the Victron to be rated at 2400 watts which assumes an overall power factor of 0.8.
2. Its an inverter/charger with built in automatic transfer switch which is a whole ofther thing compared to a discrete inverter like the Giandel.
3. As mentioned about its a low frequency inverter. Discrete low frequency inverters are as rare as unicorns. I'm not sure anyone makes one these days.

IMO the most directly comparable inverter/charger to the Victron would be this one https://www.donrowe.com/samlex-evo-2212-pure-sine-inverter-charger-p/evo-2212.htm