Truck Camper - 12v vs 48v?

[cgi2099]

Hey all, was trying to get some advice on 12v vs 48v for our truck camper.

Would it be better to go with a 48v system with inverter to 120v for the appliances and install a 48v alternator on the Powerstroke?

Or better to stay 12v and run 12v appliances with no inverter?

We are after run time. Plan is to run either x2 48v 100ah EG4 or x2 400ah 12v EG4 and what ever charger, inverter needed for either system.

I am told that the 12v system with what we are planning to run would be able to run us for a couple days with shore power. I have no idea on the 48v stuff. The thought on the 48v stuff was to save money on the conductors and a lower overall amp system.

 

[cgi2099]

With zero experience, I would think the systems would look like this:

48v system:
EasySolar-II 48/3000/35-32 MPPT 250/70 GX
x2 24v poly panels 300w
x2 - 100ah 48v EG4
EG4 Chargeverter
48v Truck Alternator


12v system:
SmartSolar MPPT 150/45
Phoenix 12/50
Orion-Tr-Smart 12/12-30
x2 24v poly panels 300w
x2 - 400ah 12v EG4
Maybe small 120 inverter (shouldn't need it though)

 

[Zwy]

I run 24V on my truck camper. This gives me a 3000 watt inverter and over 6000 watt hours of power. Wire size is smaller, much easier to run in tight places. I have run the roof air off battery power and it handled it fine but I'm installing a mini split to increase run time.

The 12V appliances and lights are still in place. I run a 24V to 12V converter and the converter is never shut off, the idle draw is basically nothing.

48V on a truck camper is serious overkill.

As for charging off the truck alternator, I installed a second 12V 250A alternator, a 2600W inverter in the back seat and have a 30A RV receptacle at the rear bumper so I can plug in the all in one inverter and use it's AC charger. I installed all of that but never really use it. It can also provide backup power if I needed it for redundancy.

You can read about my truck camper system by clicking the blue link in my signature at the bottom of this post.

 

[littleharbor2]

What would be the minimum MPPT startup voltage of the 48 volt AIO? What is the Vmp. of the 300 watt panels? You need to make sure you can exceed the minimum voltage with flat hot panels. Might be difficult. Do you have room fora 3rd panel? in your case you might be better with a 12 volt system. You also wouldn't need a 48 to 12 volt stepdown unit with a 12 volt system.

 

[cgi2099]

Thank you so much for the responses : )

Is there a huge loss say going from 24v to 120v to run appliances with an inverter vs running 24v (or 12v) appliances?

How much run time would I be losing if any, for:

x2 48v 100 ah
x2 24v 200 ah
x2 12v 400 ah

 

[cgi2099]

What would be the minimum MPPT startup voltage of the 48 volt AIO? What is the Vmp. of the 300 watt panels? You need to make sure you can exceed the minimum voltage with flat hot panels. Might be difficult. Do you have room fora 3rd panel? in your case you might be better with a 12 volt system. You also wouldn't need a 48 to 12 volt stepdown unit with a 12 volt system.

I was worried about this, 48v probably isn't feasible then, 2 panels is pretty much all I have room for, I could fit a half panel maybe but it'd be tight

 

[littleharbor2]

Many low voltage dc appliances are either cheaply built, or quite expensive for quality. Your losses IMHO will be in the efficiency of the inverter.

All 3 batteries contain the same amount of power.

 

[cgi2099]

delete

 

[littleharbor2]

I was worried about this, 48v probably isn't feasible then, 2 panels is pretty much all I have room for, I could fit a half panel maybe but it'd be tight

If you go 48 volt then be sure you choose higher voltage panels, and they work with the minimum voltage requirements of the inverter.

 

[littleharbor2]

So the goal for us is to be able to take a 3-4 day trip and be able to run the ac unit and everything else without issue and no shore power. We originally were looking at those roof top 12-24v ac units which are suppose to be really efficient.

I just don't know if it would be better to do that or to get a small 120v mini split and just run all 120v appliances?

Pretty much just be running the a/c, refrigerator, tankless water heater, some led lights and charge our phones.

Have you already purchased the tankless W/H? If not, go propane. I had a small one in my camper and loved it.

 

[cgi2099]

Many low voltage dc appliances are either cheaply built, or quite expensive for quality. Your losses IMHO will be in the efficiency of the inverter.

All 3 batteries contain the same amount of power.

I run 24V on my truck camper. This gives me a 3000 watt inverter and over 6000 watt hours of power. Wire size is smaller, much easier to run in tight places. I have run the roof air off battery power and it handled it fine but I'm installing a mini split to increase run time.

The 12V appliances and lights are still in place. I run a 24V to 12V converter and the converter is never shut off, the idle draw is basically nothing.

48V on a truck camper is serious overkill.

As for charging off the truck alternator, I installed a second 12V 250A alternator, a 2600W inverter in the back seat and have a 30A RV receptacle at the rear bumper so I can plug in the all in one inverter and use it's AC charger. I installed all of that but never really use it. It can also provide backup power if I needed it for redundancy.

You can read about my truck camper system by clicking the blue link in my signature at the bottom of this post.

So the goal for us is to be able to take a 3-4 day trip and be able to run the ac unit and everything else without issue and no shore power. We originally were looking at those roof top 12-24v ac units which are suppose to be really efficient.

I just don't know if it would be better to do that or to get a small 120v mini split and just run all 120v appliances?

Pretty much just be running the a/c, refrigerator, tankless water heater, some led lights and charge our phones.

 

[cgi2099]

Have you already purchased the tankless W/H? If not, go propane. I had a small one in my camper and loved it.

I'm hoping we can do propane but space is limited is why I was thinking electric. I'll start looking into the propane ones : )

 

[littleharbor2]

I'm hoping we can do propane but space is limited is why I was thinking electric. I'll start looking into the propane ones : )

For starters, you're asking a lot from your battery wanting to run AC. Sure you can run it for a while on your proposed battery bank but the problem is, How long it'll take to replace that used power? With 6-700 watts of poorly aligned PV you will struggle to replace it, especially when you are needing to charge your battery AND run the AC. That's not possible without a much larger solar array. That size array will maybe be sufficient to run your refer and the other small loads. I wouldn't expect it to run any more than that. Keep in mind, you will need to park in the sun to get any meaningful power from your panels. Your camper will get warm in the sun. Maybe consider adding a couple free standing panels to the mix.

 

[Johneb]

I too went with a 24v system in our host cascade. Samlex EVO 2224 inverter/charger. DIY 300ah 24v battery. Victron 24v to 12v adapter. If I was to do it again I would just keep my 12v system intact and add the EVO for 120v only.

 

[Zwy]

So the goal for us is to be able to take a 3-4 day trip and be able to run the ac unit and everything else without issue and no shore power. We originally were looking at those roof top 12-24v ac units which are suppose to be really efficient.

The COP on the 12-24V ac units is not that good. That is still a work in progress with more advances coming. I would not be in a hurry to purchase one.

It will take a good sized battery bank to run AC all the time.

I just don't know if it would be better to do that or to get a small 120v mini split and just run all 120v appliances?

You should have water pump, lights, fans, range fan and many other things that are 12V. Leave those in place, just use a 24V to 12V converter to power that fuse panel. Even using a DC fridge instead of a small inverter with a 120V AC fridge is more efficient.

The problems with an RV such as a truck camper is limited roof real estate combined with limited battery capacity due to space and weight requirements. Those 2 factors will require not having an inverter turned on when 120V power isn't needed. Inverter idle consumption with limited PV and battery is a waste of resources and lead to not having AC power when you want it.

Loads that run often, use DC power. Loads that require 120V AC power, use an inverter you can easily switch on/off. We have a switch mounted in the galley, easily reached and switched. Only run the inverter when you need AC power.

There will always be efficiency losses using any inverter. Figure 10% due to idle consumption and conversion losses. So a 280Ah battery becomes 28Ah's less watts available to use.

Pretty much just be running the a/c, refrigerator, tankless water heater, some led lights and charge our phones.

AC= sparingly
Fridge- DC powered, 12/24V
water heater- propane
LED lights- DC powered
Charge phones- use a 12V adapter

 

[Zwy]

I too went with a 24v system in our host cascade. Samlex EVO 2224 inverter/charger. DIY 300ah 24v battery. Victron 24v to 12v adapter. If I was to do it again I would just keep my 12v system intact and add the EVO for 120v only.

I wouldn't go back to a 12V system on my truck camper. I want to run AC loads that draw plenty of power and the 24V system handles it so well.

Microwave & AC are the biggest loads along with the wife using the blow dryer and curling iron.

12V system I would probably hear, "Honey, the system keeps shutting down when I dry my hair".

 

[time2roll]

My RV trailer has a 12v battery and 2000w inverter that has no issues with anything including extended use of a hairdryer or microwave. Can run the 13.5 Dometic A/C without issue.

No way would I want to complicate everything running dual voltage unless I needed 3500+ watts inverter or 1500+ watts solar. That would be a massive system for a TC.

 

[Johneb]

I wouldn't go back to a 12V system on my truck camper. I want to run AC loads that draw plenty of power and the 24V system handles it so well.

Microwave & AC are the biggest loads along with the wife using the blow dryer and curling iron.

12V system I would probably hear, "Honey, the system keeps shutting down when I dry my hair".

My 12v system ran only 12v stuff. The 120v stuff i.e. hair dryer, curling iron was run by the EVO. As soon as you unplugged from shore power the EVO took over fast enough if you were watching tv, curling your hair you wouldn't know you lost shore power.

 

[Dooug]

Do you have electric camper jacks? If so it is not easy to find a 48/12 to run them. 30 amps is not quite enough to run the jacks. its not hard to find a 24/12 volts 70 amp or 45 amp unit to run the jack. I purchased a 70 amp converter to run my jacks and a seperate 25 amp to run the furnace and lights.

 

[HighDesertOffgrid]

My RV trailer has a 12v battery and 2000w inverter that has no issues with anything including extended use of a hairdryer or microwave. Can run the 13.5 Dometic A/C without issue.

No way would I want to complicate everything running dual voltage unless I needed 3500+ watts inverter or 1500+ watts solar. That would be a massive system for a TC.

I fall in this camp as well. I don't see much benefit from other than 12v.