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12v or 24v battery

I finally found the idle draw of the Growatt you’re considering: 50W.

Not 115W like someone else found, but 50W is still what I consider very high for a mobile situation.

I simply mounted a on/off switch in the galley of my truck camper to turn off the inverter remotely. The AIO charge controller will charge the batteries with the inverter off.

In a camper, most items will be be the system voltage, 12V or 24V. Inverters are only needed to run the 120V items, such as microwave, TV, air conditioning or recharge a laptop if you don't have a mobile charger. The 2 biggest 120V items used in our camper is the microwave and my wife's blow dryer. (Yes, she has to wash her hair and blow dry it daily in the middle of a National Forest).

Idle draw is not a huge concern of mine, it doesn't idle because when I turn it on, I'm using it.
 
In a camper, most items will be be the system voltage, 12V or 24V. Inverters are only needed to run the 120V items, such as microwave, TV, air conditioning or recharge a laptop if you don't have a mobile charger.

You missed one here that many campers go for: AC fridge. Since it needs power 24/7, turning off the inverter isn’t an option. Then the convenience of an AIO doesn’t seem so nice due to higher idle draw. This is where the low idle draw of the Victron devices really shines.
 
You missed one here that many campers go for: AC fridge. Since it needs power 24/7, turning off the inverter isn’t an option. Then the convenience of an AIO doesn’t seem so nice due to higher idle draw. This is where the low idle draw of the Victron devices really shines.
Get a AC/DC fridge. I run my Dometic CFX95 that sits in back seat area of my truck cab off the 24V solar system in the truck camper. Takes about 35W when running. As for the 3 way in the truck camper, we haven't been using it. I will remove it at some point and install a 24V compressor fridge. Right now, the next phase is finishing removing the roof AC unit and installing the mini split.

Someone with a big 5th wheel or coach might opt for a AC household fridge. But that would allow more PV and larger 48V battery bank. The idle draw would not matter with a larger system.
 
Get a AC/DC fridge. I run my Dometic CFX95 that sits in back seat area of my truck cab off the 24V solar system in the truck camper. Takes about 35W when running. As for the 3 way in the truck camper, we haven't been using it. I will remove it at some point and install a 24V compressor fridge. Right now, the next phase is finishing removing the roof AC unit and installing the mini split.

Someone with a big 5th wheel or coach might opt for a AC household fridge. But that would allow more PV and larger 48V battery bank. The idle draw would not matter with a larger system.
The problem is you're sacrificing convience. When designing systems convince should be priority if not the most important. I also doubt they're nearly as efficient. My huge 19cu ft fridge has an average consumption of 360kw per year that's under 1kw per day. My total idle consumption is about 100w for AC.
 
The problem is you're sacrificing convience. When designing systems convince should be priority if not the most important. I also doubt they're nearly as efficient. My huge 19cu ft fridge has an average consumption of 360kw per year that's under 1kw per day. My total idle consumption is about 100w for AC.
It's one thing in a coach, quite another in a situation like the OP.

Some of us go off the highway. You choose to be tied to highways with the coach, we choose to be rugged and in the sticks.

BTW, if I used my Dometic for 365 days, the consumption would be around 165Kwh, less than half your 19 cu foot fridge.
 
It's one thing in a coach, quite another in a situation like the OP.

Some of us go off the highway. You choose to be tied to highways with the coach, we choose to be rugged and in the sticks.

BTW, if I used my Dometic for 365 days, the consumption would be around 165Kwh, less than half your 19 cu foot fridge.
Sure but you're 3cuft vs my 19. 50% power but only 15% capacity. Also that's my energy star rating which means it's based on usage for a family using all the time in a home opening/closing multiple times a day. I haven't seen any 12V fridges that are decent sized and the cooler type is just hard to store food for meals. I cook a lot and even the 19cuft barely keeps enough drinks and food for a weekend.

Wish my rig was more offroad capable but were stuck at the trailheads and using the SxSs. Still working on what works best for us and hopefully getting out west this fall to see what we like.
 
Get a AC/DC fridge.
We had one and got rid of it. It pulled 500w continuous on AC power and I don’t recall the DC pull, but it was not very efficient either. Our 7.5cf AC fridge runs on 600W for 5 seconds, then 40-60w after that.
 
Sure but you're 3cuft vs my 19. 50% power but only 15% capacity. Also that's my energy star rating which means it's based on usage for a family using all the time in a home opening/closing multiple times a day. I haven't seen any 12V fridges that are decent sized and the cooler type is just hard to store food for meals. I cook a lot and even the 19cuft barely keeps enough drinks and food for a weekend.

There is just the wife and I, if had family I would need a bigger rig.

The CFX95 is actually too big for the van build I started. Now that I have the truck camper and use the CFX95 in it, I can get a smaller unit for the van build. The van is for short stays fishing for a few days.

Wish my rig was more offroad capable but were stuck at the trailheads and using the SxSs. Still working on what works best for us and hopefully getting out west this fall to see what we like.
If you have any more than 2 people, it starts getting cramped if you want off road capability. I've had some interesting trips. Here was one. https://diysolarforum.com/threads/server-rack-batteries-in-an-rv.33249/post-410586

I had a pop up truck camper before, have climbed up muddy mountains west of Yellowstone. I wouldn't want anything bigger than what I have now. It is pretty capable. I can set up base camp far away from the crowds.
 
We had one and got rid of it. It pulled 500w continuous on AC power and I don’t recall the DC pull, but it was not very efficient either. Our 7.5cf AC fridge runs on 600W for 5 seconds, then 40-60w after that.
Some AC/DC brands do, no doubt about that. Even with the Dometic in the truck cab sitting in the hot sun with no windows open, (of course 600W of solar is powering it) it doesn't draw my battery down.

I'm waiting on the DC fridge swap as we 1, don't need it right away and 2, I'd like to see some efficiency gains on the units I looked at that fit the opening. I'm patient.
 
Any help choosing a 400ah 12v system or 200ah 24v system would be appreciated!
Look at my avatar. All DIY.

I am running a 5120Wh, 200Ah 24V AIO system with a 3000W Growatt AIO, in the van with 981W solar on the van roof. I have a 30A RV socket in the rear where I plug in my 30A trailer. I set this up so I could travel freely and enjoy A/C overnight. It works splendidly. I do carry a Yahama 2000is genny as backup. I run all the 110V devices in the trailer, including a 110V counter high upright freezer which is controlled externally by a BIRD thermometer. The BIRD is set to regular fridge temps around 40F. It runs 10min/hr. Love that extra insulation!

The 24V in the van runs a 12/24 dcV portable fridge/freezer set to 5F. It is my freezer. I do also run a raspberry pi at 5V through a $2, 0-40V to 5V adapter. I have no 12V loads in the van.

Comments?
 
Look at my avatar. All DIY.

I am running a 5120Wh, 200Ah 24V AIO system with a 3000W Growatt AIO, in the van with 981W solar on the van roof. I have a 30A RV socket in the rear where I plug in my 30A trailer. I set this up so I could travel freely and enjoy A/C overnight. It works splendidly. I do carry a Yahama 2000is genny as backup. I run all the 110V devices in the trailer, including a 110V counter high upright freezer which is controlled externally by a BIRD thermometer. The BIRD is set to regular fridge temps around 40F. It runs 10min/hr. Love that extra insulation!

The 24V in the van runs a 12/24 dcV portable fridge/freezer set to 5F. It is my freezer. I do also run a raspberry pi at 5V through a $2, 0-40V to 5V adapter. I have no 12V loads in the van.

Comments?
What's the PI used for?
Look at my avatar. All DIY.

I am running a 5120Wh, 200Ah 24V AIO system with a 3000W Growatt AIO, in the van with 981W solar on the van roof. I have a 30A RV socket in the rear where I plug in my 30A trailer. I set this up so I could travel freely and enjoy A/C overnight. It works splendidly. I do carry a Yahama 2000is genny as backup. I run all the 110V devices in the trailer, including a 110V counter high upright freezer which is controlled externally by a BIRD thermometer. The BIRD is set to regular fridge temps around 40F. It runs 10min/hr. Love that extra insulation!

The 24V in the van runs a 12/24 dcV portable fridge/freezer set to 5F. It is my freezer. I do also run a raspberry pi at 5V through a $2, 0-40V to 5V adapter. I have no 12V loads in the van.

Comments?
That's genius to have all power in the van then plugged into TT!
 
Hi,

I'm looking to build a system this week, but I'm torn between a 400ah 12v or 200ah 24v battery.
Do you have enough room for two of 'em? If so, consider two 24V batteries in series for 48V.

There's lots of 12 and 48 volt equipment available, as they're standards for automotive and telephony infrastructure respectyively. Also: EVs are switching to 48V for accessories in upcoming generations so expect stuff for that to become still more available. 24V not so much.

(Then again, the CFX 95 does 12 and 24 but not 48V. Win some, lose some.)

Higher voltages seem unlikely for the foreseeable future, as the electrical regulations switch between the simpler low voltage sort and the more draconian, "this is touch-it-and-die", sort at nominal 50V.

Losses and heating in wiring go with the square of the current, power with the product of current and voltage, and insulation is pretty much all 600V (or better) because anything thinner is too flimsy anyhow. So compared to 12V a given grade if wire will deliver 2x the power at 24V, 4x at 48V. If you're rewiring for higher current at lower voltage, for a given amount of power delivered, compared to 40V, you'd need 4X as much pricey copper at 24V, 16x at 12V, to acheive the same level of loss and heating.
 
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What's the PI used for?
The Pi is a long DIY story. Fortunately, I have a degree in CS and had a long career in business data processing. I can design and program. Basically it logs data from the AIO and lets me see graphs through a web interface. Don't even think about asking for a copy of it. I run the last test that did not crash.
That's genius to have all power in the van then plugged into TT!
Mostly necessity as the trailer does not have enough cargo rating to add the system.
 
A lot of inverters will post their idle power consumption, but what about operating power consumption? If an inverter is 50watts at idle, does that mean when operating, it's 50watts + whatever you have plugged in at the time? Or is there a formula to figure it out?

When not in use I'd like an inverter that I can turn off to avoid any idle draw. If I go with an all in one, I'd like to have an on/off switch like Zwy that controls the inverter separate from the solar or shore charger. Is that a standard feature for all of the AIO's or is that something you have to add yourself?

I really like the EG4 battery but wish it would work with a wider range of inverters. Any way to make it work with a cheaper inverter found on Amazon without an RS485? Requiring an RS485 connection seems to limit the options to the larger AIO's.

Another concern with the AIO's is the noise. I only saw info on noise for one, the SunGold Power 3,000watt and that has a noise level greater than or equal to 60db! Thats seems pretty loud and could be distracting during the day or disturb your sleep if close by. Are all the AIO's pretty loud when compared to a smaller inverter like the Giandel 24v 2000watt that is suggested on mobile-solarpower.com? Thanks for the info!
 
Another concern with the AIO's is the noise.
Can’t answer to your AIO question or the Giandel inverter noise, but the 2000W Renogy and 12/1200 Victron I’ve owned are very quiet. Silent unless you’re pulling heavy draw but even when the fan kicks on it’s not bad, but the Victron is considerably quieter.

Which leads to a major drawback for using an AIO in a van or RV situation- the noise. Separate charge controller, charger and inverter can obviously cool themselves much easier and quieter compared to an AIO. An AIO, being much more compact, relies heavily upon noisy fans to cool the components. In contrast, my Renogy 30A charge controller has no fan at all and so is totally silent in operation.
 
A lot of inverters will post their idle power consumption, but what about operating power consumption? If an inverter is 50watts at idle, does that mean when operating, it's 50watts + whatever you have plugged in at the time? Or is there a formula to figure it out?

When not in use I'd like an inverter that I can turn off to avoid any idle draw. If I go with an all in one, I'd like to have an on/off switch like Zwy that controls the inverter separate from the solar or shore charger. Is that a standard feature for all of the AIO's or is that something you have to add yourself?

You simply add one. I used a rocker switch, the kind with the LED so you know when it is on. Will did a video a long time ago about adding a remote switch. I simply went into the inverter and cut the wires to the switch, then added another wire for each terminal so the switch side has two wires and crimped it together. This way you can turn on the inverter from either switch.

Check out my truck camper build. https://diysolarforum.com/threads/heres-my-truck-camper-setup.29488/


I really like the EG4 battery but wish it would work with a wider range of inverters. Any way to make it work with a cheaper inverter found on Amazon without an RS485? Requiring an RS485 connection seems to limit the options to the larger AIO's.

The EG4 battery will work with any SCC, you don't need communication.

Another concern with the AIO's is the noise. I only saw info on noise for one, the SunGold Power 3,000watt and that has a noise level greater than or equal to 60db! Thats seems pretty loud and could be distracting during the day or disturb your sleep if close by. Are all the AIO's pretty loud when compared to a smaller inverter like the Giandel 24v 2000watt that is suggested on mobile-solarpower.com? Thanks for the info!
It is more noise than the Giandel 2400W I own. I mounted mine outside the camper. Works well, I don't hear it and can leave the door open or run air thru the fan and vent. If you turn the inverter off at night, you won't hear anything until the sun comes up.
 
A lot of inverters will post their idle power consumption, but what about operating power consumption? If an inverter is 50watts at idle, does that mean when operating, it's 50watts + whatever you have plugged in at the time? Or is there a formula to figure it out?

When not in use I'd like an inverter that I can turn off to avoid any idle draw. If I go with an all in one, I'd like to have an on/off switch like Zwy that controls the inverter separate from the solar or shore charger. Is that a standard feature for all of the AIO's or is that something you have to add yourself?

I really like the EG4 battery but wish it would work with a wider range of inverters. Any way to make it work with a cheaper inverter found on Amazon without an RS485? Requiring an RS485 connection seems to limit the options to the larger AIO's.

Another concern with the AIO's is the noise. I only saw info on noise for one, the SunGold Power 3,000watt and that has a noise level greater than or equal to 60db! Thats seems pretty loud and could be distracting during the day or disturb your sleep if close by. Are all the AIO's pretty loud when compared to a smaller inverter like the Giandel 24v 2000watt that is suggested on mobile-solarpower.com? Thanks for the info!
Yes they should have an efficiency percentage like 94% so if you're inverting 100w it's 106+50w idle.
Batteries will work with any inverter just not communicate with it which doesn't do much.
My Quattro 5000w inverter was quiet enough to be next to my bed in my old coach no noise when inverting or charging low volume but there's a fan that kicks in so you can hear it when higher loads.
 
For a mobile RV type vehicle I recommend staying at 12v unless the inverter is 3000+ watts or the solar is 1000+ watts.
What if most of your load usage is 24V with 400W of solar and 200ah of battery. I have a few trade specific items that I could modify to remove the internal transformer and power directly off the 24V. Although these loads are small 65W for 4 hours and 80W for 4 hours per day. So about 580 watts daily I could move from the inverter to the battery directly.

My downside is the same as this post a 24V Victron dc to dc is only 360W and $120 more expensive. Smaller inverters are also hard to find.

Another upside to the 24V is I could use a zero breeze or other 24v A/C if I needed in the mini van for spot cooling.
 
Based on the power consumption you described, I suggest connecting three 12V 300AH batteries in parallel to avoid draining all the power.
 
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