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12v or 24v battery

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.
 
I advise people when getting into the rv lifestyle, to consider becoming an RVer and learn the ways of the force, I mean the ways of camping and RVing. Propane is a wonderful thing, lots of energy stored in the bottle, and though it cost every fillup, there is no up-front cost like on batteries, and appliance can last decades.
Diesel fuel can be used for stoves and heat safely.
GIant fridges and freeezers and high wattage household cookers on a small battery platform? This is not ideal. Great for big rigs with permanent and big solar arrays, yes, electric cooking is way easy, but only if you have the batteries. Seems crazy to do this on folding solar. And, no, that 500watts is not going to cut it.
Did you calculate inverter losses?
Alternators are not magic. You van will not have that much extra available amps to just throw at your dead batteries, and you can easily burn out an alternator using it like this. 60amp DC-DC is way way too much amperage draw on your alternator.
Put a bigger alternator, and Im not sure what the biggest you can fit in your van is, but you can do custom also, but this will also be a power drain on your driving motor and affect mpg's (might not care).
If you have future plans, then do that in the future. It is wise to plan ahead, but in this instance is not the right route.
Sounds like you might be better off buying a small inverter generator (gas generator) and just using that to power your big appliances for 6 hours. IF you plan to live off-grid in future then you will have to have a generator anyway, everyone seems to have a generator, invest in generator as your future.
You will just not be running residential freezers and fridges off your folding panels, and definitely not off your alternator.
Do look heavily at the DC powered fridge/freezers, and DO add extra insulation to them to reduce runtime.
Do look at DC only appliances.
Do consider that you will have to make changes when off the grid.
 
This system is starting off in a minivan but may move to a larger vehicle or possibly even a piece of land. Once I have more space I'll invest in a lot of solar and likely add batteries. That may happen soon after I begin so I'd like something I can grow with.

While in the van I was considering bringing a rocket stove or some sort of camp stove with me. Not sure how practical that is though. Don't know how many city/state parks around the country would allow that. I do most of my cooking in crock pot now and I plan on using that in the van as well. I've watched a bunch of videos on their power draw, and many of the smaller ones are around 100w. I can use one for 7 hours and get 3 days' worth of food out of it (heating up the leftovers on propane). I have a Dometic CoolFreeze cf-25 and when I have the room, I'm getting a dc sunstar chest freezer (not in a minivan). I have an air fryer that I plan on using a couple times a week or as much as the system allows. I'm flexable with the air fryer and will only use it when I have the power to do so. I just want a system that can run a big draw like that efficiently, when I have the power to do so.

I've been working on a wiring diagram and compiling a list of everything I'll need over the past couple days, almost done. However, now I'm getting worried about a few things. First, I was planning on getting an eg4 server rack battery. However, since it'll be in a van with varying temps, dust, moisture and I'll likely be spending a lot of time around the coast, so salt. I'm wondering if an unsealed server rack battery is going to be a bad idea. With all the ports that means dust and moisture will likely be getting in it. I'm now leaning back towards a more common sealed lithium battery.

I'm sold on the kisae dmt2430 dc-dc charger / mppt. It allows you to set the amps it draws from car, so I'll likely keep it at 15-20a to not stress out the van too much. I'll also be installing a kill switch on positive from car battery so during short trips or stop and go, I can keep it off and still allow the kiase to charge using the mppt via the solar on the roof. Many days I'll be driving 6+ hours so I'll use it on days like that and if all works out it should give me plenty of power.

I found 2- 120w 24v solar panels that I'll put in parallel to the mppt. That's about as much as I can fit on the van and I'm hoping to get up to a 1000w a day out of them.

In addition to those two panels, I would like to get some folding panels, but it seems like most are suitable for 12v. I found two folding panels, each with 200w, that I was planning on putting in series. They have these specs: Open Circuit Voltage (Voc): 22.2V, Short Circuit Current (IOC): 12 A, Maximum Power Voltage (Vmp): 18 V, Maximum Power Current (Imp): 11A, Solar Energy Conversion Rate: 19%-22%.

I'm not sure how realistic that is though. Under normal conditions how tough will it be to keep the volts high enough to charge a 24v battery using two 200w folding panels? I read somewhere that about 25% shade or cloud coverage to them may reduce the voltage to a point where it won't be able to charge a 24v battery. Does that sound about right? If so, seems like a slim margin for error. Also, I imagine they'll degrade and likely produce less output in a few years, could that mean that they'll no longer be able to charge a 24v battery? I also came across 1 folding solar panel with 400w, max power of 10.6a, and max voltage of 37.4v but am also wondering, like with the two 200w folding panels in series, how difficult it will be to keep the volts high enough to charge a 24v battery?
 
This system is starting off in a minivan but may move to a larger vehicle or possibly even a piece of land. Once I have more space I'll invest in a lot of solar and likely add batteries. That may happen soon after I begin so I'd like something I can grow with.

While in the van I was considering bringing a rocket stove or some sort of camp stove with me. Not sure how practical that is though. Don't know how many city/state parks around the country would allow that. I do most of my cooking in crock pot now and I plan on using that in the van as well. I've watched a bunch of videos on their power draw, and many of the smaller ones are around 100w. I can use one for 7 hours and get 3 days' worth of food out of it (heating up the leftovers on propane). I have a Dometic CoolFreeze cf-25 and when I have the room, I'm getting a dc sunstar chest freezer (not in a minivan). I have an air fryer that I plan on using a couple times a week or as much as the system allows. I'm flexable with the air fryer and will only use it when I have the power to do so. I just want a system that can run a big draw like that efficiently, when I have the power to do so.

I've been working on a wiring diagram and compiling a list of everything I'll need over the past couple days, almost done. However, now I'm getting worried about a few things. First, I was planning on getting an eg4 server rack battery. However, since it'll be in a van with varying temps, dust, moisture and I'll likely be spending a lot of time around the coast, so salt. I'm wondering if an unsealed server rack battery is going to be a bad idea. With all the ports that means dust and moisture will likely be getting in it. I'm now leaning back towards a more common sealed lithium battery.

I'm sold on the kisae dmt2430 dc-dc charger / mppt. It allows you to set the amps it draws from car, so I'll likely keep it at 15-20a to not stress out the van too much. I'll also be installing a kill switch on positive from car battery so during short trips or stop and go, I can keep it off and still allow the kiase to charge using the mppt via the solar on the roof. Many days I'll be driving 6+ hours so I'll use it on days like that and if all works out it should give me plenty of power.

I found 2- 120w 24v solar panels that I'll put in parallel to the mppt. That's about as much as I can fit on the van and I'm hoping to get up to a 1000w a day out of them.

In addition to those two panels, I would like to get some folding panels, but it seems like most are suitable for 12v. I found two folding panels, each with 200w, that I was planning on putting in series. They have these specs: Open Circuit Voltage (Voc): 22.2V, Short Circuit Current (IOC): 12 A, Maximum Power Voltage (Vmp): 18 V, Maximum Power Current (Imp): 11A, Solar Energy Conversion Rate: 19%-22%.

I'm not sure how realistic that is though. Under normal conditions how tough will it be to keep the volts high enough to charge a 24v battery using two 200w folding panels? I read somewhere that about 25% shade or cloud coverage to them may reduce the voltage to a point where it won't be able to charge a 24v battery. Does that sound about right? If so, seems like a slim margin for error. Also, I imagine they'll degrade and likely produce less output in a few years, could that mean that they'll no longer be able to charge a 24v battery? I also came across 1 folding solar panel with 400w, max power of 10.6a, and max voltage of 37.4v but am also wondering, like with the two 200w folding panels in series, how difficult it will be to keep the volts high enough to charge a 24v battery?
I'm hoping to test that myself soon when I can get some time. The manual for the Kisae says it will accept power from solar down to 15v and still charge a 24v battery.
 
Hello everyone, I'm getting ready to build my system this week. I have bought most of the major components but still need to get the wires, fuses, on/off switches etc.

I ended up purchasing a 24v 200ah eg4 v2 from signature solar, a Kisae 30a DC to DC charger, a Kisae 24v 2000w inverter an the allpowers 400w solar panel.

I've attached a diagram with the set up I was planning. I already have some 2ga wire from a previous battery bank I had a few years ago. I'd like to use that if possible, from battery to inverter it will be less than 5', so it seems like that wire should be sufficient but I am considering using 1ga wire. solar-set-up-2.jpg

Let me know if you notice any mistakes or things I overlooked when making the diagram. Also, let me know if there is anything you'd do different. Any help is appreciated!
 
Hello everyone, I'm getting ready to build my system this week. I have bought most of the major components but still need to get the wires, fuses, on/off switches etc.

I ended up purchasing a 24v 200ah eg4 v2 from signature solar, a Kisae 30a DC to DC charger, a Kisae 24v 2000w inverter an the allpowers 400w solar panel.

I've attached a diagram with the set up I was planning. I already have some 2ga wire from a previous battery bank I had a few years ago. I'd like to use that if possible, from battery to inverter it will be less than 5', so it seems like that wire should be sufficient but I am considering using 1ga wire. View attachment 159107

Let me know if you notice any mistakes or things I overlooked when making the diagram. Also, let me know if there is anything you'd do different. Any help is appreciated!

2000W/24v/0.85 = 98A

Depends upon the temperature rating of your 2 AWG. If it’s only 60c, then it’s not enough. 0 AWG would be the right choice. For a 3% or less voltage drop at 100A continuous.

But if it’s 105c rated, then 3 AWG would suffice, so 2 AWG would be even better.

The temperature rating is printed on the insulation of quality cable. If it’s not, then assume 60c.
 
2000W/24v/0.85 = 98A

Depends upon the temperature rating of your 2 AWG. If it’s only 60c, then it’s not enough. 0 AWG would be the right choice. For a 3% or less voltage drop at 100A continuous.

But if it’s 105c rated, then 3 AWG would suffice, so 2 AWG would be even better.

The temperature rating is printed on the insulation of quality cable. If it’s not, then assume 60c.
True,BUT 105C means it is capable of handling that temp...

Wiring jobs should NEVER size conductors for use at the 105C rating...
Heat is WASTES WATTAGE AND CAUSES VOLTAGE DROP...
Size the wire for the coolest operation...
Not what the insulation can handle.
 
True,BUT 105C means it is capable of handling that temp...

Wiring jobs should NEVER size conductors for use at the 105C rating...
Heat is WASTES WATTAGE AND CAUSES VOLTAGE DROP...
Size the wire for the coolest operation...
Not what the insulation can handle.
I agree completely, your way is better. But more expensive. What I suggested is standard and won’t cause a fire.

I used the Blue Seas wiring calculator. The wire suggested is rated for 136A. OP will max out at 96A. So there is quite a bit of wiggle room. Plus with only a 3% voltage drop, I can’t imagine the wire heating up all that much. But you’re right, bigger is better if money isn’ta concern.
 

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