12v or 24v battery

[0truck0]

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.

 

[CampLife]

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?

 

[timm]

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.

 

[CampLife]

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.

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!

 

[Tomthumb62]

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.

 

[Supervstech]

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.

 

[Tomthumb62]

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.