Be patient with the new/ignorant guy!

[kjswiley]

I am also quite new to this all so keep that in mind while I give my noob advice.

Regarding AC use-Max out your Solar, this is more important than batteries in the following scenario:

With my inverter I can use solar as the priority, feeding the loads directly. Lets say my AC uses 1500W, when I run AC on a sunny day, my battery bank is unaffected as the shunt shows me using 200W, since 1300W of the AC demand are being directly provided via the inverter by solar....the batteries do not care about that. I can run the AC all day provided it is sunny, and only lose a little power to my normal loads (Fridge, Laptop, Lights). Obviously if you do not have sun you cannot keep up, so your location will play a factor. When I shut down my solar array, my shunt will update from several days worth of power to about 6hrs max if I were to run AC on batteries only, so using batteries to run AC is not very feasible in my mind.

I have 4 residential panels = 2120W solar.
8 12V 100 ah Batteries in 4S2P. I have 8 as I will put these into a to be built house, you probably do not "need" 8.

edit: seems this aligns with rmaddys post which I had not yet seen. I agree get a mini-split AC if you can, I did not know about them before I purchased a new RV AC, but wish I had gone that route instead.

 

[Ziggy With It]

BTW - consider a mini split A/C instead of a rooftop model. They tend to be far less power hungry, quieter than window units, and they don't take up any roof space.

Hmmmmmmm. Hadn't thought of that. Is that what you have? Are there pics of how you have it mounted?

 

[rmaddy]

Hmmmmmmm. Hadn't thought of that. Is that what you have? Are there pics of how you have it mounted?

I don't have a mini split. I have a regular window mounted A/C unit. I didn't really know about mini splits when I was planning. If you search Youtube you should find a few videos of people mounting mini splits in cargo trailers.

 

[GLC]

BTW - consider a mini split A/C instead of a rooftop model. They tend to be far less power hungry, quieter than window units, and they don't take up any roof space.

Very true, I recently put one in our master bedroom to run off of solar. Start up amps was 11, running amps was around 4 to 5 amps.

 

[Rednecktek]

Very true, I recently put one in our master bedroom to run off of solar. Start up amps was 11, running amps was around 4 to 5 amps.

8k BTU?

 

[GLC]

8k BTU?

1 ton, 12,000 BTU, 110 volt, heat and cool.

 

[Rednecktek]

1 ton, 12,000 BTU, 110 volt, heat and cool.

Ooohhh.... link? I'll add it to my shopping list for the camp!

 

[Ziggy With It]

Oh Lawwwwwwwwwwwd! I just started corresponding with somebody who has me totally rethinking everything I've somewhat decided on. Here's what he's saying: Since I won't have enough panels to charge the 48V system, I should go with 12V/400ah and turn that into 24V to run through the inverter. Also would require something apparently called a dc-dc box? So I looked up that battery and 24v inverter on Signature Solar and it actually has a 3000w inverter instead of the 2000w in the 48V system. What do you guys think about this new direction? I mean I totally do not mean to discount all of the fantastic information you guys have given me. But it actually makes sense to me.

Oh, and he agrees with the minisplit.

 

[rmaddy]

I skimmed back through the thread and I didn't see where you committed to a 48V battery. My cargo trailer camper is 24V. I see no reason for 48V in a trailer. You will have a lot more options for fuses, breakers, switches, etc. that will work on a 24V (nearly 29V in reality) system. It's harder to find stuff for 48V (nearly 58V really).

The only reason you might want 48V is if you need an inverter much bigger than 3000W or you need more solar than will fit on the trailer roof. 48V lowers the amps on both of those. But 24V works just fine for a 3000W inverter and a lot of solar. Though if you were thinking of a 2000W inverter at 48V, why go up to 3000W if you go with 24V? If 2000W was enough at 48V then it is still enough at 24V.

Also keep in mind that if you were to buy 4 12V 100Ah batteries you could configure them in 2S2P for a 24V 200Ah system or in 4S for a 48V 100Ah system. In both cases you still have 5kWh of battery so either way you can run the same amount of stuff on a given day.

 

[Ziggy With It]

Okay, I'm miscommunicating again. I'll try to clear things up. I didn't actually commit to 48V. I was leaning heavily in that direction since Will had said in a recent video that it was actually cheaper. I think that may have changed again as I'm seeing pretty much the same prices now for 24V and 48V.

The guy I've been corresponding with is saying that I should get two 12V SOKs and he'll give me the diagram to make it 24V. He's pricing the 2 12V/206AH batteries at $2060. I didn't know that the 48V would require more power than I can produce with the amount of space I have available for panels. I'm looking at 4 panels in the 430-455 range. This would run me ~$1000 ($249 X 4) from Signature for 455W panels and $1200 from the guy for 430W panels. He's pricing a Growatt @ $680 and Signature has them (I guess it's the same unit but not sure) for $659. Oh, and I'm close enough to Signature Solar to drive over there and pick up anything I buy from them.

You bring up another question, though. Okay, so "the guy" is at $2060 for two 206AH batteries and a 24V/200AH EG4 is $1499. You made it sound like the 412AH would reduce to 206AH into the inverter. So, basically the same AH but the EG4 would be $500+ cheaper and would be only one battery instead of 2. Am I comprehending?

The "reason for" the 2000W inverter is that it was the Growatt that was available in 48V. I feel more comfortable with 3000 which I might not ever completely use, but I "feel like" it would be nice to have the extra available. Also, that's the unit that's available from Signature.

Now, on to the minisplit. My friend came over today and told me to figure out how big of a unit I'll need and to not buy the bigger unit. I was thinking bigger is better and the price difference from 9000 BTU to 12,000 BTU is only $100. So my thought was to buy the bigger unit and it would just run at a rate that would be easier for it than a smaller unit. He said my thinking is wrong. So, is it better to go bigger and not use it to its full capability or not?

Thanks again for all the help!

 

[rmaddy]

I didn't know that the 48V would require more power than I can produce with the amount of space I have available for panels.

That's simply not true. A 24V 200Ah battery bank or a 48V 100Ah battery bank has the same amount of power and requires the same amount of solar to recharge.

The guy I've been corresponding with is saying that I should get two 12V SOKs and he'll give me the diagram to make it 24V. He's pricing the 2 12V/206AH batteries at $2060.

You can buy the same two batteries directly from SOK for the same price. Wiring them in series for 24V is trivial.

Okay, so "the guy" is at $2060 for two 206AH batteries and a 24V/200AH EG4 is $1499. You made it sound like the 412AH would reduce to 206AH into the inverter.

2 12V 206Ah batteries in series for 24V would be 206Ah. The inverter is irrelevant for that. So you pay $2060 for the SOK to get 24V 206Ah or you pay $1499 for the EG4 to get 24V 200Ah. Keep in mind that the rack batteries are supposed to be a poor choice for a mobile application.

So, basically the same AH but the EG4 would be $500+ cheaper and would be only one battery instead of 2. Am I comprehending?

Correct except the rack battery isn't a good choice for mobile.

I can't address the mini split question.

 

[GLC]

Ooohhh.... link? I'll add it to my shopping list for the camp!

Locally here you can purchase them between 300 and 500 dollars. You can install yourself.

 

[GLC]

Okay, I'm miscommunicating again. I'll try to clear things up. I didn't actually commit to 48V. I was leaning heavily in that direction since Will had said in a recent video that it was actually cheaper. I think that may have changed again as I'm seeing pretty much the same prices now for 24V and 48V.

The guy I've been corresponding with is saying that I should get two 12V SOKs and he'll give me the diagram to make it 24V. He's pricing the 2 12V/206AH batteries at $2060. I didn't know that the 48V would require more power than I can produce with the amount of space I have available for panels. I'm looking at 4 panels in the 430-455 range. This would run me ~$1000 ($249 X 4) from Signature for 455W panels and $1200 from the guy for 430W panels. He's pricing a Growatt @ $680 and Signature has them (I guess it's the same unit but not sure) for $659. Oh, and I'm close enough to Signature Solar to drive over there and pick up anything I buy from them.

You bring up another question, though. Okay, so "the guy" is at $2060 for two 206AH batteries and a 24V/200AH EG4 is $1499. You made it sound like the 412AH would reduce to 206AH into the inverter. So, basically the same AH but the EG4 would be $500+ cheaper and would be only one battery instead of 2. Am I comprehending?

The "reason for" the 2000W inverter is that it was the Growatt that was available in 48V. I feel more comfortable with 3000 which I might not ever completely use, but I "feel like" it would be nice to have the extra available. Also, that's the unit that's available from Signature.

Now, on to the minisplit. My friend came over today and told me to figure out how big of a unit I'll need and to not buy the bigger unit. I was thinking bigger is better and the price difference from 9000 BTU to 12,000 BTU is only $100. So my thought was to buy the bigger unit and it would just run at a rate that would be easier for it than a smaller unit. He said my thinking is wrong. So, is it better to go bigger and not use it to its full capability or not?

Thanks again for all the help!

On the mini split unit, you can buy what is available in your area. Base the size of your unit on the sq feet you will be heating and cooling. A 12,000 btu unit will handle 500 aq ft. I installed my 12000btu unit in a 180 sq ft room. It works fine. Normally the consequences of mis-matching a hvac unit to the space is this: unit too small will run more and also take more humidity out of the air. Unit too large it will run less often and also take less humidity out of the air. Either way it is not a deal breaker. In my area the smallest one at the price I wanted was the 12000 btu 110 unit. Since it was affordable, low amp draw and easy to install, I chose that one. Find the one with the least amp draw- most efficient and go with it if it at least matches your sq footage you are putting it in.

 

[Ziggy With It]

That's simply not true. A 24V 200Ah battery bank or a 48V 100Ah battery bank has the same amount of power and requires the same amount of solar to recharge.


You can buy the same two batteries directly from SOK for the same price. Wiring them in series for 24V is trivial.


2 12V 206Ah batteries in series for 24V would be 206Ah. The inverter is irrelevant for that. So you pay $2060 for the SOK to get 24V 206Ah or you pay $1499 for the EG4 to get 24V 200Ah. Keep in mind that the rack batteries are supposed to be a poor choice for a mobile application.


Correct except the rack battery isn't a good choice for mobile.

Okay. You've seen me flip-flopping for months now. And I still haven't bought anything because I want to be sure that I only do this once with the correct equipment. In his newest correspondence, the guy has pointed out that the SOKs are sealed waterproof batteries made for marine environments. He also agrees with you that the rack batteries are a poor choice for a mobile application. So it looks like the SOK marine batteries are the way to go.

Now on to the panels. Are the 4 430W panels sufficient?

 

[Ziggy With It]

On the mini split unit, you can buy what is available in your area. Base the size of your unit on the sq feet you will be heating and cooling. A 12,000 btu unit will handle 500 aq ft. I installed my 1000btu unit in a 180 sq ft room. It works fine. Normally the consequences of mis-matching a hvac unit to the space is this: unit too small will run more and also take more humidity out of the air. Unit too large it will run less often and also take less humidity out of the air. Either way it is not a deal breaker. In my area the smallest one at the price I wanted was the 12000 btu 110 unit. Since it was affordable, low amp draw and easy to install, I chose that one. Find the one with the least amp draw- most efficient and go with it if it at least matches your sq footage you are putting it in.

Thanks! I have 98 square feet.

 

[rmaddy]

the guy has pointed out that the SOKs are sealed waterproof batteries made for marine environments.

That’s an option. You can buy the non-marine version.

Now on to the panels. Are the 4 430W panels sufficient?

I have two SOK 12V 206Ah batteries and my 990W of solar is plenty if there is sun. 1720W is plenty.