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What guage are the wires going to the inverter. Maybe it's just a scale thing with the picture, but they look like about 2 AWG to me.
They are. The batteries connections are too but I doubled them As I thought they were a bit small. I used what came with the inverter but will likely run a second one on them before long too.
 
From the sources I have you need 0 AWG for short runs on a 24 volt 4,000 watt inverter. For the very short cables between batteries you can probably get away with 2 AWG or even smaller. Resistance is proportional to length.

I have dual 2/0 (00 AWG) cables on my 6,000 watt inverter (12 volt) and 0 AWG cables on my 2000 watt inverter (12 volt). The 6,000 watt inverter has separate connectors for dual cables. One goes to one end of the battery bank and the other goes to the other end.
 
From the sources I have you need 0 AWG for short runs on a 24 volt 4,000 watt inverter. For the very short cables between batteries you can probably get away with 2 AWG or even smaller. Resistance is proportional to length.

I have dual 2/0 (00 AWG) cables on my 6,000 watt inverter (12 volt) and 0 AWG cables on my 2000 watt inverter (12 volt). The 6,000 watt inverter has separate connectors for dual cables. One goes to one end of the battery bank and the other goes to the other end.
According to this chart I’m good. I would Always rather go larger than the minimum size though. My saving grace here is I’m only about 2’ in wire length with stranded copper. I may double the wire later on but would need to get two more inline circuit breakers.
I’m not suprised but was happy to see that with the fridge running all night it didn’t drop the battery capacity noticeably. I will add the freezer in a couple days and then likely a lighting circuit. Since this setup is for the fridge and freezer primarily I won’t max out it’s potential. Saving capacity for cloudy days makes sense. The second system will have a 6000 watt inverter on a 48v battery bank and nothing on it will be critical so I will tie a lot more into it.
 

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I’m still thrilled with the battery monitor! So far the temperature has stayed fine without the need for any fans in the storage area.
 

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D/C current flows through the bulk of a conductor evenly. A/C current flows mainly on the surface. So A/C cables need more surface area than D/C cables.

To visualize this phenomenon, fill a large container with water and stick your open hand in one end of the container and "push" water from one end to the other slowly. Now stick your hand in the middle of the container and try pushing water back and forth as rapidly as you can.
Which has more resistance?
 
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D/C current flows through the bulk of a conductor evenly. A/C current flows mainly on the surface. So A/C cables need more surface area than D/C cables.

To visualize this phenomenon, fill a large container with water and stick your open hand in one end of the container and "push" water from one end to the other slowly. Now stick your hand in the middle of the container and try pushing water back and forth as rapidly as you can.
Which has more resistance?
We have lifts that use 24v systems and all the vehicles use stranded wires. That’s likely for shock and vibration which the solar setup isn’t prone to. I’m honestly far from anything close to an expert on DC systems and was basing this on what I’ve seen in real world applications personally. This whole solar deal is a new adventure for me. Most things in life I’ve done I dove in and figured it out as I went. Kind of a sink or swim thing. So far it’s mostly worked out well without too many costly mistakes. I’ve always said that the second project will turn out better though. Experience is a great teacher.
 
Stranded wires are more flexible. If you have an application like a stationary inverter hooked up to a battery bank, where the cable doesn't need to flex much, then you don't really need stranded. Solid is supposedly cheaper than stranded and smaller in diameter, for obvious reasons.
 
Stranded wires are more flexible. If you have an application like a stationary inverter hooked up to a battery bank, where the cable doesn't need to flex much, then you don't really need stranded. Solid is supposedly cheaper than stranded and smaller in diameter, for obvious reasons.
Not all stranded is flexible either. We have some huge cable that’s 1” without the insulation. I can barely bend it with a large bender, and you can forget about a tight bend! Luckily we don’t deal with too much of the really large stuff.
 
The more I’m learning about inverters I'm seeing that for continuous use it is best to go with the bigger ones that run on higher voltage. The smaller cheaper ones are fine for occasional use (normally, just not that one I got). I’m also learning that the ratings on amazon and eBay aren’t necessarily accurate....
I strongly recommend using the kill a watt meter for anyone considering estimating their power use as it gives you exactly what you use daily. Of course then you need to round up that number for the occasional heavy use or as you said different temperatures or seasons. I rounded up to 4 kWh. I also rounded up my battery storage by double for cloudy days. Basically never design a solar setup for the minimum to run your needs, but give a good bit of extra.

No kidding on most inverters giving you idealistic output power ratings. You are right about higher voltage for better quality inverters. My bigger commercial UPS uses 16 batteries in series, 12v each. So you get about 200 volts DC out of it. But it's output has a 70 or 100 amp / 240 volt circuit breaker. It's a serious unit, but it's also as big as a recliner and nicely fills a corner of a smaller room. But when you need backup power, it'll be there!
 
I’m getting prices from two different solar companies for the next inverter and possibly lithium batteries. Amazon and eBay are fine for smaller inverters but I’m looking for better units for this part. Anyone know a good supplier?
 
With wiring, bigger is ALWAYS better, LOL.

Isn't stranded copper best for A/C? I always though D/C did better with solid.

Don't you have this backwards? You house is wired A/C and the wires in the walls are most likely solid. Generally, either 12 or 14 gauge except for some of your 220v appliances. Your car is D/C and the wires in it are all stranded.

I am not an expert, heck I would not even qualify as an amateur in electricity, so I may be wrong.
 
Don't you have this backwards? You house is wired A/C and the wires in the walls are most likely solid. Generally, either 12 or 14 gauge except for some of your 220v appliances. Your car is D/C and the wires in it are all stranded.

I am not an expert, heck I would not even qualify as an amateur in electricity, so I may be wrong.
It's really only an issue with large diameter cables. The wires in the house and the car aren't thick enough to have what is called a "skin effect" so the primary considerations are economy (solid is cheaper), durability, corrosion resistance, and flexibility without regard to whether it is AC or DC.

With the large inverter cables, you can of course use stranded. Those cables are very expensive because of the amount of copper in them. A solid cable and a stranded cable with the same amount of copper per foot will have the same resistance to DC current but the solid cable will be cheaper. But the solid cable it will have more resistance to AC current. (provided it's large enough to have a "skin effect")

From Wikipedia:

Skin effect is the tendency of an alternating electric current (AC) to become distributed within a conductor such that the current density is largest near the surface of the conductor, and decreases exponentially with greater depths in the conductor. The electric current flows mainly at the "skin" of the conductor, between the outer surface and a level called the skin depth. The skin depth depends on the AC's frequency, with higher frequency resulting in smaller skin depth. The skin effect reduces the effective cross-section of the conductor and thus increases its effective resistance. The skin effect is due to opposing eddy currents induced by the changing magnetic field resulting from the alternating current.​
 
I’ve added the freezer to the inverter now for a couple days. So far the battery capacity hasn’t dropped hardly at all overnight. Soon I will add some other circuits to it. I’m still waiting for a fully overcast day and night to see if there is an appreciable drop first. Since this is for an important duty with the fridge and freezer I want to be careful and not stretch it too much but am certain it can handle more than I’m running so far.
 
A geek commentary on wire gauge/strand-count. The lower the wire gauge, the thicker it is and the more current it can carry. There are tables online for guidelines on how many amps a gauge wire can carry, and they are different for AC and DC circuits (because AC is 120 volts / 240 volts and DC is usually 12 volt... dropping 2 volts on a 240v circuit isn't as important as dropping 2 volts on a 12v circuit).

The second thing is strand count. The more strands in the same gauge wire, the better the current conductivity, but more importantly the more flexible it is. Homes don't move & bounce around, requiring flexibility to avoid breaking. Cars & RVs typically have high-strand counts for maximum flexibility to go around/through things as well as to bounce for 100k miles.
 
I’m getting prices from two different solar companies for the next inverter and possibly lithium batteries. Amazon and eBay are fine for smaller inverters but I’m looking for better units for this part. Anyone know a good supplier?
I bought all my gear through Wholesale Solar. I told them what I needed and they put together the complete package for me. I've been very happy with their service and support.
With my current setup my generator runs an average of 3.5 hours per day over a 12 month period. I don't think that's too bad, but I am planning on adding another 4-5 panels, with a tracker, and a wind generator.
Last week I ordered a 300 gallon diesel tank for the generator. It should arrive next week. Today I ordered propane ($1.42 gal) and I checked on diesel prices $1.74 delivered.
 
I bought all my gear through Wholesale Solar. I told them what I needed and they put together the complete package for me. I've been very happy with their service and support.
With my current setup my generator runs an average of 3.5 hours per day over a 12 month period. I don't think that's too bad, but I am planning on adding another 4-5 panels, with a tracker, and a wind generator.
Last week I ordered a 300 gallon diesel tank for the generator. It should arrive next week. Today I ordered propane ($1.42 gal) and I checked on diesel prices $1.74 delivered.
Wow, great price on diesel!
I called wholesale solar. Their website is the best out there with loads of information. Apparently they are too small though. It took three phone calls before anyone got back to me. Once the guy did return my call He said it would be two weeks before he could email me a design. Hell, all I wanted was a price on an inverter and some battery info on their lithium packs. Hey, I’m glad they are busy but seriously, three weeks on getting info on their products....
 

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