Upgrades, People, Upgrades

[Wavery]

Originally Posted by Autosnap

I think I was concerned about pushing 800w in 12v from the solar controller. I know it'll never actually get there so I went with 60amps, so you think I need to go with 4awg?

I forgot to address this question.

The MPPT solar controller will manipulate the volts, amps and watts coming from the solar panels to give the battery bank what it needs for the most efficient charging. It wouldn't be uncommon for your controller to put out more amps than the collective amperage (~40A) coming from the panels. However, 6AWG wire should be quite sufficient.

On my system, I fused my solar panels with inline MC4 fuses at each panel.
https://www.amazon.com/BougeRV-Contr...00&sr=8-2&th=1

I also installed a PV circuit breaker between the solar panels and the controller, mainly so that I could turn off the current from the panels to the controller for maintenance purposes. Like, if you ever shut off your battery switch, you want to shut off the solar first. Then (when your done) turn on the battery switch first, then the solar breaker. The solar controller needs to read the battery voltage first. Doing it wrong can damage some solar controllers.


You are going to need some special tools for this project as well. You'll need cable cutters (for the 4/0 wire), wire strippers, 6AWG-4/0AWG Hydraulic Cable Lug Crimper (or it's cheaper manual counterpart), heat gun, Ferrule Crimping Tool Kit, heat gun.

I find using wire end ferrules on the smaller wires (10G and smaller) to be extremely helpful for the cleanest, easiest and best connections when inserting wires into devices like the solar controller, PD charger, fuse panel, ATS,,,, anywhere that you have a bare wire end. The ferrule just crimps on the end of the wire so that you don't have straggler wire strands. It makes the whole job so much easier and faster.

[Autosnap]

Originally Posted by jagizzi

Another consideration if you are going to be that far into it. I wanted individual control of every DC circuit so that I could turn them on and off as needed. The Converter fuse panel was abandoned and I added a Blue Seas DC Breaker Panel. https://www.bluesea.com/products/8376/DC_13_Position. If fit beside the converter once I moved the converter over a bit. Great addition to the electrical system and I would do it again. No need to run any new wires as you are simply replacing the existing fuse panel.

I did something similar with the batteries but kept the LA up front for back up and to run the tongue jack. Also added battery string selection switch and cutoff. Added a photo of battery bay in an early phase.
Note that when you move the batteries to the rear compartment you need to take the emergency trailer brake system into account and run that line back to the batteries before any disconnect switch.

Thanks Jim,

I don't plan to go all that far, I think I'll replace the battery cable with sufficient wire to run a Tongue Jack when I add one... That's right, mine came with bells and whistles, but I'm still cranking her up and down myself, or using 13 y/o arm power.. LOL Don't worry the boy is fine with it.

I'll keep the emergency break controller in mind, but I don't think it goes to the battery directly anyway. At least on mine. I'll keep an eye out! Thanks for the tip.

Best,
Brad

[Autosnap]

Originally Posted by Bill

Be aware that circuit breakers can have different ratings when used on DC circuits rather than AC circuits. This has to do with the fact that AC voltage and current waveforms go through zero 120 times per second, and this helps the circuit breaker properly interrupt the circuit. DC waveforms do not go through zero, so the breaker has to handle the worst-case fault by itself.

When you choose a breaker for a DC circuit, be sure to check its DC ratings. An inexpensive household breaker may not meet your need.

Bill

Thanks to you and Wavery I've watched a few horrifying videos on tests of those breakers. You really have to pay attention to what you get.

[Autosnap]

Ok, Stab 2 Thanks again for all the great input.

I'm starting to think I could have left the original Converter, unhooked it and wired in a new standard Lithium Charger (cheaper than buying the PD4655WL), but at least now I have the ability to wire it back if ever I need to.

Still haven't filled out the DC Fuse box/Distribution area, plus I need to figure out where the TV Cable goes, but I'll get to it hopefully tomorrow, was busy today.

Thanks again for everyone's consideration! Rick, you out there? I would appreciate your input as well if you have the time!

[Autosnap]

Feeling kinda Sheepish... Forgot the files.. LOL

[rickst29]

A single "200W" ion the rear shell is easy, even for a 2619. But you can't do 3 panels on the front shell that way, because the AC unit and vents (and maybe an antenna mast as well) make things more difficult.

You also show all panels wired in parallel, (low voltage, high current). If you could wire 2S-2P, or even all 4 in series, your late-day and early morning results results would be better - and you would not need as many wires.

In 2S-2P, you total voltage is onlhy around 60 volts and a 100 volt MPPT unit would be OK. But in In 4-S, V(oc) would get up to about 120 volts, maybe higher in cold conditions. You would want to buy a reputable brand "150 volt" controller for that. AWG-10 or even AWG-12 solar wire would work fine for either of those lower current implementations.



Your notion of 3 small batteries is wasteful and more costly than one big one. (You have more points of failure, lots more wires and connections, it's a mess. I know about this -- I have 3 "battery packs", and the wires are a mess. (Mine are 270AH, 220AH, and 200AH, but two packs of 300+ each would have been a lot better for me as well. 3 different BMS units to monitor and configure, it's not entirely fun.

I do not use a single 4/0 wire to carry the current of all 3 battery packs to the shunt - I my stack separate 2/0 terminals on the shunt bolt, with great results. From my "+" battery fuses, I go directly to the Inverter: A "busbar" with 300A in and 300A out is a 600A bus bar, they don't make them that big.

You can also bolt multiple terminal lugs into the "DC" power bus bars on the input side of any decent high powered "12-Volt DC input" Inverter, that also allows you to use multiple smaller cables instead. Keep those cables SHORT!

[Wavery]

Originally Posted by Autosnap

Feeling kinda Sheepish... Forgot the files.. LOL

That looks a lot better but you can connect your front and rear solar panel pairs before the PV circuit breaker using branch connectors. You want only one PV breaker. It's a double breaker with a pos & neg pole (in and out).

https://www.amazon.com/dp/B07DJ5PHSB...onnectors&th=1

https://www.amazon.com/Miniature-Cir...1zcF9hdGY&th=1

[Wavery]

Here's a few suggestions. That Class T fuse should go between the battery switch and the battery. It is your last ditch protection to cover you for any catastrophic short, including the internal connectors of the shut-off switch.

I made a few other suggestions. You can put a switch between the solar controller and pos busbar if you want but I can't imagine what it would be used for. The fuse is important.

BTW..... I have been meaning to ask you, why such a large system? Do you plan to run the A/C off of this.

My current set-up is 640W of solar and 230ah of (single) battery. I never run out of power and we use electricity like we do at home (except no A/C). If we boondock in the heat, we run the generator. There is no way that you have enough room to put a system big enough to run your A/C for any decent amount of time. The guys that do that have 5KW of solar, 2-3 Victron Multiplus inverters and about 5,000AH of batteries. That's about $15,000 in parts and normally on huge motorhomes or trailers.

[rickst29]

Originally Posted by Wavery

Here's a few suggestions. That Class T fuse should go between the battery switch and the battery. It is your last ditch protection to cover you for any catastrophic short, including the internal connectors of the shut-off switch.

I made a few other suggestions. You can put a switch between the solar controller and pos busbar if you want but I can't imagine what it would be used for. The fuse is important.

BTW..... I have been meaning to ask you, why such a large system? Do you plan to run the A/C off of this.

My current set-up is 640W of solar and 230ah of (single) battery. I never run out of power and we use electricity like we do at home (except no A/C). If we boondock in the heat, we run the generator. There is no way that you have enough room to put a system big enough to run your A/C for any decent amount of time. The guys that do that have 5KW of solar, 2-3 Victron Multiplus inverters and about 5,000AH of batteries. That's about $15,000 in parts and normally on huge motorhomes or trailers.

I agree with Wavery, that a single battery of 230AH or 270Ah will be sufficient for everything except the Air Conditioner. Don't use multiple tiny batteries.

My Solar is 'only' rated at 800 watts (200W rear, 600W front), and my batteries are 'only' about 700Ah total - but I can run the the Air Conditoner for at least a few hours in the late day, when the sun shines.

I own a small propane-only generator, but haven't used in camping - it's a "reserve" capability for recharging the batteries on cloudy days. It can't run the Air Conditioner, but it's lighter to carry than yours.

[Autosnap]

Originally Posted by rickst29

A single "200W" ion the rear shell is easy, even for a 2619. But you can't do 3 panels on the front shell that way, because the AC unit and vents (and maybe an antenna mast as well) make things more difficult.

I've done some preliminary layouts and it seems to work. Real life my throw me a monkey wrench, and in that case I'll drop back and punt. Please see Roof "PV Layout.pdf" My major concern is it adding 75 lbs to the roof of the front shell. I certainly don't want to break something VERY important.

Originally Posted by rickst29

You also show all panels wired in parallel, (low voltage, high current). If you could wire 2S-2P, or even all 4 in series, your late-day and early morning results results would be better - and you would not need as many wires.

In 2S-2P, you total voltage is onlhy around 60 volts and a 100 volt MPPT unit would be OK. But in In 4-S, V(oc) would get up to about 120 volts, maybe higher in cold conditions. You would want to buy a reputable brand "150 volt" controller for that. AWG-10 or even AWG-12 solar wire would work fine for either of those lower current implementations.

For some stupid reason I thought I had it 2s-2p. This is precisely what I want so if the two aft PV's are shaded that the two fore PV's might be able to charge and vice versa. Should be fixed now? Are you supposed to use the Voc for calculations? I have a 150V SCC anyway

Originally Posted by rickst29

Your notion of 3 small batteries is wasteful and more costly than one big one. (You have more points of failure, lots more wires and connections, it's a mess. I know about this -- I have 3 "battery packs", and the wires are a mess. (Mine are 270AH, 220AH, and 200AH, but two packs of 300+ each would have been a lot better for me as well. 3 different BMS units to monitor and configure, it's not entirely fun.

I understand, but I already have them from a friend, the BMS units aren't readable from Bluetooth anyway, so it is what it is, and they will last as long as they last. I'll be getting as much information as I can from the shunt.

Originally Posted by rickst29

I do not use a single 4/0 wire to carry the current of all 3 battery packs to the shunt - I my stack separate 2/0 terminals on the shunt bolt, with great results. From my "+" battery fuses, I go directly to the Inverter: A "busbar" with 300A in and 300A out is a 600A bus bar, they don't make them that big.

Yup, I had already been looking at that, and I forgotten what goes in must come out. So Straight to the battery from the SCC?

I have a metric button of 4/0 copper wire so, I'm going to give it a go. I may regret it, but at least I didn't have to source cable.

Originally Posted by rickst29

You can also bolt multiple terminal lugs into the "DC" power bus bars on the input side of any decent high powered "12-Volt DC input" Inverter, that also allows you to use multiple smaller cables instead. Keep those cables SHORT!

I'll spread the positives out making sure we don't have issues.

Thanks for taking a look this really clarified the solar section for me! I'll be modifying the drawing this weekend. Please take another look when you get a chance.