Solar Show and Tell

[Fair_Enough]

Originally Posted by TouringDan

Clint

The MC4s hanging below the trailer is how I connect the portable panels to my solar controller. The short pigtail goes from the MC4s to the controller.Attachment 335059
You are correct, when you divide 208 watts by 13.58 volts, you get 15.3 amps which exceeds the 15 amp perceived rating. I am not concerned since the manufacturer states that the controller is good for 220 watts @ 12v. This is over 18 amps. Obviously some margin is built into the controller to handle situations like I experienced where the panels were putting out more than their rated power.

DanAttachment 335060

Thanks Dan,
That is what my SC2030 will do also, limits throughput if current exceeds rated amps.
Clint

[Meddle]

Hi everyone, I am adding a panel to my PV system and upgrading my battery bank from two 105AH AGM to four 100AH LiFePO4.

In doing so, I plan to move the batteries from outside to the storage area under the bed. I think I will also take this opportunity to rewire the PV controller, batteries, inverter and a few other DC components such as the LP detector.

I am looking for advice or feedback on how I have diagramed my upgrade --anything in terms of things I may have overlooked or components I've included that aren't needed. For example, one thing I'm not sure of is whether 1 GA wire is overkill and 2 or 4 GA wire would be sufficient.

Thanks, everyone!

[wulfraat]

1ga is overkill for standard 12v loads and a 600w inverter but I would not go any less, to future proof your install if you want to move to a larger inverter at some point.

[Fair_Enough]

Nice drawing Meddle.

You are "missing" protection / breaker on the 12vdc supply side of the inverter and one on the battery side of the MPPT, IMO.

If the inverter can make 1200W surge, the breaker somewhere between there and batteries should be in the order of around 100 / 120 amps DC. 1 AWG doesn't seem like enough.

Also, check with product information, because I doubt you can terminate a 1 AWG at the MPPT (gauge seems overly large) and possibly not onto the Inverter without a proper method.

Plugging 100A into a VD calculator shows to attain less than 1% you will need #1/0 (inverter to batteries) for 6 feet of total one-way wire run.

You are not showing the Converter or the frame ground.

I also question the need for a temperature probe. Depending on the batteries you use, the BMS should take care of all that.



Edit: I would wire MPPT Inverter to the (+) buss. with proper sized breakers / fuses and battery cut off switches.


Hopefully a true expert will chime in.
Clint

[pdavitt]

Originally Posted by Meddle

Hi everyone, I am adding a panel to my PV system and upgrading my battery bank from two 105AH AGM to four 100AH LiFePO4.

In doing so, I plan to move the batteries from outside to the storage area under the bed. I think I will also take this opportunity to rewire the PV controller, batteries, inverter and a few other DC components such as the LP detector.

I am looking for advice or feedback on how I have diagramed my upgrade --anything in terms of things I may have overlooked or components I've included that aren't needed. For example, one thing I'm not sure of is whether 1 GA wire is overkill and 2 or 4 GA wire would be sufficient.

Thanks, everyone!

Before anyone here can help you need much more information:

1. Make and Model of your batteries
2. Make and Model of your Battery Monitor
3. Make and Model of your Solar Charge Controller
4. Make and Model of your Solar Panels
5. Make and Model of your Inverter

Something seems off, most LFP batteries are capable of absorbing and producing 1C, which means 4 100Amp Hour batteries, in parallel, are capable of producing 400 Amps of current. Please give us some more information to go on.

Thanks,
Pat

[Meddle]

Originally Posted by pdavitt

Before anyone here can help you need much more information:

1. Make and Model of your batteries
2. Make and Model of your Battery Monitor
3. Make and Model of your Solar Charge Controller
4. Make and Model of your Solar Panels
5. Make and Model of your Inverter

Sorry Pat, was trying to keep the diagram make/model agnostic to make it as straight forward as possible.

1. Batteries - Battle Born 100Ah 12V LiFePO4 Deep Cycle
2. Battery Monitor - Bogart TM-2030-A-F TriMetric
3. PV Controller - Blue Sky Solar Boost 3000i
4. PV Panels - AM Solar: (2) W135GS + (1) ZS90L
5. Inverter - WFCO 600W Pure Sine Wave WF-600TH
6. Converter (not diagramed) - PD4655V

[Meddle]

Originally Posted by Wolfwhistle

You are "missing" protection / breaker on the 12vdc supply side of the inverter and one on the battery side of the MPPT, IMO.

If the inverter can make 1200W surge, the breaker somewhere between there and batteries should be in the order of around 100 / 120 amps DC. 1 AWG doesn't seem like enough.

Also, check with product information, because I doubt you can terminate a 1 AWG at the MPPT (gauge seems overly large) and possibly not onto the Inverter without a proper method.

Thank you, Wolfwhistle. These are excellent points you bring up. And you are correct about the 1 AWG not fitting for the MPPT and inverter. It looks like the largest I can go is 4 GA. I highlighted changes to the diagram. I think I am following you on the breaker positioning (makes sense when I think about it) but want to be sure that's what you meant.

Thanks again. This kind of help is what makes this community so special!

[TouringDan]

Meddle

Looks like you are in great shape with comments from the folks that know.

I have completed my upgrade but I am sure I probably need to make some changes, but I don’t have a nice wiring drawing like you have. What software did you use?

Thanks, Dan

[Meddle]

Originally Posted by TouringDan

What software did you use?
Thanks, Dan

I used Adobe Illustrator for this.

[uncle_bob]

Originally Posted by Meddle

Hi everyone, I am adding a panel to my PV system and upgrading my battery bank from two 105AH AGM to four 100AH LiFePO4.

In doing so, I plan to move the batteries from outside to the storage area under the bed. I think I will also take this opportunity to rewire the PV controller, batteries, inverter and a few other DC components such as the LP detector.

I am looking for advice or feedback on how I have diagramed my upgrade --anything in terms of things I may have overlooked or components I've included that aren't needed. For example, one thing I'm not sure of is whether 1 GA wire is overkill and 2 or 4 GA wire would be sufficient.

Thanks, everyone!

Hi

Two 100AH AGM's give you 100AH net usable capacity. Four 100AH Lithiums give you 400AH net usable capacity (for a *lot* more money). If indeed the credit card is happy both ways, the higher capacity likely will be of more use to you.

Wire wise, the inverter capacity is most likely to be the big factor. The bigger the inverter the larger the wire. Run length also matters a bit. Yes, you *could* put in a 5,000W solar array or a 400A converter / charger. Most people don't do that ....

Since things like inverter size and the rest relate back to battery capacity (and type), this all is an interactive problem. Change one thing and that likely impacts the rest of the system.

So is $4,000 for the lithium's in the budget? Unless some solar is involved, that's at least 2/3 of what this will cost on a DIY basis.

Bob

[AirMiles]

Meddle, your revised diagram looks good to me.

I am wondering why 400AH of Lithium? That's a huge battery bank for a 600W inverter and typical Airstream loads, especially when you have solar that will be recharging the battery bank each day. I typically use about 100AH per day when running my furnace all night and typical Airstream loads. With a 400AH battery bank, I could boondock for four days in complete shade with 50 degree temperatures. If I had 400W of lithiums, I'd install at least a 2000W inverter so I could run my microwave and my wife's hairdryer. To me, something seems out of balance with the battery bank and inverter size.

Also why a mix of solar panels? Wouldn't four 100W panels fit on the four corners of your roof like I have on my FC25FB? (picture here: http://www.airforums.com/forums/f448...ml#post2102019 ) Do MPPT controllers prefer matching panels so the most efficient Maximum Power Point can be utilized for all the panels? I would use matching panels if possible on the roof.

[TouringDan]

Meddle

If you are sure that you want the capacity of 400 AH then of course go with it. If you aren’t sure then maybe start with 200 AH or even 100 AH, you can add more capacity easily later. It doesn’t affect the design of your planned modifications.

Dan

[Meddle]

Originally Posted by AirMiles

I am wondering why 400AH of Lithium? That's a huge battery bank for a 600W inverter and typical Airstream loads, especially when you have solar that will be recharging the battery bank each day.

Also why a mix of solar panels? Wouldn't four 100W panels fit on the four corners of your roof like I have on my FC25FB?

Hi AirMiles, we hardly have a need for the inverter, in fact I think we've powered it up maybe twice in 6 years. It came with the trailer, but everything we run is 12V. I figure I'd keep it and wire it in just in case the occasional need does come up.

I have two 135W AM Solar PVs already, but AM Solar isn't making that panel anymore, so unfortunately I have to go with a mix if I want to add more panels. I did speak to AM Solar about this and they said the panel I have in mind, another AM Solar panel, would be compatible with my system.

We do a lot of boondocking in tree-shaded sites and the weather can be overcast a lot of the time. Our AGMs with 100 AH (useable) typically lasts us 4-5 days under these conditions. That was our thought process with moving to 400 AH usable. We want to be able to last 10+ days under less than ideal solar conditions and not have to worry about it. That to me is worth the $4K investment.

[uncle_bob]

Originally Posted by Meddle

Hi AirMiles, we hardly have a need for the inverter, in fact I think we've powered it up maybe twice in 6 years. It came with the trailer, but everything we run is 12V. I figure I'd keep it and wire it in just in case the occasional need does come up.

I have two 135W AM Solar PVs already, but AM Solar isn't making that panel anymore, so unfortunately I have to go with a mix if I want to add more panels. I did speak to AM Solar about this and they said the panel I have in mind, another AM Solar panel, would be compatible with my system.

We do a lot of boondocking in tree-shaded sites and the weather can be overcast a lot of the time. Our AGMs with 100 AH (useable) typically lasts us 4-5 days under these conditions. That was our thought process with moving to 400 AH usable. We want to be able to last 10+ days under less than ideal solar conditions and not have to worry about it. That to me is worth the $4K investment.

Hi

Pretty much exactly the same though process that got me to go from two AGM's to four lithium's. With a modern Classic, I could not go 4 days on the AGM's in the shade, but otherwise same sort of numbers. So far I'm quite happy with the choice I made. We'll add a third solar panel to the roof soon. I'm not counting on that for a lot most of the time. We like the shade .....

Bob

[czunc]

I have a quick question about attaching the AM Solar feet.



We finally have a warm dry weekend ahead of us so I want to finish my install. All I have left is to stick my 4 panels to the roof but I,m not sure how long I need to let the VHB tape cure before covering with sealant. My plan is to clean the roof in the morning, wait until after lunch to install the feet and maybe seal them on Monday night?? We are leaving for Big Bend on Weds. night so I want everything to be cured before leaving on a 9 hour drive.

[lewster]

You don't really have to wait for sealing the panels. I use SikaFlex 221 for that purpose......in grey. After you set and seal the panels, they are really stuck down, but require 2-3 days to start curing, and a full 30 days for the tape to fully set.

Careful application of the sealant will allow use of the trailer in the 2-3 day window.

[czunc]

Thanks Lewster! I plan to clean with carb cleaner 1st then stick the foot in place. I did go with the 221 but in white to match my roof. I've read where alcohol will effect the 221.

[lewster]

Sounds like a plan!!!!

[AirMiles]

This past weekend I was dry camping in Punta Gorda Florida on a rainy and overcast day. Occasionally, the sun would pop out of the overcast for a moment. During one sunny moment my 400W solar array, using the factory 10 gauge prewire, peaked at 434 Watts of production. This is a new record level for my system. Attached is a screen shot documenting this production.

I believe there were two reasons for exceeding my 400W panel rating. First, when the sun is at the edge of a cloud it intensifies in the same way as a magnifying glass increases the sun. Second, and similarly, the same magnifying affect occurs when water droplets sit on the panels. I believe much of the dramatic increase in power was due to this magnifying effect. Also, due to the overcast conditions for most of the day, my Victron 100/30 controller was still in bulk mode at 1 pm when the sun was at its peak. Typically, bulk mode is done before peak sun so the Victron controller starts reducing amperage, an therefore solar wattage, to hold the voltage at its absorption level setting.

Even though the rainy and overcast conditions continued for the rest of the day, the system completely charged my batteries by obtaining float stage at 3:45 pm. The 400W array produced 830 Watt Hours to obtain float status. At a 13.5V average output, this would total 61.5AH of charging (830WH/13.5V=61.5AH). I'm satisfied with getting 60+ Amp Hours of battery charging on a rainy and overcast day.

[gregwall]

Originally Posted by AirMiles

This past weekend I was dry camping in Punta Gorda Florida on a rainy and overcast day. Occasionally, the sun would pop out of the overcast for a moment. During one sunny moment my 400W solar array, using the factory 10 gauge prewire, peaked at 434 Watts of production. This is a new record level for my system. Attached is a screen shot documenting this production.

I believe there were two reasons for exceeding my 400W panel rating. First, when the sun is at the edge of a cloud it intensifies in the same way as a magnifying glass increases the sun. Second, and similarly, the same magnifying affect occurs when water droplets sit on the panels. I believe much of the dramatic increase in power was due to this magnifying effect. Also, due to the overcast conditions for most of the day, my Victron 100/30 controller was still in bulk mode at 1 pm when the sun was at its peak. Typically, bulk mode is done before peak sun so the Victron controller starts reducing amperage, an therefore solar wattage, to hold the voltage at its absorption level setting.

Even though the rainy and overcast conditions continued for the rest of the day, the system completely charged my batteries by obtaining float stage at 3:45 pm. The 400W array produced 830 Watt Hours to obtain float status. At a 13.5V average output, this would total 61.5AH of charging (830WH/13.5V=61.5AH). I'm satisfied with getting 60+ Amp Hours of battery charging on a rainy and overcast day.

Those are very impressive numbers. Love the explanation and seeing the history panel. Can't wait to get on the road.

Hello Lewster! Hope all is well in Florida!