Factory Installed Solar Charging System

[Poppy545]

I have been having problems with my solar system. The voltage was never higher than 11.8 VDC since I bought it two months ago. The installers at the AS factory install my SUNEXPLORE II 40Amp Controller according to the instructions that came with the kit. This little blue wire lets the controller know that AGM batteries are installed and for the controller not to enter the equalization phase. This phase gives it 15.8 VDC which AGM batteries hate. They are sensitive to overcharging and I think that is why my batteries are so weak. You can not get a lot of service out of these batteries if the boys at the factory don't follow the instructions. They told me that since my Globetrotter is considered used, they aren't responsible. Only two years old! Phewy!

[AirstreamJim]

We just traded up to a 2009 Classic 34 that has the factory solar system installed (two 53-watt panels with the original SunExplorer controller). Since the original Lifeline batteries built in 2008 are still in the trailer and are about to be replaced (they're in a sad state...), I'd like to upgrade the solar controller and the factory converter to get better bang from my solar panels, and treat the new Lifelines a little better than the old ones.

I'm not looking to (a) spend a lot of money or (b) re-wire the entire system. With that said, is there a simple solution that I can throw at the trailer that will utilize the existing wiring, including the RJ45 connection to the SunExplorer display in the galley? I've read about the Renogy Commander, but that was in reference to an Interstate installation, and it appears the Commander isn't a current product anymore. I'm not absolutely opposed to doing some minor rewiring, but anything that requires fishing through walls is beyond my ability and interest level....

As to the converter - I assume the PD4655 would be a good choice? I put that in our previous AS and I was happy with the results. Does having solar affect anything with regards to the converter?

Any advice for this solar novice is appreciated.

Jim

[Flyfisher36]

Have a 2019 International 28RB and planning a solar and inverter install.. Has anyone tried pulling the 10 guage wires installed to enable you to fish a larger gauge through the same routing path? OR is the pre-wired secured behind the aluminum skin...

[uncle_bob]

Originally Posted by Flyfisher36

Have a 2019 International 28RB and planning a solar and inverter install.. Has anyone tried pulling the 10 guage wires installed to enable you to fish a larger gauge through the same routing path? OR is the pre-wired secured behind the aluminum skin...

Hi

I've tried that on various wires in the AS. The gotcha is that they tend to hang up as you pull them.

There really is no need to replace the wires. They are adequate for any number of panels you might put up there. You simply have to think about what you are doing. Past a certain point series / parallel ( or higher voltage panels ) would be the way to go.

The math:

A typical RV "12V" panel puts out max power at about 20V. 100 W at 20V is 5A. Your wire is rated for 40A ( it's high temp insulation, fused at 40A from the factory). You *could* indeed put 8 panels in parallel. (could is different than should ....).

A better approach would be to put them in series a pair at a time. You then have 40V coming down the wire and 20A of current. You also could go to "24V" panels and keep them all in parallel. The result would still be 20A of current max. If you go to the higher voltage, you will need a controller (like a Victron) that will handle that voltage.

Can you get 8 panels on top of a 28'? That's going to be a pretty tight install. Four is doing pretty well. Six would be my guess as a max.

Bob

[Flyfisher36]

Thanks Bob very informative giving more options to consider..

[Rocinante]

I would agree with Bob on the panel count. On the 28FB we used to own,we managed to squeeze in 6 of the smaller / denser / more expensive 100-watt panels and one 50 watt panel for a total of 650 watts. We had 400Ah of LiFePO4 batteries under the bed, and this array / battery combination worked beautifully for us. We pretty much felt like we had unlimited power as long as we didn't try to run the air conditioner. Our system would do that too for a few hours, but if the climate became hot enough to really need AC throughout the day, it was time to either move to cooler climes or find a place where we could plug into 30 amps.

[lewster]

Depending on the number of panels you will wind up with, I would NOT USE the 10AWG cable that Airstream included with your trailer. Sure, 10AWG has a stated capacity of 30 amps but for solar, you will be losing easily 10-20% of your charging amperage with using the 10AWG.

The smallest cable I use is 6AWG, and that goes to 4AWG over 400 watts of solar, and 2AWG over 800 watts. The 2AWG the goes to multiple strands of 2AWG over 1400 watts (for the big rigs) that are set up in parallel. Series connections can use smaller cable, but there can be other problems with series-connected smaller panel configurations.

Get in touch with me if you would like to know where the larger wire is pulled from and where it generally ends up.

[uncle_bob]

Originally Posted by lewster

Depending on the number of panels you will wind up with, I would NOT USE the 10AWG cable that Airstream included with your trailer. Sure, 10AWG has a stated capacity of 30 amps but for solar, you will be losing easily 10-20% of your charging amperage with using the 10AWG.

The smallest cable I use is 6AWG, and that goes to 4AWG over 400 watts of solar, and 2AWG over 800 watts. The 2AWG the goes to multiple strands of 2AWG over 1400 watts (for the big rigs) that are set up in parallel. Series connections can use smaller cable, but there can be other problems with series-connected smaller panel configurations.

Get in touch with me if you would like to know where the larger wire is pulled from and where it generally ends up.

Hi

Here's the math:

10 AWG is right at 1 mili ohm per foot ( makes the math easier)

You have two wires involved so that goes to 2 mili ohms per foot traveled

The run on most of these trailers is ~ 20 feet.

That would get you to 40 mili ohms

30 A at 40 mili ohms is a 1.2 V drop.

The only way that gets you to 10% is if it's on the output side of the solar controller.

If you go to 30', then you are up to a 1.8V drop at 30A. That would get you 10% at a cell peak power point of 18V. At lest for the cells on my roof, that's a bit lower than where they normally do max output.

As output drops, so does current. With a solar cell, current (at the max power point) drops faster than voltage. Your worst case efficiency "hit" from the wire is at peak power. Most of the time you are at less than peak power, so most of the time, your percentage loss is less.

All that said, series connection is still the better answer to the question. Double the voltage and halve the current. Your 10% is now 2.5%. Yes, you *do* need a good controller to make that work.

Bob

[jeffmc306]

Originally Posted by AirstreamJim

We just traded up to a 2009 Classic 34 that has the factory solar system installed (two 53-watt panels with the original SunExplorer controller). Since the original Lifeline batteries built in 2008 are still in the trailer and are about to be replaced (they're in a sad state...), I'd like to upgrade the solar controller and the factory converter to get better bang from my solar panels, and treat the new Lifelines a little better than the old ones.

I'm not looking to (a) spend a lot of money or (b) re-wire the entire system. With that said, is there a simple solution that I can throw at the trailer that will utilize the existing wiring, including the RJ45 connection to the SunExplorer display in the galley? I've read about the Renogy Commander, but that was in reference to an Interstate installation, and it appears the Commander isn't a current product anymore. I'm not absolutely opposed to doing some minor rewiring, but anything that requires fishing through walls is beyond my ability and interest level....

As to the converter - I assume the PD4655 would be a good choice? I put that in our previous AS and I was happy with the results. Does having solar affect anything with regards to the converter?

Any advice for this solar novice is appreciated.

Jim

Jim, I just replaced our factory Atkinson with a Victron 100/30 and reused the RJ45 connector cable to a Victron BVM-712 battery monitor where the old Atkinson was mounted.

Like you, I didn’t want to rewire but do have the 8 ga. factory solar wire. I followed AM Solar’s diagram for the location of a 40A breaker and disconnect switch. I found some 18” and 24” battery cables for lawn tractor starter motors to connect everything together.

The Victron display uses an RJ12 connector so needed a way to adapt to the male RJ45. I cut one end of the Victron RJ12 cable 6” from the end to make a pigtail and terminated the three pairs to an RJ45 female jack. I used another RJ45 jack at the old solar controller side then connected the RJ45 cable at both ends.

I made a walnut wall plate the same size as the old Atkinson display and mounted the Victron BVM-712 which matches our Globetrotter’s trim.

It’s so nice to be able to see historical data from the Solar Controller from the App.

Good luck with your upgrade!
Jeff

[1023Steve]

This is my first AS and my first camper... 29' Excella 1993.

When I bought it, I was on information overload...The seller was very thorough. He explained everything.. however, I was more worried about making it 600 miles home instead of the solar. I also thought these panels were factory installed and could find info on them when I needed it. I don't think the panels are factory installed because there is nothing in the owners manual(?).

So here I am... a year later... and will be boondocking for a music festival and need to figure it out.

This is what I remember...The seller told me to connect these orange wires when using solar. There is a fuse at the connection point. I have circled it in red in the photo. When I attached them the orange box lit up.

Also, none of my outlets work when I'm running on battery. Only lights and radio. I haven't checked the water pump.

any help or any information is VERY APPREACETED!

[n2916s]

It looks like a very basic setup to recharge your 12 Volt battery(ies). You might connect it, get the orange box lit up and then put a volt meter across the terminals on your battery and see what voltage you get. It should be greater than 13 when the sun is shining.

If it is. You are in business for getting some charge back in your batteries while boondocking. This will keep your refrigerator running (it requires 12v power even when on propane), power your lights, water pump, furnace blower. In moderation, you have no idea what size the roof panels are or how efficient!

As for the outlets — those are 120 Volt AC outlets like you have at home. You won’t find power there unless you are plugged in to your home or at a campground or with a generator.

Theoretically, you could have an inverter somewhere. This is a device that takes 12 volt power from your batteries/solar and produces AC power. Not common in 1993, more so now.

[1023Steve]

Originally Posted by n2916s

It looks like a very basic setup to recharge your 12 Volt battery(ies). You might connect it, get the orange box lit up and then put a volt meter across the terminals on your battery and see what voltage you get. It should be greater than 13 when the sun is shining.

If it is. You are in business for getting some charge back in your batteries while boondocking. This will keep your refrigerator running (it requires 12v power even when on propane), power your lights, water pump, furnace blower. In moderation, you have no idea what size the roof panels are or how efficient!

As for the outlets — those are 120 Volt AC outlets like you have at home. You won’t find power there unless you are plugged in to your home or at a campground or with a generator.

Theoretically, you could have an inverter somewhere. This is a device that takes 12 volt power from your batteries/solar and produces AC power. Not common in 1993, more so now.

Thank you! That explains a lot. I kept reading about folks plugging into 110 when running on solar panels. Hopefully I can keep those two batteries charged. We won’t need heat, so it looks like the fridge, lights, and water pump. I didn’t know the fridge needed power. Hopefully not much... If I had to guess the 2 panels are 2’x4’. I will test the voltage like you recommend. Kind of bummed I can’t charge a phone though. Anyways.. really appreciate the response.

[n2916s]

Should be able to charge a phone using a “cigarette lighter” style of charging cord. There should be at least one socket — look next to the TV panel. maybe even one in the bathroom.

[uncle_bob]

Originally Posted by 1023Steve

This is my first AS and my first camper... 29' Excella 1993.

When I bought it, I was on information overload...The seller was very thorough. He explained everything.. however, I was more worried about making it 600 miles home instead of the solar. I also thought these panels were factory installed and could find info on them when I needed it. I don't think the panels are factory installed because there is nothing in the owners manual(?).

So here I am... a year later... and will be boondocking for a music festival and need to figure it out.

This is what I remember...The seller told me to connect these orange wires when using solar. There is a fuse at the connection point. I have circled it in red in the photo. When I attached them the orange box lit up.

Also, none of my outlets work when I'm running on battery. Only lights and radio. I haven't checked the water pump.

any help or any information is VERY APPREACETED!

Hi

This is very much a "that depends" sort of thing.

Solar has come a *long* way since 1993. What was a high end / very expensive install 10 years ago is pretty basic today. The further back you go, the more basic things become.

You *could* have 60W of solar on the roof. That's fine for keeping the batteries toped off in storage. It's not going to do much good past that. You could have 120W "original" capacity on the roof. After many years up there, it now could be delivering < 60W. Lots of possibilities.

What is pretty obvious looking at the pictures is: that's not a "pro" install. At least it's not up to modern pro standards. I would spend some quality time tracing things out and figuring out just what's what. I'd also do a bit of testing to see how well it all works.

Best guess: you have a lot of the crazy work done (wire are all run ...) for a solar upgrade. Without that upgrade, not a lot of functionality ....

Bob

[1023Steve]

Appreciate the response uncle_bob, although hoping you're wrong about just being able to top the batteries off. It does makes sense now that you say it.

Since I'm not real confident in my ability to start testing everything and diagnosing watts from old panels, I might just try to drain the batteries down by using the lights, fans, radio, etc.. and see how fast my batteries recharge the next day with them all off and a sunny forecast.

If anybody is curious, I will snap a picture of the panels this weekend.

[uncle_bob]

Originally Posted by 1023Steve

Appreciate the response uncle_bob, although hoping you're wrong about just being able to top the batteries off. It does makes sense now that you say it.

Since I'm not real confident in my ability to start testing everything and diagnosing watts from old panels, I might just try to drain the batteries down by using the lights, fans, radio, etc.. and see how fast my batteries recharge the next day with them all off and a sunny forecast.

If anybody is curious, I will snap a picture of the panels this weekend.

Hi

Without a way to measure current in and out of the battery, working out what's what on a system like this is going to be tough.

Bob

[AirstreamJim]

Following up on this...I saw on a certain Facebook Airstream group that Atkinson has released a new solar controller that is a drop-in replacement for the controller in our Airstreams. Apparently it has appropriate charging regimens for the various different battery technologies (including Lithium). The web page for the device is at http://atkinsonelectronics.com/pvcm4...oint-tracking/.

Does anyone know anything about this? Given my desire to upgrade my solar configuration without having to rewire everything, if Atkinson’s claims are true, it seems this would be a very economical and easy upgrade for someone who isn’t hell-bent to have the best solar generation system in the RV world; I just want my batteries to recharge on those rare occasions when we’re not at a full hookup campground.

Thoughts?

Jim

Originally Posted by AirstreamJim

We just traded up to a 2009 Classic 34 that has the factory solar system installed (two 53-watt panels with the original SunExplorer controller). Since the original Lifeline batteries built in 2008 are still in the trailer and are about to be replaced (they're in a sad state...), I'd like to upgrade the solar controller and the factory converter to get better bang from my solar panels, and treat the new Lifelines a little better than the old ones.

I'm not looking to (a) spend a lot of money or (b) re-wire the entire system. With that said, is there a simple solution that I can throw at the trailer that will utilize the existing wiring, including the RJ45 connection to the SunExplorer display in the galley? I've read about the Renogy Commander, but that was in reference to an Interstate installation, and it appears the Commander isn't a current product anymore. I'm not absolutely opposed to doing some minor rewiring, but anything that requires fishing through walls is beyond my ability and interest level....

As to the converter - I assume the PD4655 would be a good choice? I put that in our previous AS and I was happy with the results. Does having solar affect anything with regards to the converter?

Any advice for this solar novice is appreciated.

Jim

[Samrh]

Hey Jim. I did that exact upgrade to my 2018 FC. I removed the factory batteries and replaced them with two drop in BB Lithiums in the box up front. Replaced the solar charge controller you mentioned after talking with the friendly people over at Atkinson. Then I needed to upgrade the converter under the fridge because lithiums can charge at a higher rate. (crazy spot to get at BY THE WAY) The Atkinson upgrade was plug and play and everything works fine. Although for some reason my display ALWAYS says 100% charge even after two days offgrid using 80/90 amp hours of my 200 amp bank. I know this because I could not resist getting a Victron 712 battery monitor for the bluetooth. I just left it under the bed with the rest of the gear and use the bluetooth for the readings.
The only other issue is that an MPPT solar charge controller, from what I understand, would do a more efficient job of charging the lithium batteries. At this time with 2 batteries and 400 watts of solar, for the offgrid we do now, we are just fine. Twice I had to break out my Renogy portable panel to get a boost when the roof top can not catch up after a cloudy day here in Florida. Which doesnt happen often. Have Fun out there !!!

[todd s]

I have a 2018 International with the factory installed option Solar Panels for a 25FB, two panels. How many total watts do those panels produce? What is the battery management system used? Can't find the info. thanks

[uncle_bob]

Originally Posted by todd s

I have a 2018 International with the factory installed option Solar Panels for a 25FB, two panels. How many total watts do those panels produce? What is the battery management system used? Can't find the info. thanks

Hi

This is Airstream so never say "always" ....

They typically used 90 or 100W panels on the 2018's. Supplier? Who knows. Zamp is often mentioned. I'm not sure this is correct.

The typical solar controller was an Attwood. Easy way to tell: Do you have a monochrome LCD panel that shows solar information? They mount in a very normal outlet box built into the wall. If so, you have an Attwood. Scrap it.

At some point in the 2018 => 2019 transition they did go to Victron MPPT's. Did that happen right at the year break? Easy way to tell: With the Victron MPPT you get a circular readout that says "Victron" on it.

Bob