Factory solar

[jlandreth]

So, here's another question about a 30' Classic that we won't get until next month. As you all know, the 2019 Classics come stand with the 240 watt solar system. Question is this, should I have additional panels installed by the dealer before I pick it up? Hopefully the wife and I will be doing some boondocking next spring and I was wondering if the factory solar could benefit from additional panels or would I be wasting money.

[kendrick.l.j]

it all depends on your style of camping. If you plan to boondock you’ll need to upgrade the entire system, not just add panels. If you plan to use full hookup option then you’ll be fine. You’ll still need to upgrade to better battery and inverter. I use my solar as emergency backup and can go 3 days on solar alone (obviously being ultra conservative with energy usage). If you plan on boondocking might do better by buying a generator instead of trying to make things work on solar. There is a member here named Lewstar (sp) that works magic on installing solar system, might need to ask him.

[billrector]

Originally Posted by jlandreth

So, here's another question about a 30' Classic that we won't get until next month. As you all know, the 2019 Classics come stand with the 240 watt solar system. Question is this, should I have additional panels installed by the dealer before I pick it up? Hopefully the wife and I will be doing some boondocking next spring and I was wondering if the factory solar could benefit from additional panels or would I be wasting money.

My recommendation would be to wait and see how your 240W performs before having a solar upgrade. I would also add that you can likely do a much better system at an independent shop specializing in solar installations.

There is also some merit to having a portable solar panel. The advantage is that these can almost always be pointed to the sun, unlike panels fastened to your roof. You can get an additional 200W panel from someone like Renogy for a reasonable amount of money. The disadvantage is you will need to set them up each time and there is a risk of theft.

[blkmagikca]

It also depends on what gauge of wiring is used at the factory. 10AWG may be OK for 200-watts of solar, but you will need a minimum of 8AWG for 400 watts. In fact, upgrading the wire is mostly a labor cost - I opted to spend an additional $50 and had mone upgraded to 6AWG. Then when I added more solar (now 540 watts), the wiring was sufficient.

[uncle_bob]

Hi

Solar only works when ...errr ... the sun shines The gotcha is that to do well, it needs a *lot* of sunshine. We happen to live in the east and the sort of campsites we wind up in are typically nice and shady (at least the ones we like are). That shade can easily knock your "daily solar" down to 10% or less of the best case total.

In a Classic, running the heat (it is late fall ...) you have the combo of power drain and cloudy / rainy sky. Even out of the shade, there may not be a lot of solar coming in compared to what you are using.

As mentioned above part of the answer is bigger batteries. Your stock battery setup provides about 100AH of usable capacity. That may keep you going for a day, it may be enough for two days with some care. Turn on the inverter and the "maybe one day" is optimistic.

For us, the most rational (as if any of this is rational !!) decision was to bump the batteries up to 400AH of usable capacity. That plus the (2017) stock solar panels has done quite well for us.

Even on a Classic, there is a very limited amount of space. Before you decide to give up some of that precious space for this or that, get out and use the beast. See how it works for you and what sort of places you like to go. See how camping without AC works for you ( = the size of solar to run AC full time is massive). You may camp mostly at places with shore power in the June - September time frame. Who knows ....

Bob

[ROBERT CROSS]

Use it for a Season and decide...Sol will still be there next year. 😎
You may be surprised and find some other up-grades that you really do NEED. 😂

Bob
🇺🇸

We got this after 11yrs...😉

[jlandreth]

Thanks for the input. As usual I am getting ahead of myself here. Using it for a while and then determining what will work for us makes since. While reading a thread on the solar forum, it appeared to me that you can't use a portable panel hooked to the zamp connector at the batteries while you have the roof top panels. I would love to get a suitcase panel to use when we are parked in the shade but I think you have to do some modifications to us e both.

[ROBERT CROSS]

I'm not sure how the suitcase would work when plugged into the 'factory' Zamp receptacle on your AS.
I use the 7pin umbilical which goes directly to the batteries, I don't see that the factory Zamp connector would be wired any differently.
Others are going thru the same process and I believe they are not using the controller that is supplied with the portable units. A bit problematic if you ever want to use it as a standalone. Re-wiring the portable controller to be taken in and out of the loop is the most obvious work-around.

Bob
🇺🇸

[uncle_bob]

Hi

The "factory Zamp connector" is just a pair of (fused) wires going from a dirt cheap connector to the battery posts. That's all it is. A pair of clip leads on the battery posts would do the same thing. Running in through the 7 pin does the same thing.

What you would *like* to have happen with a portable panel is for it's power to add in with the power from the other panels. If the battery is completely dead, yes that works. Once you get past the first bit of charging, the controllers start to fight with each other. Unless they are very unusual controllers ( or they can talk to each other) one will win the fight and supply all the power.

Bob

[ROBERT CROSS]

'splain please.."one will win the fight and supply all the power."

How does one win?

If I get a second panel,(may be in the works), and it's connected directly to the battery, how would one controller be rendered useless when charging.
If the purchase does happen I would like to be able to use both separately w/o modifying the wiring for each.

Bob
🇺🇸

[jlandreth]

So if I am understanding this correctly, I could add a portable panel connected by alligator clips directly to the battery and it will not interfere with the factory system?

[gator.bigfoot]

Originally Posted by jlandreth

So if I am understanding this correctly, I could add a portable panel connected by alligator clips directly to the battery and it will not interfere with the factory system?

If you do that make sure you have blocking diodes installed. Personally I wouldn't do it. Connect the portable panel in parallel to the factory solar. Most likely the factory solar wires are coming down through the fridge area. You can tap into them there. If not I would make the effort to find out where and run a set of quick connections out of a storage compartment or something similar. If all else fails you can pick up a cheap pwm controller like the Prostar from MorningStar. Then it's truly stand alone.

[jlandreth]

Understood, thanks for the input.

[ROBERT CROSS]

Originally Posted by jlandreth

So if I am understanding this correctly, I could add a portable panel connected by alligator clips directly to the battery and it will not interfere with the factory system?

Zamp portable?...our unit has a connection line from the Zamp controller with alligator clamps...that was the reason for my question above. I don't see how separate controllers interfere with each other.

Bob
🇺🇸

[68 Overlander]

By far the two most popular upgrades to a new unit is the Zamp portable suitcase and 4 stage converter. The 160 watt Zamp is the most popular because of weight and storage size and the Progressive Dynamics Wildkat 4655L for the 30 amp service 8955 converters and Boondocker 1260CL for the 50 amp service deck mounts. All are capable of charging and maintaining Lithium if you go that route in the future.

[68 Overlander]

Originally Posted by jlandreth

So, here's another question about a 30' Classic that we won't get until next month. As you all know, the 2019 Classics come stand with the 240 watt solar system. Question is this, should I have additional panels installed by the dealer before I pick it up? Hopefully the wife and I will be doing some boondocking next spring and I was wondering if the factory solar could benefit from additional panels or would I be wasting money.

I have never heard anybody say I bought too much engine or solar. Some try and justify what they have, me included but there is no replacement for displacement still rings true.

[gator.bigfoot]

Originally Posted by ROBERT CROSS

'splain please.."one will win the fight and supply all the power."

How does one win?

If I get a second panel,(may be in the works), and it's connected directly to the battery, how would one controller be rendered useless when charging.
If the purchase does happen I would like to be able to use both separately w/o modifying the wiring for each.

Bob
🇺🇸

Ideally your chargers are the same, but if they are set to the same charge profile they will work in conjunction. What can happen when they are not set the same is that one charger will sense that it already has achieved max and turn itself off. Please see https://www.morningstarcorp.com/para...ate-pv-arrays/ it has an excellent write up on this.

[stevejones]

Originally Posted by ROBERT CROSS

Zamp portable?...our unit has a connection line from the Zamp controller with alligator clamps...that was the reason for my question above. I don't see how separate controllers interfere with each other.

Bob
����

On my 2019 Globetrotter it is as Uncle Bob reports. On the tongue is a Zamp plug for connecting a portable panel. This connector goes straight to the batteries in the battery box. It does not go to the factory installed controller.

So I guess it is important to determine for your model, how your connector is hooked up since there seems to be some variation.

I my case, if I were to add a portable panel, it would be supplying voltage directly to the battery. Because of this the controller for my factory installed panels will see a voltage that is a combination of what the batteries are charged to and what is coming from the portable panel. If this is in excess of 12.7V it would shut down any power from the roof top panels going to the battery. The opposite could also happen if the roof top panels are charging the battery and I plug in the portable. The controller on the portable panel would shut down if it sees a voltage higher than it's threshold. Depending on which set of panels is already charging the batteries the other set may not operate because of their controller. I think this is what Uncle Bob is talking about.

Steve

[Silvr_Bullet]

I have been in this conversation before, sorry to say your answers will likely be ‘opaque’ and I found them to be inconclusive. I have factory installed roof top Zamp and Zamp portables configured with Zamp plug connected as yours, it works. It would be nice if someone from Zamp or Airstream would jump in here. I hope you get an answer that your comfortable with. Congratulations on your Airstream.

[uncle_bob]

Hi

Ok, let's go down the list:

Blocking diodes for a portable - not so much. The portable has a converter in it, there is no benefit from blocking diodes. All a blocking diode does is take care of current going the wrong way. A converter is already built so this does not happen. One example: your converter charger does not need a blocking diode when you are off shore power ....

Battery voltages: If your battery is charged up, its voltage is higher than if it's not charged up. The charger goes into a sequence of voltages to attempt to get a battery charged without doing anything nasty. The key points here are that it will drop back to ~13.2V to float the battery once the current goes down.

So what happens:

Charger one (say it's the portable) comes up and starts putting out > 13.2V to charge up the batteries, it's supplying a bunch of current and stays up at a nice high voltage (let's call it 13.643V) to get the job done.

Charger two (say it's on the roof) comes up and also tries to do the same thing. It puts out 13.579V. Since its voltage is lower, not so much current comes out. It sees the low current and drops back to float mode. Since that is 13.2V ... no current at all. (yes there may be a bit of a time delay).

Now, if the "winner" is the portable panel, this works until somebody walks in front of the panel. Then the output drops and the second unit (roof) gets back in the act. As soon as the panel is back in the sun, they try to work it out again. Since the output voltages are temperature dependent, who knows which one wins this time.

Ummm.... what ... errr ??? Temperature dependent? Yes, the stock solar charger in your AS is temperature compensated. Its output voltage changes with temperature to track the "right" voltage to charge a battery at. It's not the only solar charger out there that does that.

The real root cause to all this - they never were designed to work together. The assumption when they were designed is that each one would be the *only* device trying to charge the battery. In most cases that's a pretty good bet. Since there *are* devices out there designed to work together, the assumption is that you would spend the money to buy one of them if that's what you needed.

Bob