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Old 08-25-2017, 12:12 AM   #1
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Can you run your AC off your batteries with a Roadtrek Solar system and for how long before the engine generator comes on.

How reliable is the under hood engine generator with that long belt and unit hung under the frame? Thanks for your answers.
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Old 08-25-2017, 12:19 AM   #2
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Can you run your AC off your batteries with a Roadtrek Solar system and for how long before the engine generator comes on.

....


How much solar do you have? How many watts?

Do you know the wattage of the AC?


I guess you got my drift.
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Old 08-25-2017, 12:22 AM   #3
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have not bought a van yet hence I ask the question here. Any input is much appreciated.
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Old 08-25-2017, 12:52 AM   #4
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have not bought a van yet hence I ask the question here. Any input is much appreciated.

You can check the spec to see how much solar they have.
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Old 08-25-2017, 12:56 AM   #5
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.

Nothing really runs off the solar...

You use the solar to charge the batteries,
which in turn provides power to the appliances.

A typical AC is 1,200~1,800 watts.

If you want to run the AC off-line,
you will need a large battery bank.
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Old 08-25-2017, 01:06 AM   #6
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From what we have heard from other users, you can't get enough solar on the roof of a B to have a significant effect on AC run time.

What we have heard is that 800ah of batteries will run 4-5 hours before the engine generator is needed, but then there can be an issue with being able for the engine generator to keep up with running the AC and charge the batteries at the same time, especially at idle speeds. It is commonly called the "death spiral", and you wind up out of battery capacity and engine generator cycles, so no AC.

There are lots of discussions on this forum about this issue, and if you are looking to be able to reliably run AC off of the batteries and engine generator, it would be good for you to look at all of them. It is not a cut and dried conclusion, by any stretch of the imagination.
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Old 08-25-2017, 04:50 AM   #7
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Quote:
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.
Nothing really runs off the solar...
You use the solar to charge the batteries,
which in turn provides power to the appliances.
/squinting

I don't think that is a supportable position.

Experiments:
  1. attach loads direct to panels; see if loads run off solar
  2. Assume battery at 100% SoC. Run CC output, battery, and loads to the same bus. Does power come from the CC, hit the bus, run down to the battery pos terminal, back up the same wire back to the bus and out to the load? If so, why?
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Old 08-25-2017, 10:52 AM   #8
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Quote:
Originally Posted by fratermus View Post
/squinting

I don't think that is a supportable position.

Experiments:
  1. attach loads direct to panels; see if loads run off solar
  2. Assume battery at 100% SoC. Run CC output, battery, and loads to the same bus. Does power come from the CC, hit the bus, run down to the battery pos terminal, back up the same wire back to the bus and out to the load? If so, why?

You write well,
but you should work on your comprehension.

I did not say you CANNOT run off solar.
You can attach a LED light to to the panel. It would work, during the day.

I asked how much solar...
If you have enough panels (not likely in a ClassB) you can run your AC directly during midday sun.
But is it practical? Can you run your AC this way on a hot humid night?

Oh yea you can attach directly to solar,
but nothing really runs off solar,
You use the solar to charge the batteries,
which in turn provides power to the appliances.

A typical AC is 1,200~1,800 watts.

If you want to run the AC off-line,
you will need a large battery bank.
Whether the electron is coming from the wire or the post
is academic. And I don't think you have a PhD on the subject.
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Old 08-25-2017, 01:01 PM   #9
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Best just to say the solar maybe can generate enough power to run whatever it is, some of the time. The rest is academic at that point.

Most people just look at power harvesting during the day by checking the solar controller, if it has that data. Power generated by the solar at the same time as power is being used is substantially more efficient as it doesn't have the charge and discharge efficiency losses.

Nearly every solar controller needs to have a battery in the circuit so that the controller can regulate the voltage properly. How big to make the battery is totally open as long as it is big enough to accept the full solar output continuously or the controller is temperature compensated.
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Old 08-25-2017, 01:16 PM   #10
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you could look at underfloor AC. it is run on DC and uses less power.
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