Starting here, Saying Hello!

[Gamekeeper]

Hello, my name is Greg.

I am a beginner solar aficionado.

I have really enjoyed Will’s channel on YouTube, as well as reading on this site, for a long time.

I am embarking on Understanding and installing solar charging systems on two cabins, and a travel trailer. With the travel trailer taking priority, because we will be heading to Arizona for a portion of the winter after Christmas.

I have been accumulating a pile of parts and pieces, connectors, wires etc., and will be very carefully constructing a very safe and very effective solar powered battery charging system.

I will be asking questions in the various sub forums, and welcome everyone’s input and support.

Sincerely,

GregT

 

[iamrich]

Welcome! How big is the travel trailer and what in it are you trying to power?

 

[Gamekeeper]

Welcome! How big is the travel trailer and what in it are you trying to power?

Winnebago 2108TB
It’s not huge, it’s Winnebago’s take on a rough service trailer.

My power needs are primarily to keep things from freezing.
As far as solar goes, the technical complication is I live in the Great Lakes region where it is forested, and mostly cloudy, most of the time.

I believe, and I’m sure this will be sorted out more precisely in the build thread over in the RV section, that I am going to end up with 4 to 600 amp hours of lithium, and then a set of solar panels and and charging system that allows for enormous charge rates on the days when the sun does shine.

But that’s just a guess at the moment.

 

[iamrich]

How much space do you have on the roof. I looked up the model (pretty cool by the way), but apparently no one has ever taken a picture of the roof I see at least two objects (AC? and a vent) that will be in the way, but I would squeeze as many panels as you can onto that roof.

 

[Gamekeeper]

How much space do you have on the roof. I looked up the model (pretty cool by the way), but apparently no one has ever taken a picture of the roof I see at least two objects (AC? and a vent) that will be in the way, but I would squeeze as many panels as you can onto that roof.

There is a proximately 9 feet 6“ x 30“ available on either side of center, lengthwise.

And then, at the rear, there is a space between the bathroom skylight, and the television antennas, that can have two additional panels of similar size.

That’s why I purchased 10 panels, eight for this project, And two spares.

I am away from the trailer at the moment, so I can’t be more precise.

I forgot to bring with me my energy audit, otherwise I would’ve posted all of the data for this install in my other thread.

This can be a pretty tough crowd here.

edited to add:

I have been stuck out in the woods with depleted batteries, and no ability to charge them.

As a mobile install, having an alternative that is always with you, and always works, (no matter the weather or the location), is very important to me.

I think some of the folks that are perhaps less mobile underestimate the predicament and the point of a dc-dc mppt controller.
For short money, you can get the slide pulled in, or the furnace running, without regard for time of day, or the weather. No small thing.

 

[iamrich]

800w of panels with limited sun is going to limit your solar options. You can probably expect 2kw on a good day in winter, so that is what you have to play with. Maybe a simple charge controller feeding a drop-in replacement LiFePo for now.

100ah 12v LiFePo $350ish?
EPEVER 60A MPPT Solar Charge Controller $250
Wiring and stuff $100

This will give you 1000w to play with I would think, assuming you get 2 hours of sun a day. Otherwise, you are going to have to rely on the generator.

 

[RickP]

Welcome to the forum, and best wishes on your projects!

 

[Gamekeeper]

800w of panels with limited sun is going to limit your solar options. You can probably expect 2kw on a good day in winter, so that is what you have to play with. Maybe a simple charge controller feeding a drop-in replacement LiFePo for now.

100ah 12v LiFePo $350ish?
EPEVER 60A MPPT Solar Charge Controller $250
Wiring and stuff $100

This will give you 1000w to play with I would think, assuming you get 2 hours of sun a day. Otherwise, you are going to have to rely on the generator.

That’s the hitch.
A 12$ electrical part died on the generator the night prior to camp breakdown, and left me scrambling out in the forest.
Thankfully, this isn’t a particularly price sensitive project.
It is a thoughtful one.

Once I get back to town, I’ll run the spreadsheet of the energy audit (I can believe I was doing those during the Carter/Reagan years) and break the puzzle down more thoroughly.

This is a fun project, and one I’m happy to share.

I am reluctant to strip the coroplast heading into January on a brand new trailer though.

The as-issued batteries are between the frame rails, external to the camper. As this is a winter use trailer, that’s a problem.
All things to choose wisely on, with plenty of external consult.

 

[Gamekeeper]

Good morning everybody

It being the season and all, I completed my energy audit, and, checked it twice! Ho,ho, ho!

I rigged up a cheap, shunt based battery monitoring device, and item by item tested their 12v draw.
My results were bang on.
But because it hasn’t been cold here, I couldn’t measure the tank heaters, so I have to go with an estimate on those.

I followed Nate Yarborough’s online spreadsheet, and populated it with my data.

It was a fun study.

For a typical hunting trip, and keeping my wife comfortable while I am gone, we will consume just under 400 amp hours per day.
playing with the numbers a bit, was interesting and fun.

For example, earlier in the season, the primary power consumption would be kitchen appliances, with less than one hour energy consumption per item Per day. The convection microwave becomes the dominant consumer of wattage.
The little icemaker, while a true pleasure, surprisingly doesn’t consume that much juice, for the amount of comfort it brings.

But when you want to start operating below freezing, well all I can say is, “Danger Will Robinson!”

Maintaining wet service, and keeping the trailer comfortably warm during the day, consumes a lot of energy.

Less than 400 amp hours, but it doesn’t leave a lot of extra wattage for normal living.

So, my findings, for this size trailer, the equipment I’m using, and the conditions I intend to operate in, lead me to the following.

I should plan to install 400 amp hours of lithium, with provisions for adding 200 additional.

I should put 600w of panels on tilt brackets On the roof, and 200 additional portable watts on a separate charge controller on the ground.

that will harvest the maximum amount of power for my trailer and it’s intended use.

Is that going to be enough? Nope.
Cloudy days at low temperatures will not generate enough power to operate as normal.
600 amp hours, with some behavior modification, will get us through about three days. Possibly four.

Over paneling, and tilting the panels, should stretch the battery bank.

But it looks like I’m going to be traveling with the gasoline powered 2500 W inverter generator for the foreseeable future.

Now it’s time to find the appropriate lithium battery bank before year end, to take advantage of the tax credit.
This will be my last entry into this thread, everything related to this project going forward, will be over in the mobile vehicle based section.

Thanks guys