Advice on boon-docking solar setup.

[BrutusBus]

Hey all,

Our plan is to travel without worries of needing to hookup.

Currently, we run off of a 3500 inverter generator to our 30amp hookup when we are not connected to shore power (at campgrounds). We hook up when we can, but we want to explore more (we are heavy into mountain biking).

Necessities;

1) A/C. We know we will need a big system to power the 13,500 but AC, but it only needs to run 2-4 hours while we are gone, biking, to keep the pups cool. We have a 150lb St. Bernard & a New Foundland, so their hot breath counteracts 90% of the A/C - so we have to factor that in. Once we are backk, we can pop on the generator to take over. Now, if we stay in that same location overnight, we would prefer to have the generator off when we sleep and run off of batteries/solar.

We have 30ft of roof top decking, so space is not an issue. I also, just this morning, saw another skoolie with hinged panels off the side of the bus. This is totally an option for us also, to save some enjoyment area on the top deck. Space is not an issue, and we are perfectly ok with making what we need work.

2) Fridge. We have a small 4.6cu Fridge that we would like to run 24/7.


That's all! As long as we can keep the AC and Fridge running, we will be able to go on our bike trips, the pups will be happy and cool, and the food will stay cold.

I've been researching all I can, but for some reason I am just not understanding how to piece together a proper setup for our needs. The conversions, and electrical wording, just hasn't clicked for me yet, and it's been frustrating trying to learn.

Any help is appreciated! Thank you!

[john61ct]

To the extent you try to run aircon off stored energy, you're talking thousands of dollars.

Solar will be a small contributor, genset the majority while off grid, with a high budget for fuel.

Focus on reducing the cubic space being cooled, tightly sealed so all ventilation is well controlled and thick high R-value insulation like a reefer box.

Since you are mobile following the 60's is the way to go.

[mrpincher]

If you research my previous posts you'll see it wasn't that long ago that I was asking the same questions you are. My only qualification for giving advice is; my system works perfectly for my needs. My electrical experience prior to reading about solar power was doing residential wiring in my own house. I am very careful and study what I'm doing before I turn on a switch.



You can get all the answers you need by researching this site and the DIY Solar Power Forum, like I did. It took me well over a year to prep, purchase, install my system.



This is one valuable I've learned since building my own system and using/relying on solar power: your post describes the AC unit being the biggest electrical device in your bus so, build your system with a minimum solar panel collection capacity to run your AC without relying on the batteries. My system charges my batteries by 1:00pm each day in North Texas. That leaves 100% of my solar power voltage to be dedicated to running my AC. I have a 12000 BTU Pioneer mini-split (recommended on this site) and it runs from the six 300W panels mounted flat on my roof. I bought the panels from Santan Solar in AZ.



I run my AC from around 1:00pm thru 10:00pm almost every day. I rely on my batteries to run the AC from around 6:00pm thru 10:00pm. Doing that discharges my batteries by about 20%. I gain all that 20% back before 1:00pm the next day. note: I have a 1000W microwave and a 10cu ' residential fridge from Lowes. I live/eat/cook in the bus exactly like I do in the house. I have an inverter that will run the Microwave,LED lights, small TV, fridge, and AC all at the same time (for 5 minute bursts). My bus is very well insulated.



My attempt here is to give you a target (size) for your system. I had difficulty deciding HOW big to build my solar power system. Be sure your solar panels will run the AC and maybe some extra capacity to keep trickling volts into your LiFePo batteries.



I gotta say that solar power is a beautiful thing when the sun is shining and the volts are chuggin through your system. Its an amazing technology that really works.



Good luck
Mike

[mrpincher]

Originally Posted by john61ct

To the extent you try to run aircon off stored energy, you're talking thousands of dollars.

Solar will be a small contributor, genset the majority while off grid, with a high budget for fuel.

Focus on reducing the cubic space being cooled, tightly sealed so all ventilation is well controlled and thick high R-value insulation like a reefer box.

Since you are mobile following the 60's is the way to go.

John is absolutely right - I relied on his advice all the way through my project. My system cost 3, 4, or more, times the purchase price of the bus. I wasted a lot of money building my system because I'm a novice. Learning is expensive sometimes.


Mike

[kazetsukai]

Originally Posted by BrutusBus

Our plan is to travel without worries of needing to hookup.

Okay, what is your budget?

Originally Posted by BrutusBus

Currently, we run off of a 3500 inverter generator to our 30amp hookup when we are not connected to shore power (at campgrounds). We hook up when we can, but we want to explore more (we are heavy into mountain biking).

This can be a component of your system, some inverters have ATS/charge with automatic generator start.

Originally Posted by BrutusBus

Necessities;

1) A/C. We know we will need a big system to power the 13,500 but AC, but it only needs to run 2-4 hours while we are gone...

2) Fridge. We have a small 4.6cu Fridge that we would like to run 24/7.

That's all! As long as we can keep the AC and Fridge running, we will be able to go on our bike trips, the pups will be happy and cool, and the food will stay cold.

This is not as hard as some are making it out to be I think.


My system I wanted not to worry about hookup, ever, for everything. AC, full sized household fridge, laptops, water filtration, TVs, you name it. A "residential electrical experience" I call it. When I went full time I had enough in solar panels, but not enough battery capacity to keep things going. I just did a retrofit with new batteries and a new inverter and now I think I'm more or less off-the-grid for everything, and I think I have around $9000 into my electrical all-in-all, over half of which is batteries.



For your uses I don't think you need to go that far. I think as many panels as you are willing to put up (around 2000W minimum) combined with a modest battery bank and decent inverter will do the job.


Have you measured how much the AC you want to power pulls?

[BrutusBus]

Originally Posted by kazetsukai

Okay, what is your budget?

No real number set to it. More so would like to get the ball rolling with a ~$3-5,000 and be able to upgrade if needed, or if we don't meet the supply right off the bat. Anything is an upgrade from where we are at - zero.

Originally Posted by kazetsukai

This can be a component of your system, some inverters have ATS/charge with automatic generator start.

Ours is pretty basic - we talked about it in another thread. I can exchange this one for one that does at ATS/Charge is Champion makes one. Or I can return and go find another option - any in mind?

Originally Posted by kazetsukai

This is not as hard as some are making it out to be I think.

AC and fridge. I run my computer not too often, and we have really minimal lighting, and a small water pump we manually turn on and off.

Originally Posted by kazetsukai

My system I wanted not to worry about hookup, ever, for everything. AC, full sized household fridge, laptops, water filtration, TVs, you name it. A "residential electrical experience" I call it. When I went full time I had enough in solar panels, but not enough battery capacity to keep things going. I just did a retrofit with new batteries and a new inverter and now I think I'm more or less off-the-grid for everything, and I think I have around $9000 into my electrical all-in-all, over half of which is batteries.

That's the end goal. Park anywhere we want, not have to bat an eye at "where do we hook up?!" and go about adventuring. We are full timers as well, so this is a long term invest in my eyes.

Originally Posted by kazetsukai

For your uses I don't think you need to go that far. I think as many panels as you are willing to put up (around 2000W minimum) combined with a modest battery bank and decent inverter will do the job.

Seems the 100W panels are cheap, but 20 panels would be wild. (7) 300w panels would fit well and leave roof storage and an area for hanging out.

Originally Posted by kazetsukai

Have you measured how much the AC you want to power pulls?

Not yet, it's on my immediate list. A clamp meter would be best?

[kazetsukai]

Originally Posted by BrutusBus

No real number set to it. More so would like to get the ball rolling with a ~$3-5,000 and be able to upgrade if needed, or if we don't meet the supply right off the bat. Anything is an upgrade from where we are at - zero.

I think you can get somewhere with that figure.

Originally Posted by BrutusBus

Ours is pretty basic - we talked about it in another thread. I can exchange this one for one that does at ATS/Charge is Champion makes one. Or I can return and go find another option - any in mind?

The inverter is the one with ATS/charge, not the generator. The idea being, the inverter can detect when the batteries are low and start the generator to switch over (and begin charging) automatically.

Originally Posted by BrutusBus

AC and fridge. I run my computer not too often, and we have really minimal lighting, and a small water pump we manually turn on and off.

Again, sounds fairly modest/midsized.

Originally Posted by BrutusBus

That's the end goal. Park anywhere we want, not have to bat an eye at "where do we hook up?!" and go about adventuring. We are full timers as well, so this is a long term invest in my eyes.

Just keep in mind, all systems require monitoring. No solar system just hums away without the owner/operator taking a look from time to time. For me its, check my solar intake for the day, what was yesterday like, what are my voltages like right now, how much energy have I used. My new batteries are very new still so I'm still feeling them out, but while I don't worry too much about running out, I still watch the system.

Originally Posted by BrutusBus

Seems the 100W panels are cheap, but 20 panels would be wild. (7) 300w panels would fit well and leave roof storage and an area for hanging out.

Craigslist often has local ads for 300w-range panels that are second hand- either mildly used or bought and never used. Last I shopped around, I had panels in my truck bed for well under $0.50 per watt- 3000W for around $1100 overall.

Originally Posted by BrutusBus

Not yet, it's on my immediate list. A clamp meter would be best?

Yeah, or one of the kill-a-watt meters. Peak instantaneous wattage and average wattage (or consumption over the period of an hour) are figures I'd be looking for.

I helped another user here design a 24V system, if you'd like I can share the wiring diagram here.

[LargeMargeInBaja]

A contrarian opinion...
.
After decades of full-time live-aboard, we are eliminating stuff.
We are reducing our electrical needs by eliminating electrical equipment.
.
An example:
* for a fridge-freezer, we acquired a used SnoMaster 61qt.
This's rated at an extremely low DC draw.
.
After a couple-three weeks, we realized we rarely use it!
Unplugging equipment reduces our electrical needs further.
.
We switched from staying up late, listening to radio while lighting the place like a carnival... to going to bed around sunset.
.
These days, we tend to eat raw or lightly-steamed, so our cooking requirements are reduced as well.
.
I think I need to point out;
* at no time are we 'doing without', living in a 'have-not' mentality.
We have everything we need, we just need less of it.

[john61ct]

Yes. Best IMO to start out that way, basic camping mode.

If you simply cannot live without something after 4-6mo then plan to put it in

[kidharris]

Originally Posted by BrutusBus

Hey all,

Our plan is to travel without worries of needing to hookup.

Currently, we run off of a 3500 inverter generator to our 30amp hookup when we are not connected to shore power (at campgrounds). We hook up when we can, but we want to explore more (we are heavy into mountain biking).

Necessities;

1) A/C. We know we will need a big system to power the 13,500 but AC, but it only needs to run 2-4 hours while we are gone, biking, to keep the pups cool. We have a 150lb St. Bernard & a New Foundland, so their hot breath counteracts 90% of the A/C - so we have to factor that in. Once we are backk, we can pop on the generator to take over. Now, if we stay in that same location overnight, we would prefer to have the generator off when we sleep and run off of batteries/solar.

We have 30ft of roof top decking, so space is not an issue. I also, just this morning, saw another skoolie with hinged panels off the side of the bus. This is totally an option for us also, to save some enjoyment area on the top deck. Space is not an issue, and we are perfectly ok with making what we need work.

2) Fridge. We have a small 4.6cu Fridge that we would like to run 24/7.


That's all! As long as we can keep the AC and Fridge running, we will be able to go on our bike trips, the pups will be happy and cool, and the food will stay cold.

I've been researching all I can, but for some reason I am just not understanding how to piece together a proper setup for our needs. The conversions, and electrical wording, just hasn't clicked for me yet, and it's been frustrating trying to learn.

Any help is appreciated! Thank you!

How do you exercise the dogs?

[Rucker]

Originally Posted by LargeMargeInBaja

A contrarian opinion...
.
After decades of full-time live-aboard, we are eliminating stuff.
We are reducing our electrical needs by eliminating electrical equipment.
.
An example:
* for a fridge-freezer, we acquired a used SnoMaster 61qt.
This's rated at an extremely low DC draw.
.
After a couple-three weeks, we realized we rarely use it!
Unplugging equipment reduces our electrical needs further.
.
We switched from staying up late, listening to radio while lighting the place like a carnival... to going to bed around sunset.
.
These days, we tend to eat raw or lightly-steamed, so our cooking requirements are reduced as well.
.
I think I need to point out;
* at no time are we 'doing without', living in a 'have-not' mentality.
We have everything we need, we just need less of it.

We should pin this somewhere. I was just mentioning this philosophy on another post, saying 'others can say this more elegantly'! Hats off!

[Rock-N-Ruth]

Originally Posted by BrutusBus

Hey all,

Our plan is to travel without worries of needing to hookup.

Currently, we run off of a 3500 inverter generator to our 30amp hookup when we are not connected to shore power (at campgrounds). We hook up when we can, but we want to explore more (we are heavy into mountain biking).

Necessities;

1) A/C. We know we will need a big system to power the 13,500 but AC, but it only needs to run 2-4 hours while we are gone, biking, to keep the pups cool. We have a 150lb St. Bernard & a New Foundland, so their hot breath counteracts 90% of the A/C - so we have to factor that in. Once we are backk, we can pop on the generator to take over. Now, if we stay in that same location overnight, we would prefer to have the generator off when we sleep and run off of batteries/solar.

We have 30ft of roof top decking, so space is not an issue. I also, just this morning, saw another skoolie with hinged panels off the side of the bus. This is totally an option for us also, to save some enjoyment area on the top deck. Space is not an issue, and we are perfectly ok with making what we need work.

2) Fridge. We have a small 4.6cu Fridge that we would like to run 24/7.


That's all! As long as we can keep the AC and Fridge running, we will be able to go on our bike trips, the pups will be happy and cool, and the food will stay cold.

I've been researching all I can, but for some reason I am just not understanding how to piece together a proper setup for our needs. The conversions, and electrical wording, just hasn't clicked for me yet, and it's been frustrating trying to learn.

Any help is appreciated! Thank you!

Hi and welcome to the life. Ruth and I live in the Chihuahuan desert of SW New Mexico. Our 40' International AMTRANS is home and completely free of the grid. We have a generator that never needs running and we stay comfortable powered by Solar alone.

Our Solar system:

• Twelve 327W Sunpower panels
  PowerJack 8000W Split Phase inverter
  3 MRpowr 60A Solar controllers
  6 BYD 24V LiFeP04 220Ah Batteries (in parallel)

Powers:

• 7.5 CU' Deep Freeze (24/7)
  Two 4.5 CU' Refrigerators (24/7)
  12,000 BTU Mini-Split (24/7) 800w-1300w Cooling/Heating *Note- Much more efficient than a rooftop unit.
  InstaPot - 800w - 1200w (2hrs/day/3-5 days/week)
  Lasko blower fan 100w-205w 4-6hr/day (helps keep the temp homogenous from rear to front. Mini split is in the rear.)
  50" TV 150w 4-6 hrs a night.
  Various phone chargers and two laptops stay plugged in 24/7
  Sound bar 80w 12 hrs a day
  MIcrowave 1200w 30min/day
  Coffee maker 1200w 45min/day
  Toaster Oven 1800w 10-15 min/day
  Oxygen concentrator 900w 12 hrs per night
  two Bi-Pap machines 6-10 hrs/night

Our panels provide ample power to charge our huge battery bank and power all of our electrical needs from about 8 am to 4 or 5 pm before we begin to see a small draw on the batteries. Generally between 11am and three pm each set of four panels will be producing about 1000-1300w (with the mini split running full blast.)

We started with just four panels and two BYD batteries. This worked well on full sun days but that was before the mini split. 3 very overcast days could leave us with insufficiently charged batteries to make it through the night running a swamp cooler, oxygen concentrator, and bi-pap machines.

We upgraded to 8 panels and that was solved. Then we decided being hot when the swamp cooler ran out of water or the air became to wet inside the bus was no fun. We tried a couple of Air Conditioning solutions before we rested on the mini-split, which we love.

This required more battery power for the night time. We bought 4 more. This worked well till winter came and we had an unusual string of very cloudy days for a couple of weeks. After about five days we found our batteries were not being charged to 80% by the end of the day. We were running the mini-split for heat day and night. Four more panels fixed that.

We bought our panels surplus for about $150.00 each. Not available from the seller we purchased from anymore. However here is a deal that is hard to pass on:
https://shop.signaturesolar.us/produ...anel-by-hanwha

The bifacial panels can produce an extra 20% over the rated 405w with reflected light. (best achieved in ground mounted systems). You won't be likely to get much benefit from the bifacial attribute but will still get full 405w in full sun for $230.00/panel This is more watts per sq/ft than we have. You could easily achieve what we have with 10 panels and be in McMansion mode with 12 panels.

If you want to start out small and your power needs after prime sun hours are are minimal you could easily power a 1500W Air conditioner in full sun with 8 of those 405w panels.

Just a note: Real world use here in NM. Our nighttime draw with the mini-split , oxygen concentrator and Bi-Pap machines is about 1.6K-1.8K (12-14 hours of low to no sun) so worst case scenario 25 Kwh/ night This is where the big money comes in. Batteries.

We have been off grid for more years than we have been skoolie. Back in 2011 we built a ground mounted system with 24 300w panels and 16 Trojan batteries. The huge, heavy, maintenance heavy, lead acid batteries had about
half the effective storage of our current system. Particularly because of how the lead acid battery storage density is defined. A 220ah lead acid battery has only about 100ah of effective storage because if you draw it below 50% you damage the batteries, so you end up only using about 40% of the rated storage before you must recharge.

When we decided to go solar in the bus we opted for LiFeP04 batteries. We planned to build our own batteries using cells like these:

https://www.dhgate.com/product/free-...hoCtEwQAvD_BwE

Our current system is made with these cells but are second hand from a solar farm.

The good news for us is that we got $14K worth of power for about $3K This allows us to live like we are grid connected, leaving the lights on, not worrying about conservation, staying cool/warm, and cooking when we like on electricity.

LifeP04 batteries are dry, can be installed in any position, weigh about 1/3 lead acid, need no maintenance, don't spill, smell, or gas off. They are not prone to fires like Lithium ion batteries. They, When used in a solar system can be more deeply discharged than lead acid batteries, though your inverter will probably not allow you to discharge below 22.5V for a 24V system. This is actually really good when it comes to longevity. You will almost never actually cycle your batteries and thus they will last a very long time.

We actually wanted to add two more of these: https://www.ebay.com/itm/392798230109

to our system but they are hard to find right now. This seller doesn't have any more.

With LFP batteries you can start out small and add to your system over time. You just need to balance the system when you add batteries. This is something that you should never do with lead acid batteries.

Things you can do to get the most out of your batteries when boondocking:

• Put your refrigeration on a timer and shut it down at sundown and turn it on at sunrise.
  Do any electrical cooking during full sun.
  Run the generator for the last couple of hours of sunlight to give your batteries a chance to top up as your power production wanes with the setting sun. Even better if you have a 20 or 30 amp DC charger running off of your your generator along with the solar.

We used the Above methods (minus the charger) when our solar system was too small and we only had the two 220ah Batteries. We burned 2 liters of gasoline each evening before the sun went down and let the sun charge the batteries for the last 2 hours of the day.

If you happen to be in SW New Mexico you can drop in and we'll show you how it all works. We do something here we call "Boondocking and Building." Where we host skoolies who want a place to build free of zone enforcement and other hassles. Boondockers get the benefit of my years of hillbilly wisdom and beautiful sunsets and sunrises for fifty bucks a week or fifteen bucks a day.

[Bert06840]

Excellent write up.

The only thing I could add is that, when you are significantly more up north, things change a bit.

[HamSkoolie]

First thing you have to do is INVENTORY your power NEEDS, WANTS, and DESIRES.


Plug them into a spread sheet.


Then assign power consumption levels to each......NOTE: Convert ALL power consumption to WATTS......


Next determine/estimate how much time per day each item will be used.


Example: a 1500 watt microwave won't be drawing 1500 watts 24/7 nor is a laundry washing machine, toaster oven, hot pot, etc. but in the extreme desert an 800 watt mini split (about 9000 BTU) may well run full bore 24/7 if you don't have good insulation.


Next determine what items are likely to be on at the same time. This is to determine your inverter size for normal and peak operations. Also don't forget that converting (inverters are converting) suffer losses. If yo calculate 10% for losses you'll be in the conservative ball park.



Size your solar panels so that they will handle your highest daytime load AND be able to put energy into the battery bank. You WILL NOT get the rated watts out of a panel except in laboratory so keep that in mind. As was mentioned, used solar panels can be a major cost savings and particularly so if you can find them close enough to avoid shipping.



Size your battery bank to handle the calculated loads. Remember, flooded lead acid type batteries require maintenance, can't be safely installed in living spaces, and can only be drawn down to 50% of capacity (golf cart batteries are a bit tougher) before damaging them. Sealed Lead Acid (SLA) and Absorbed Glass Mat (AGM) batteries don't require maintenance and in some cases are safe to install inside but they still can only be drawn down to 50% of charge before damage. Lithium batteries have their own considerations such as battery management systems but many have those built in. They have the significant advantage of being substantially lighter and able to be drawn down to 90% or more without damage. Their biggest con is cost but you're going to pay one way or another....either in heavier batteries that take up more space, require more maintenance, and have to be replaced more often or by investing a a good lithium battery bank.


Bottom line, measure or find the specs on everything electrical and get the WATTS required.




Our planned system (still refining) is 2500 watts of solar panels to drive a 3000 continuous 7000 peak (for 30 minutes) Inverter/Transfer switch/Charger in order to power 10-18 CuFt residential fridge freezer, two 9,000 BTU mini splits (probably only one at a time but one at each end of bus and able to run from the inverter) plus routers, computers, etc. along with cooking (microwave, hot pot, crock pot, etc.). The battery bank is planned for 5-10 kWh of lithium. We will have a 3500 watt inverter generator for days that there is insufficient sun as well as a roof mounted (stowed when not in use) windmill generator for those windy days at the beach.


On the other hand, a lot of that could be reduced if my other half didn't specify that those dual AC's running 24/7 in the dessert heat wasn't such an absolute requirement. LOL