No generator, no problem!

[PNW_Steve]

Wrybread, you are a lucky one. not all RV's are able to fit 900w of PV on them. Sunking was speaking more in generalities, folks like to park in a shady spot, rooftop vents and stuff shades the panels, never correct orientation.....
When you are charging well, what sort of PV harvest do you see, 300w? 500w?

I must be extremely lucky.....

I am trying to decide whether the 1800 watts of panels on the roof is enough. Maybe I should go 2400?

I have the room and I have the panels. Hmmmmm...

[Wrybread]

+1 on PNW_Steve's suggestion to put panels over plumbing vents. Cut off the rain lids from those vents and use the panel as the new lid. I've also overhung the side of the RV by a few inches, especially in areas where there's already a protrusion from the RV (over side view mirrors, plumbing inlets on the side, etc). I've even seen people make racks to mount panels over AC units. That's especially common in Europe interestingly, where I think there's more of a functional utility approach to the roof of an RV than America, where people tend to try to keep things neat and tidy.

But looking out at a bunch of RV and trailer rooftops right now all I see is blank real estate. I don't see a single one that couldn't fit two 300 watt panels easily, most of them even more. And I don't see a single modern panel, just a couple of small old style 12 volt panels. And their generators are already running in the middle of the day even though it's cold enough here on the Northern California coast that most people are wearing jackets.

[PNW_Steve]

I guess RV roof real-estate has gotten larger over the years. Vents and air conditioner housings used to break up the roof and not be as usable

Depends on the rig. I was going to install two 300 watt panels on my 5er but, with all of the obstructions I only had room for one. My new rig is a blank slate. I have an 8'x35' empty canvas to work with. No roof airs. Plumbing vents will be under a panel.

[Mike90250]

I guess RV roof real-estate has gotten larger over the years. Vents and air conditioner housings used to break up the roof and not be as usable

[Wrybread]

> Another member made the comment that solar on RV's is near useless and not worth pursuing.

It's an oddly common viewpoint on this forum for some reason. Usually from people who have either never owned an RV, or who have old 12 volt panels and PWM charge controllers. Modern RV solar works incredibly well and it's a massive shame that it's so rare. As I'm typing this I'm looking over a bunch of RV rooftops and I only see a single solar panel, and it looks like it's under 100 watts. Absurd.

> Currently in the works is 1800 watts on the roof of my latest rig.

Awesome! I have 930 watts (three 310 watt panels), thinking about adding a 4th. Not that I particularly need it, but I have the room on the roof and the extra charging capacity comes in handy when we have long cloudy spells in the winter. And besides, they're almost free, the biggest expense is the time to mount them, so might as well!

[PNW_Steve]

Another member made the comment that solar on RV's is near useless and not worth pursuing.

I have to strongly disagree. I have installed solar on a handful of RV's and had good results. Only one of them did not have a generator. We put 1200 watts of panels on the roof of that one. The gent lived full time and lived an Idaho Winter off grid successfuly.

More recently I installed 300 watts on one of my 5'ers. It has cut my generator run time significantly.

Currently in the works is 1800 watts on the roof of my latest rig. Air conditioning will be high SEER mini-splits.

I expect minimal generator run time and will have a very limited ability to run air conditioning from solar/battery.

Solar definitely has a valuable application in the RV world.

[ewarnerusa]

Well done Wrybread! I'm also a solar proponent for campers. But I am not by any means living in it or full time, just a long weekend warrior type. But I have also operated for several years of not bothering to bring the generator along. Do I use electric power frugally? Certainly, but it isn't difficult and as you mentioned I can't really fathom what kind of power needs people are attributing to RV camper use. All LED lights mean that they hardly use any power, fridge and cooking done with propane, furnace when needed is something like 7 amps DC for the fan and uses propane to provide the heat, and the inverter runs the TV once in a while when the kids are begging for a movie after a day full of play. I charge whatever little electric gadgets need it like phones, portable DVD player, walkie talkies, bluetooth speakers, etc. Once in a while we'll fire up an electric rice cooker via inverter for a 300 watt load for cook time then something like 60 watts to keep warm. My system is 280 watts of 12V panels mounted fixed and flat on the roof, PWM controller, 2x6V GC batteries in series, 300 watt and 1500 watt PSW inverters. Although usually we just use the small inverter and I'm aware that my battery capacity is not enough to really exercise the big inverter.

Now that I've installed a Micro Air Soft Start Kit on our rooftop air conditioner, I do bring the generator along and enjoy air conditioning when the weather is super hot! But the converter breaker is still switched off when I do that, my meager solar setup satisfies our electric needs.

[Wrybread]

That's awesome Sojourner1!

@Suprasoup: very interesting setup, but definitely not typical in terms of power draw. Most RVs use propane for cooking and heating.

@PNjunction: not talking trash, just correcting misinformation about generators and the usefulness of solar in an RV that's really really prevalent on this website (or was when I was last reading it). This thread alone shows a lot of the misinformation, like that solar in an RV is expensive, or complicated, or that RVs consume as much electricity as a house, or that RV solar requires being miserly with power. I'm a huge advocate for RV solar since I hate the sound of generators, so I like to spread the word of how well modern solar works in an RV, and how easy and cheap it has become.

I can live a bit more frugally, but instead of multiple Imacs pulling 60-100 watts when idle, I run Linux on 6-10 watt mini-pc's. Or use a Chromebook or other mini-laptop that is more than adequate for most weekend warriors not trying to compile their lisp executables.

That's great, but the point is that I don't have to be miserly with power. I run Linux on small PCs too, I have a Raspberry Pi running 24/7/365 that's the "brain" in my camper. It keeps track of my solar and, most importantly, lets me turn on my heater from bed so I don't wake up to a cold RV. But I use that little computer because I like to, not because I have to. I run iMacs and regular laptops with external monitors because I prefer those and have plenty of power for them.

On a side note, attaching a few screenshots from my Raspberry Pi powered app. If I press the heater button the heater turns on for 30 minutes, and if I press the subwoofer button the sub turns on for 3 hours. The screen with the sun in the bg shows kWh for each day, and a yellow mark on top means it reached float (fully charged). There's some blank days because of user error, forgot to plug it back in for a few days. The screen with the ice cube is my fridge, and it's so sensitive that it shows me opening the fridge, which is that little bump on the graph. It'll send me text alerts if my fridge goes above a certain temp so I don't get surprised by a science experiment if I leave for awhile. The possibilities of a Raspberry Pi (or similar) in an RV are so huge.

[Sojourner1]

Wrybread, I'm in your camp as a fulltimer but "living" off of solar/ batteries. 1,280w solar/ 12v 500ah LFP/ Magnum PT100 controller/ Magnum hybrid 3000w inverter/ sub panel added/ EU2000I generator. I've had it on the 5th wheel now for almost 3.5 years and out of that all but 60 days has been traveling/ boondocking throughout the west. I'm in a stretch since Dec 22, 2016 was the last time I was hooked up to a power pole. In any given year the generator has not been used for more than 24 hours if that. When used It's for given the batteries a hold over charge, which I'll run it for 2 hours and put 200ah back into the batteries. That will happen if the SoC gets down to 30% and it doesn't look like its going to be a good solar day. This is still using microwave or coffee pot or other items at the low of a SoC.

[PNjunction]

Forgot the secret to AGM ...

Because we are not charging from a stable source of power, when in cyclic duty follow Sunking's advice for CV=FLOAT, ie don't float (or simply set the float voltage the same as the CV (aka absorb) voltage.) When cycling, this gives one the best chance to keep them alive. AND treat them to some decent panel power, like you have.

A 100 watt panel just isn't going to cut it with a battery of say 50ah or larger. With cyclic solar applications, it is very important HAMMER them to get into absorb fast. It can be done but use Lifeline's, or perhaps pure-leads from other manufacturers (which usually can't be equalized).

Sure they are expensive compared to flooded. But so is LiFePo4 lithium. A *quality* low-impedance AGM gives you some of the advantages of LiFePo4, but builds upon an existing base of lead-acid knowledge. If you can keep these healthy by following directions, and not using trash from the outset, you may not really need to go lithium.

Lifeline put out about a year ago a good set of 4 or 5 video "tech talks" (in front of a VERY nice RV by the way), showing some great generic info, equalization (15.5v) on a recoverable, and non-recoverable abused battery, the joke of only using a 100 watt panel in the second video etc. Not really covered is the admonishment that in a CYCLIC solar setup, the importance of using CV (14.4v temp comp), and NOT floating, but keeping CV and float the same until the sun set. Going into float too soon is an agm killer with cyclic solar. Most of the 15.5v EQ is an attempt to compensate for undercharge, which solar will do if it goes into float in a daily cyclic application. Adjust accordingly if traveling to the equator.

A weekend warrior WILL want to use a 3-stage algo which eventually goes to float. But for daily cyclic: keep at the CV value and float value the same (14.4v temp comp for Lifeline's) until the sun itself pulls the plug.

[PNjunction]

Wrybread - you've got some decent panel power, and that's key.

How about this challenge since you seem to have a knack for proper battery maintenance, and as a possible stepping-stone before trying lithium:

See if you can hack using a Lifeline AGM - one of the very few that *can* be equalized! You'll love this 40 page manual (see the Lifeline Technical Manual PDF link) here:

https://lifelinebatteries.com/knowledge-center/

I think you can do it. The point being that some of the campground weekend warriors just might be able to get by with proper guidance for that no/low maintenance need for those who you KNOW aren't going to be using hydrometers.

Being able to absolutely hammer them, similarly to LiFePo4, might be attractive. BUT rather than call out what many here say about AGM as "misinformation", I'll just say that the naysaying often heard is more of a loving guidance for those not willing to follow specs, or attempt to use second-hand trash for their project, to stay away from agm.

Those that are willing to put the same effort into maintaining a flooded battery with proper knowledge, can also do so for AGM. Fast recharge (low impedance) means that they might have a chance with some of the "crappy" 12v installs. Many kill them with too little panel current treating them like flooded, so if you can convince them that panel power is key, these weekend warriors might find solar more attractive and THEN move to a larger setup like yours.

So the gauntlet is thrown. I can live a bit more frugally, but instead of multiple Imacs pulling 60-100 watts when idle, I run Linux on 6-10 watt mini-pc's. Or use a Chromebook or other mini-laptop that is more than adequate for most weekend warriors not trying to compile their lisp executables.

Give it a shot - I think you can do it. And may be able to assist others getting rid of AGM "misinformation". It just takes knowledge, and not starting out with second-hand trash.

Just try to keep ONE alive for practice, before moving on to multiple series / parallel arrangements. I have and think you have the chops. It's not hard, just too much bad info out there...

[Suprasoup]

Is that fridge a compressor fridge? If so, awesome, I've always wanted to try one meant for off grid use. Especially the Danfoss compressors.

Dometic CF110. It is a compressor (danfoss) refrigerator capable of running off 12/24v dc as well as 110 ac. It is very efficient. In its custom enclosure it uses roughly 150-200Wh/day.

The other stuff, in my opinion, isn't oriented to using solar. That system was designed with a generator or RV park in mind. With a little bit of a change in planning (propane heat and stove) it's possible to use solar (and propane) for everything except the air conditioning. I'm living and long term proof of that. And of course technically I'm using solar *and* propane, but that's silent (most importantly!), on demand, much less messy, easier to maintain, has no moving parts, cheaper, has no stinky exhaust, and is much much much more efficient. A generator just isn't an efficient way to cook food, and chances are your neighbors would rather listen to the birds than a generator.

Everyones energy needs are different. While 2kWh works for you it doesnt for most RVers. I just pointed to things in my own rig that I use on a regular basis. Others are different. You are also assuming that I use a genny which I do not. Like you I value peace and quiet. I would add solitude as well. You will never find me in an RV campground.

But I think you're at least as much of an outlier as I am with your extreme reliance on electric appliances in an RV. Most RVs and trailers don't have all electric appliances, and for good reason. Even if you don't mind using a generator with all of it's inefficiency and noise, at my campground for example there's no hookups and you can't run your generator until 8am, so if you're an early riser you're going to have to wait to make that coffee.

Agreed. Each of us makes different decisions based on our needs and priorities. In my case I preferred not to use propane nor rely on a generator. So I loaded as much solar and batteries on my trailer as I could. My trailer weighs 1500lbs loaded. Want to guess how much of that is the panels and batteries? And to the last, LOL. If my day started at 8am I would have been killed in an backcountry avalanche or struck down by an afternoon thunderstorm alpine climbing years ago.

I know someone who just built his custom dream van ($100k for a Class B, oof) with an induction stove top and it's been a massive nightmare for him, totally dependent on running his generator. He thought he'd be able to power it from his inverter but he was wrong, so he mostly uses a crappy little camp stove for his day to day use since he usually doesn't want to deal with the gennie just to cook. That strikes me as bad planning but of course your mileage may vary.

I have been thoroughly impressed with my induction cooktop. Its a 1500w double burner one that shares the 1500w between the two burners. My inverter has no problem running it. I rarely cook for more than an hr/day. I have a little jetboil as well but it sucks for cooking steaks.

I'm not suggesting you switch out anything in your RV, writing the above with people planning their RV in mind.

I agree with a lot of what you are saying. Properly size a system on an RV or trailer for your daily energy use and you probably wont need that generator or isolator that often. But most of us dont guess our daily energy use well hence why 99% of systems arent sized properly. I was very fortunate to find this site when I was designing my system. I attribute my trailers solar success to the fine folks here.

[Ampster]

Incorrect? Ever heard of free will?
I glad that you have found the perfect balance of electronics and solar generation. My RV friends have a lot of variety in the amount of power that they choose to use. While I am a strong advocate for solar I can't expect them to stand in my shoes.

[Wrybread]

Is that fridge a compressor fridge? If so, awesome, I've always wanted to try one meant for off grid use. Especially the Danfoss compressors.

The other stuff, in my opinion, isn't oriented to using solar. That system was designed with a generator or RV park in mind. With a little bit of a change in planning (propane heat and stove) it's possible to use solar (and propane) for everything except the air conditioning. I'm living and long term proof of that. And of course technically I'm using solar *and* propane, but that's silent (most importantly!), on demand, much less messy, easier to maintain, has no moving parts, cheaper, has no stinky exhaust, and is much much much more efficient. A generator just isn't an efficient way to cook food, and chances are your neighbors would rather listen to the birds than a generator.

But I think you're at least as much of an outlier as I am with your extreme reliance on electric appliances in an RV. Most RVs and trailers don't have all electric appliances, and for good reason. Even if you don't mind using a generator with all of it's inefficiency and noise, at my campground for example there's no hookups and you can't run your generator until 8am, so if you're an early riser you're going to have to wait to make that coffee.

I know someone who just built his custom dream van ($100k for a Class B, oof) with an induction stove top and it's been a massive nightmare for him, totally dependent on running his generator. He thought he'd be able to power it from his inverter but he was wrong, so he mostly uses a crappy little camp stove for his day to day use since he usually doesn't want to deal with the gennie just to cook. That strikes me as bad planning but of course your mileage may vary.

I'm not suggesting you switch out anything in your RV, writing the above with people planning their RV in mind.

[Suprasoup]

I still don't understand what you (or these "99%") are using that consumes so much power. And my point is that ultimately I think you're incorrect. 2kWh is definitely not nothing in an RV. I'm in it essentially full time with multiple computers running all day. My iMac pulls the same as a TV. What else do you think people need to run?

Not in an rv but a travel trailer. For months at a time I dry camp outta my Zombie Trailer in the desert Southwest. My setup is completely electric, including an induction cooktop, 24v dc refrigerator and heated blankets on the bed. I run a window ac in the summer to take the sting outta sleeping in a sardine can. In the winter I use an iron to wax snowboard and skis, I have a small radiant heater that I set to low (200-300w) to take the chill off. 2kWh isnt much when you move away from propane for cooking, refrigeration and/or cooling and heating. Kudos for you for being energy miserly but I would agree with others that you are a rare exception.

Not that Sunking needs defending, he can easily do that himself!, but I have always found his advice reasoned and well thought out.

Zombie Trailer statistics.
2 x 320w panels.
4 x 6 Trojan L16 370ah batteries. 24v system.
24v 1500w Go Power inverter.
30a Tracer BN series mppt charge controller.

The tow vehicle has an additional 150w of solar panels that I link to the trailer when I am stationary.