Adding more panels to RV?

[sensij]

looks like current price for 100Ah CALB is $120 which would result in 10 kWh cost: (10,000 / 100 / 3.2) x 120 = $3,750 just for the batteries. Are you pricing out TOU 'shifter' solution?

I'd need about that much capacity to move completely to super off peak rate. If everything is AC coupled this would work: during mid day PV inverter feeds the loads and CC charges the batteries while later battery inverter picks up the loads. On a cloudy day CC would take energy from the grid at highest rate but then it will be returned back during the same rates anyway so it looks like no additional controller would be required at the loss caused by double conversion + battery charge/discharge efficiency: 0.98 x 0.98 x 0.8 = 0.76.

reed cundiff thanks for the info, and sharing your stories.

max2k .. nah, I over built enough that I'm not going to mess with storage for my house. We've been talking about adding a small camper, so I'm starting to look a little more closely at LFP... overkill, maybe, but a good excuse to learn.

[max2k]

If I may ask... where did you source your LFP?

looks like current price for 100Ah CALB is $120 which would result in 10 kWh cost: (10,000 / 100 / 3.2) x 120 = $3,750 just for the batteries. Are you pricing out TOU 'shifter' solution?

I'd need about that much capacity to move completely to super off peak rate. If everything is AC coupled this would work: during mid day PV inverter feeds the loads and CC charges the batteries while later battery inverter picks up the loads. On a cloudy day CC would take energy from the grid at highest rate but then it will be returned back during the same rates anyway so it looks like no additional controller would be required at the loss caused by double conversion + battery charge/discharge efficiency: 0.98 x 0.98 x 0.8 = 0.76.

[reed cundiff]

Wrybread - there is only one RV park in San Cristobal, Rancho San Nicholas. Bonampak closed a few years ago (may reopen). Churchs' book notes that do not try getting there with anything longer than 21'. They are correct. The topes are incredibly high. There is a back way in that our birding guide told us to use to get out and it was far better.

Sensij - we used Manzanita Micro for both the 5th wheel and Roadtrek. The 9+ kW-hrs in 5th wheel have been in use for four years. Our son has been in solar since 1991 (spent time at NMSU Alternative Energy Labs before that) and he designed and fabricated our systems. He is putting in a 20 kW or so residential at this time that has requested LFP and I think this will be around 30 to 50 kW-hrs of LFP. Apparently Korean companies are becoming major players. I googled this last night and a Chinese-Korean consortium will be fabricating LFP in Chile. Turns out that 50% of the easily "mined" lithium is in Chile and the Chilean government wants the lithium batteries produced in-country and do not want to remain a material exploitation nation. Son has utilized Manzanita for a few residences; however, Manzanita are designed for electric vehicles. Their batteries are CALB cells

[sensij]

We do have 1400 W of panels and 9+ kW-hrs of LFP (set at 48 V nominal).

If I may ask... where did you source your LFP?

[Wrybread]

Nice on San Cristobal, one of my favorite cities in Mexico.

Similar experience for me with solar this summer. Have yet to go below 12.2 volts, probably more like 12.4 volts. No generator, no external charging, no plug ins, never think twice about power consumption. 620 watts of panels (two 310 watt panels) into 4 Trojan T105's.

[reed cundiff]

The only time we have plugged 34' fifth wheel in during last three years is when we left it at an RV park for a week. We only go to RV parks every two or three weeks to dump and wash clothes and do not plug in since we do not trust US power lines. We do have 1400 W of panels and 9+ kW-hrs of LFP (set at 48 V nominal). We have only run generator for half an hour every month as Onan manual suggests. We spent 14 weeks in Labrador/Newfoundland in summer and 14 weeks in Mexico in winter in 19' Roadtrek (and we are still on speaking terms). We did plug in while in an RV park near Boston and then San Cristobal de las Casas (Chiapas) since we were under trees and it rained a lot. Turned it off at night and ran fridge on propane. Electricity in Mexico can be "dirty" with voltage swinging from 60 to 180 V. So we only run power through battery chargers to LFP battery banks with both systems. Chargers willsupposedly handle 60 to 180 V . There are a lot of ungrounded recepticles in Mexico and some friends plugged into a supposed 120 V which turned out to be 220 V and fried all electrical devices on at the time.

The Roadtrek has a 315 W and a 100 W panel (real estate is limited) and this required two controllers to as 12 V nominal battery suite (4.5+ kW-hrs).

Agree heartily with SunEagle's post #76

Reed and elaine

[Wrybread]

Ha good point SunEagle and will do.

All that means is a lot more panels are required

With respect, that's a simple need to fill. Two 250 or 300 watt panels instead of one isn't a big increase. I routinely pin my 40 amp charge controller at its max output with my 600 watts of panels, and those panels only cost $160 each. So you're right that the 15% decrease in efficiency from flat mounted panels requires more panels, but luckily panels are dirt cheap so it's no biggie.

[Sunking]

Solar (especially for RVs) is dead simple no matter how much you want to be the high priest interpreting the obscure texts for people. And you're living proof that professional experience gets in the way, since I've built *far* better RV solar installs than you. Charging your batteries, before your trip, hilarious!!

It is no different than any other off-grid application, same laws of physics apply. The real challenge for an RV is panels that have to be mounted on a roof with poor orientation and tilt angles. All that means is a lot more panels are required.One advantage an RV has and should be used is the engine alternator to make up for the short comings of an RV which is why they come from the factory already equipped on new models.

[SunEagle]

@ Wrybread and Sunking

Will both of you stop arguing and posting crap at each other. I am getting tired of it.

While both of you have a point to make you can do it without trashing up the threads you both like to attack each other in.

My vacation was nice and peaceful and I don't want to come back to this forum with a lot of trash talk going on. So both of you STOP IT right now or I will give you both a long vacation.

[Wrybread]

Like I said you are the idiot out on a fishing boat without a paddle or life jacket. I have over 40 years professional experience. You do not have one day of professional experience, nor any education to back it up. You are a shade tree mechanic telling people how to destroy expensive batteries.

Solar (especially for RVs) is dead simple no matter how much you want to be the high priest interpreting the obscure texts for people. And you're living proof that professional experience gets in the way, since I've built *far* better RV solar installs than you. Charging your batteries, before your trip, hilarious!

Even Sun Eagle is telling you are full of crap. Any RV user needs a alternate source of power. if not a Honda Generator like you have and use,(makes you a liar and hypocrite) then a $50 Battery Isolator to save your butt. Anyone but you can understand that. You are the guy on a boat without a paddle or life jacket.

No he isn't. He's telling me that in his experience lots of people have generators, and solar isn't very common at the RV parks he goes to. That's a big difference.

And what about the multiple people in this thread who like me never use generators? Are they lying too? For example:

@ewarnerusa

I'm of the same opinion as Wrybread, off grid campers exploring solar are often already well versed in power management and don't need an over the top, good enough for residential system to meet all of their power needs. That's why those of us successfully doing for a while have an eye rolling response with some of the advice offered in this sub forum. Solar most certainly does work terrific for the long weekend warrior off grid camper. I haven't needed a generator in years either. Hydrometer shows that my batteries are happy and healthy, they are kept at bursting full charge as the camper sits at home which is where it spends most of its time.

I have an alternative theory: you have no idea what you're doing when it comes to the practical application of RV solar. Your ideas are outdated, and overly rooted in the grid tied an large scale off-grid solar world. And you'll never learn otherwise since you're too stubborn and closed minded.

As far as me being a liar for renting a Honda EU generator to put on a "drive in movie theater" party, even though it had nothing to do with my RV and didn't charge any batteries, you *really* are reaching. And I'm starting to think you might be a little senile.

Speaking of which, I figured out how to read your posts: put them in the voice of Grandpa Abe from the Simpsons and they make much more sense!

[Sunking]

I'm living proof that not everyone needs a generator, and multiple other people in this thread are as well. This isn't theory, this is real life. I know you don't understand that. You have a lot to offer in terms of theory, but nothing to offer in terms of RV solar experience since you have next to none..

Like I said you are the idiot out on a fishing boat without a paddle or life jacket. I have over 40 years professional experience. You do not have one day of professional experience, nor any education to back it up. You are a shade tree mechanic telling people how to destroy expensive batteries.

Even Sun Eagle is telling you are full of crap. Any RV user needs a alternate source of power. if not a Honda Generator like you have and use,(makes you a liar and hypocrite) then a $50 Battery Isolator to save your butt. Anyone but you can understand that. You are the guy on a boat without a paddle or life jacket.

Here are your own words that make you a liar.

I just bring a Honda eu2000

[SunEagle]

@sunking: sorry but my reading comprehension is fine. I completely understand the point you're making, but am saying you're wrong about it being always the case. And I'm saying you don't have enough experience with RV solar to tell anyone otherwise.

I'm living proof that not everyone needs a generator, and multiple other people in this thread are as well. This isn't theory, this is real life. I know you don't understand that. You have a lot to offer in terms of theory, but nothing to offer in terms of RV solar experience since you have next to none.

@suneagle: agreed that solar on rvs isn't uniquitous get, especially in rv parks (since people without solar need to be in an rv park), but I'd argue that that's not any kind of proof that it doesn't work well. It's not like they had good solar and then got rid of it, they simply never got it in the first place. Most of those rvs probably don't have leds either, but of course LEDs work great in RVs.

And also, the era or cheap high quality solar for RVs is still pretty new. Talk to anyone with 500 or 600 watts of hard mounted solar and 4 T105s or equivalent to get an accurate picture of how well it works on an RV.

Oh. I agree that solar and an RV will work and can be a successful power supply. What I feel is that the number of people that own an RV who decide to install 500 or 600 watts of solar are few and far between. For those people that go that route, I would say they need a good understanding of solar and battery charging or the chance of those 4 T105s will turn out bad.

I have already shown you one of my solar panels systems that I plan on using either with my RV or to power incidentals in a shed that I plan to install this year. I just don't plan on every installing a permanent system on any RV that I own because my wife likes AC and that will require a working generator.

[Wrybread]

@sunking: sorry but my reading comprehension is fine. I completely understand the point you're making, but am saying you're wrong about it being always the case. And I'm saying you don't have enough experience with RV solar to tell anyone otherwise.

I'm living proof that not everyone needs a generator, and multiple other people in this thread are as well. This isn't theory, this is real life. I know you don't understand that. You have a lot to offer in terms of theory, but nothing to offer in terms of RV solar experience since you have next to none.

@suneagle: agreed that solar on rvs isn't uniquitous get, especially in rv parks (since people without solar need to be in an rv park), but I'd argue that that's not any kind of proof that it doesn't work well. It's not like they had good solar and then got rid of it, they simply never got it in the first place. Most of those rvs probably don't have leds either, but of course LEDs work great in RVs.

And also, the era or cheap high quality solar for RVs is still pretty new. Talk to anyone with 500 or 600 watts of hard mounted solar and 4 T105s or equivalent to get an accurate picture of how well it works on an RV.

[SunEagle]

I read plenty. And as I said my current 24' Class C (which is probably smaller than the Class C RV you helped with) easily fits my 4 Trojan T105s with room for 4 more if I needed them, which I don't. And it makes no difference which class of RV you were talking about, you're officially outed as having no meaningful experience with RV solar.

That's no big deal on it's own, lots of people have minimal experience with RV solar. But they don't say things like "Going off in a RV is all about unplugging and getting away from TV, phones, and internet. If you want all the comforts, use an RV park with electric hook ups and pull a car."

I just came from Cape Canaveral and from our balcony I could see Jetty Park RV area which was petty full. When I walked through it I counted over 50 RV's all different sizes and types and did not see a single one with solar panels. Granted there are trees around the camp site which would have made any production reduced but I didn't even see any dismounted panels being used. That is pretty typical of most RV places I have gone through. Solar is not a big thing for them.

[Sunking]

And remember, I'm not saying no one needs a generator. I'm saying not everyone does. The fact that you still argue that everyone needs a gennie even as multiple people give evidence to the contrary is downright amazing. .

Like I said your reading comprehension is about as good as your advice. I have said: you will want to have either a genny and/or Isolator as an alternative source of power to CYA in the event of cloudy days or unforeseen problems.

We all get your point; You are the moron out on the lake in a fishing boat without a paddle or life jacket on board in case anything happens beyond your control.