2200 watts of solar on the roof?

[dreadlocks]

LFP puts the generator back on the table IMO.. I know most everyone is adverse to em, but some simple math compared to FLA.. no matter the size of your FLA bank going from 50% to 100% is a 6-7h endeavour at maximum charge rate.. its 2.5h for LFP at maximum charge rate to go from 5% to 100%, so pretty much double the storage capacity in half the time.

If your shooting for 7h of runtime a week on a genset to keep fuel/noise/etc down.. you need to build a Lead bank that can go a full week.. With Lithium, you could go for a bank that only needs ~1h a day, or 2h every other day.. Well if 100AH LFP gets me 2h every other day, lets say thats a ~45AH a day diet.. now to go a week on lead, I need a 45*7*2=630AH lead bank to have same equivalent engine runtime as a 100AH LFP bank.. thats a $400 price difference from GC2's and a BB for almost 400lbs in weight savings.. I'll take $1 a pound any day.

Nobody wants to use a genset for a lead bank, you run the engine a frigging buttload.. and most of the charge the genset is wasting more energy than the batteries are taking.. if your genset idles lowest at 400w and your bank is taking 100w thats just burning money..

With LFP on the other hand its new paradigm.. taking max current until full means your genset is not idling and can actually reach efficiency, and much shorter times.. and all this same stuff rolls over to the solar.. you can now hookup enough solar to recharge in a few short hours of sunlight, its so much easier to get a 2-3h of direct sunlight on your mobile roof a day, or a full day of partial but useful output, than it is to get 7-8h of good light consistently in the real world.

The ideal system I'd build if I had your money would be ~200AH of LFP w/2000W of Solar, 2000W of Generator Charge, and 2000W of Engine Charge.. be it sunbathing, driving, or boondocking you can get your 4800KWh LFP bank back to full in 2.5h, and that should be enough energy you can be obscene with usage full time living without ever sweating a thing.. I'd never have to think about anything because it'd just be all automated.

 

[MTVR]

...you forgot the 2000W of shore power, lol...

 

[MTVR]

So as far as 200Ah of lithium, are you talking about FOUR 100Ah Battleborns in series/parallel for 200Ah at 24VDC? I don't know if I can afford an electrical system based on $4,000 of batteries.

A Honda 2200i generator would be roughly another grand.

A 24VDC to 24VDC 40A charger would be what, a couple hundred bucks?

A 30A shore power connector and 24VDC 40A charger would be a couple hundred bucks?

...and then we get to the 2,000 watts of solar panels and MPPT solar charge controllers. I can't seem to find the Panasonic N250 panels for sale here in the U.S. And what charge controller(s)?

And inverter(s), monitor(s), switch(es), wiring, thermostatic cooling fan, and...

Is there some way to scale this back, and still be able to run the A/C when it's hot out?

 

[nathane]

You have a disconnect here, I'm not talking about replacing your Solar Panels w/a Onan Onboard genset.. You keep your solar panels on the roof and instead of using your drive engine as a backup charge source you use your genset, you can still use your drive engine when driving, but when your parked thats just terrible for it.. since we're talking backup power source, even in 3-5 years full time your talking less fuel use than you'd of got idling a big military engine for the same purpose..

Solar is not a panacea, even with massively oversized solar there are times of the year where your only getting a small fraction of its output, an inch of snow on the panels? 0W out of your 2kw solar.. parked in a forest with overcast? 200W would be 10% output which is what you get in diffuse/shaded output.. then you got winter where the sun is low in the sky, the angle of attack is almost always coming through trees, or hard to break into a valley.. you might be lucky to see 10-20% output of that big massive solar setup.

A generator for backup when the sun gods have forsaken you is better than a military drive engine as far as efficiency is concerned, and your going to be relying on it here and there alot more than you think.. but with a fast charging bank, your talking like 2.5-3h of runtime to get you from empty to full, thats nothing really in grand scheme of things.. if your 6-7h of genset a week in bad solar, and your at like 40% bad solar days a year thats a mere 156h of runtime a year to fill the gaps.. after 5-6 years your backup power system will be still under 1000 hours.

Then this double wammy's your aircon issue, if you only use it on rare occasion.. just use the damn generator on occasion and the deal is done..

You have to totally ignore all the solar calculators you find online, those are for fixed installs.. you know, where you chop down some trees and make a clearing that has ideal sun exposure all year long.. your mounting em all to your roof and living a nomadic lifestyle, your never going to be able to predict the weather and location and how much sun you get or anything.. I think its awesome your planning for a mega 2kw solar build, but only because its so overbuilt that in tough solar conditions.. even at a 10% output in cloudy conditions, your getting more than most of us here do on a perfect day on the summer solstice.

Gotta plan for the worst and hope for the best, and its one of the strong advantages to LFP banks.. you can overbuild solar so much that those bad days you can survive, while still being able to utilize that over paneled capacity to capture short bursts of sunlight coming through the clouds/trees, or just simply burning it on frivolous energy usage when there's more sun than you need.

This is definitely true. We have had beautiful clear sunny days here in the UK last few weeks and I've got max 280W from 1.1kw panels

 

[Joe917]

MorningStar MPPT 60 charge controller.
Brand of panel does not matter too much.

 

[nathane]

So as far as 200Ah of lithium, are you talking about FOUR 100Ah Battleborns in series/parallel for 200Ah at 24VDC? I don't know if I can afford an electrical system based on $4,000 of batteries.

A Honda 2200i generator would be roughly another grand.

A 24VDC to 24VDC 40A charger would be what, a couple hundred bucks?

A 30A shore power connector and 24VDC 40A charger would be a couple hundred bucks?

...and then we get to the 2,000 watts of solar panels and MPPT solar charge controllers. I can't seem to find the Panasonic N250 panels for sale here in the U.S. And what charge controller(s)?

And inverter(s), monitor(s), switch(es), wiring, thermostatic cooling fan, and...

Is there some way to scale this back, and still be able to run the A/C when it's hot out?

It's pretty hard to run a.c. off grid without running a genset or spending $$$ on batteries.

 

[MTVR]

A generator AND $2,000 of batteries would be a lot easier for me than a generator and $4,000 of batteries.

What about something like ONE 100Ah Battleborn (at 12VDC, obviously), 500 watts of solar, one MPPT solar charge controller, run our fridge off a small inverter, run our lighting and water pump and other stuff at 12VDC, and when needed, run a small A/C unit directly off a Honda 2200i.

In fairness to the generator idea (that I was really hoping to avoid), we will have two gasoline-powered motorcycles onboard, so adding gasoline would not be adding another fuel for us. I would be more inclined to do the Honda 2200i than the Cummins-Onan diesel, because the Hondas are so fuel-efficient (for gasoline-powered generators), and mostly because they are so darned quiet.

I would need to find a sturdy lockable ventilated generator box to mount to our platform and paint to match the vehicle...

 

[dreadlocks]

...you forgot the 2000W of shore power, lol...

Generator is Shore power, Shore power is Generator.. they are interchangable, your clearly never going to be using em both at the same time.. and its moot w/shore power because you dont really need to recharge in 2.5h unless your recharging your giant truck at an EV charging station, if you do that please take pics!

So as far as 200Ah of lithium, are you talking about FOUR 100Ah Battleborns in series/parallel for 200Ah at 24VDC? I don't know if I can afford an electrical system based on $4,000 of batteries.

A Honda 2200i generator would be roughly another grand.

A 24VDC to 24VDC 40A charger would be what, a couple hundred bucks?

A 30A shore power connector and 24VDC 40A charger would be a couple hundred bucks?

...and then we get to the 2,000 watts of solar panels and MPPT solar charge controllers. I can't seem to find the Panasonic N250 panels for sale here in the U.S. And what charge controller(s)?

And inverter(s), monitor(s), switch(es), wiring, thermostatic cooling fan, and...

Is there some way to scale this back, and still be able to run the A/C when it's hot out?

If you build a 200AH 24VDC LFP bank it would be dramatically cheaper, and at this money level I think it'd be worth doing.. I bought my singular BattleBorn because I was a noob and it was a small system.. were I to start over today, Battleborn would go pound sand and I'd be building my own pack with cells I can individually monitor and replace, with a BMS that handles all my cells and not just 1/2 or 1/4 of em..

You can scale this back, your solar in ideal sun wold be limited to half output, cut all your charge sources in half and only ever run your AC off genset/engine.. the idea of running AC off Solar is relegated to the heap of really cool but vastly impractical dreams.

 

[MTVR]

If you build a 200AH 24VDC LFP bank it would be dramatically cheaper, and at this money level I think it'd be worth doing.. I bought my singular BattleBorn because I was a noob and it was a small system.. were I to start over today, Battleborn would go pound sand and I'd be building my own pack with cells I can individually monitor and replace, with a BMS that handles all my cells and not just 1/2 or 1/4 of em..

Elucidate...

 

[dreadlocks]

I do not endorse any of these, just quick results from 'building a large LFP bank' on the google.

Assembling a Lithium Iron Phosphate Marine House Bank | | Nordkyn Design

This article describes the process of designing, assembling and balancing a lithium battery bank for use on a yacht.

nordkyndesign.com

TLDR: You find a source for quality LFP prismatic cells (easier said than done), bolt em all together in a housing that resists swelling, add a Battery Management System (BMS) that is wired up to each cell individually so it can monitor their individual voltages.. the BMS controls big solid state relays for incoming and outgoing current, and shuts things down when operating parameters are violated, like too much discharge, too much charge, low SOC, too high temps, trying to charge when below freezing, etc.. If you were to crack a battleborn open you'd find pretty much all the same stuff, just hidden away where you cant access it or do field repairs on it.. you can also program in your own safety parameters if you want to be even more conservative than a drop in manufacturer for super long service lifes.

Raw prismatic cells are nearly half the cost of a fully assembled battery, so for the same money a DIY system could be nearly 2x as large.

 

[Alloy]

A generator AND $2,000 of batteries would be a lot easier for me than a generator and $4,000 of batteries.

What about something like ONE 100Ah Battleborn (at 12VDC, obviously), 500 watts of solar, one MPPT solar charge controller, run our fridge off a small inverter, run our lighting and water pump and other stuff at 12VDC, and when needed, run a small A/C unit directly off a Honda 2200i.

In fairness to the generator idea (that I was really hoping to avoid), we will have two gasoline-powered motorcycles onboard, so adding gasoline would not be adding another fuel for us. I would be more inclined to do the Honda 2200i than the Cummins-Onan diesel, because the Hondas are so fuel-efficient (for gasoline-powered generators), and mostly because they are so darned quiet.

I would need to find a sturdy lockable ventilated generator box to mount to our platform and paint to match the vehicle...

Our 2600W has been great in winter Nov. to Feb. (tilted) and in the forest (portable) but if you won't be doing much of either I'd maximized the panels for one controller and leave room to add a 2nd controller&panels.

As per deadlocks start with min 200Ah but leave room to expand the bank. Everlanders page has some good info on solar/lithium

Everlanders

Hello, We are Jason & Kara of the Everlanders, Follow along as go from the early stages of building our off-grid home on wheels, to selling our house and tak...

www.youtube.com

Generator box and portable generators are a hard mix. The exhaust needs to exit the box and there is no fan to cool the engine.

It's nice to get the generator away from the vehicle to reduce noise/vibration. In winter we dig a snow cave for it. If needed (rarely) in summer we put it behind a tree or down the slope always watching for fire hazards (we've seen a generator caused grass fire) and bringing it back onto hard ground for re-fueling.

We also have an extend run cap for the H2000 generator.

Camping Generators for sale | eBay

Get the best deals on Camping Generators when you shop the largest online selection at eBay.com. Free shipping on many items | Browse your favorite brands | affordable prices.

www.ebay.com

 

[MTVR]

Fan-cooled ventilated locking generator box.

 

[dreadlocks]

just built that onan diesel genset onboard, you wont need to carry any extra fuel and you can set it up so when your bank gets low it automatically starts the genset (if its not quiet time) and charge the batteries, then shut down when its full.. all automagically because its got remote electric start and a fuel tank it could not empty by itself..

I'd be looking for a diesel pusher RV getting parted out or in a salvage yard to snag its lightly used diesel onan for your truck.

 

[MTVR]

...that's the other option...and if I build it onboard, it will be in a manner that makes it less likely to walk away when our vehicle is unattended.

I am a little concerned about the noise from the Cummins-Onan. I've seen numerous videos of people trying to quiet them down. The Hondas are so quiet.

We do not intend to hang out in any place that has a "quiet time".

I wonder what the real-world fuel consumption is like, as compared to the Honda EU2200i...

 

[dreadlocks]

Its a good idea really.
Since this topic is devolved to a form of electro-daydreams and wanking...
Might as well fit a SAE J1772 inlet along with NEMA TT30 to the battery charger. Recharge your housebattery whilst at the Mall or Walmart.
Btw, I am not entirely sarcastic, its really a decent and electrically sound idea.

This is what I'm thinking of doing to my Diesel Westfallia project, its small enough to fit in EV parking fine and I wont be able to carry as much solar as I need on the fiberglass poptop.. at least when were shopping at kroger or something it can be sucking up the amps w/out running the engine.. Since I've also got to retrofit air conditioning into this 1975 vehicle I was thinking of putting either a 2nd 120VAC compressor motor into the loop, or a double clutch on the engine AC compressor with a small electric motor to drive it separately.. then plugged into an EV spot I can leave the AC running which would be pretty sweet for the doggos.


back on track, yeah a thumper diesel motor is gonna be a bit loud, but will it be louder than your AC? not like its all piece and quiet when that things whirring along either.. and when using for recharging if automated you could just have that go off when your out fishing or hiking or away for an hour or so and u never have to put up with it.. it'll stop when bank gets full.. at least you wont have to endure it running ALL DAY LONG like those campers w/lead banks.