Offgrid Racetruck/ Motorhome

[MezzBatt]

Great input on here thank you gents. Someone mentioned wind issues and the old wind deflector, it's getting a sleeper pod fitted as we clack away on the keys. I will be fitting a small wind deflector forward of the first two (left & right) panels .
One interesting point made was the aspect of over panelling. One extra panel being more efficient than tilting a whole bank (in my case 4x230w 2S2P) . In the UK we like to apply KISS so have any of you done the math on tilting vs static flat...???

Power audit was mentioned, good point, it's tricky to get an accurate final usage figure at this stage. Again, I need to way up cost of going DC against domestic 230v AC appliances with inverter. I'm still very much a novice when it comes to solar, still learning loads and subject to making errors if I'm not careful so all this input from you is most valuable, thanks....

 

[ianganderton]

Great input on here thank you gents. Someone mentioned wind issues and the old wind deflector, it's getting a sleeper pod fitted as we clack away on the keys. I will be fitting a small wind deflector forward of the first two (left & right) panels .
One interesting point made was the aspect of over panelling. One extra panel being more efficient than tilting a whole bank (in my case 4x230w 2S2P) . In the UK we like to apply KISS so have any of you done the math on tilting vs static flat...???

Power audit was mentioned, good point, it's tricky to get an accurate final usage figure at this stage. Again, I need to way up cost of going DC against domestic 230v AC appliances with inverter. I'm still very much a novice when it comes to solar, still learning loads and subject to making errors if I'm not careful so all this input from you is most valuable, thanks....

2 quick points on this

Tilting vs flat

First off where do you plan to use the vehicle in the summer and where in the winter. I can provide you with info on tilting vs flat based on that info

Power audit

Unless you have a crystal ball you can’t predict actual power usage

But....

You can get pretty damn close and to be honest the process is actually more important than the answer you initially get.

By doing a power audit you will get a proper idea of what power devices and appliances actually use and what will be realistic to plan for.

What normally happens is folks think I’ll just put in as big a system as I can and that will run everything no problem

Then then add up what everything no problem might be and realise that to achieve that is actually unrealistic because either it’s just too damn expensive or there isn’t the room to generate that much power

They then start to bounce around looking at different options that optimise both their power generation and their power consumption till they end up with something that will work.

Not doing an early power audit wastes a LOT of time.

 

[ianganderton]

Pod Looks cosy but appears to open at the front. How do you get into the thing?
Not sure I'd like that. I have to get up several times in the night for ... a Pit stop, and having to get down a ladder, or even back up when I was half asleep, would not be the best thing I could do in trying not to crack my skull at some point.

Yes but it was a while ago but I remembered Right. It's 10% or less gain in tilt over flat.
I looked at tilting the panels on my 8o Shed roof and gave that up as a real bad idea. I was in 2 Minds about it for the wind factor anyway but the minimal gain was no where near the worry of lying in bed at Night listening to the howling gales we get here and wondering if the panels or in fact the roof, would still be there in the morning. There are a stack up there lying flat and unsecured and haven't moved in 3 years.
Must get them down and sell them as they arent even hooked up.

I ran the numbers for 1 KW of panels to make the percentages easier. The numbers aren't important, just the calculation is on the same amount.

1 KW of panels flat at my latitude of 34o would give an annual yield of 1252 kwh
Tilted at Ideal Tilt and facing due north ( which I would guarantee would not always be practical for you) would give 1413 Kwh.
About 10% more tilted over flat.

I also calculated for the UK as that's where you seem to be. I thought you were further away from the equator but the tilt is not that much different. You can go 35-40o but 40 is a lot to tilt a panel in an application like this.
1Kw at ideal tilt ( what a misnomer that is!) of 35o would yeild 935 Kw Hours. ( eeekk! so much less than where I am, must be a lot further from the equator. )
1Kw Flat would Yield 811 Kwh. Just over 10 % gain.

Be aware that tilt is a moving target though. It's More in winter and less in summer. The " Ideals" they give you are year averages, not the best at any time. If you had the ability to tilt you could see what it was that time of year and ajust accordingly. Your greatest benifit will be in winter BUT, you are playing with much smaller yeilds from the panels in the first place so the actual amount of power you would gain in tilt over flat is not very much at all because you are gaining percentages of maybe 1/3Rd or probably a quarter or less of the summer time yield. It's a very small gain in real watt hours over the whole winter.

Now, If we add one more 230W panel being what you have and put it flat as well, that will give an additional 187 Kwh / yr, almost double what the tilt is going to get you. If you did what I said and had 2 panels on a ground mount hinged together you could tilt and orientate perfectly, you would pick up a substantial 428 Kwh a year.
The big upside with the panels being " portable" is you could put them in the perfect orientation wherever you were even if the truck had to be parked in the shade or whatever. If it's overcast, You can just lay them down flat on the ground. Put a length of lead on them and an Anderson Connector outside the truck that hooks into the charge controller or a separate one and you are done. Fold up and store for travel, easy.

And going back to what I said before, I'll guarantee all that tilt mechanism in materials alone will cost more than a Panel, more than several panels in fact and is clearly going to be Hugely better bang for your buck keeping them flat and adding more panels.



I would STRONGLY suggest go the inverter route and just have everything as normal 240. Cabling will be cheaper, switches and outlets will be cheaper, breakers will be cheaper, you can use any appliance or tool and versatility will be unmatched.
Get a GOOD sinewave inverter from a reputable company , Wire the truck for 240 as normal and be done with it. DC appliances cost a bomb and you are limited to them. You want to add a coffee grinder or a mixer or what ever at some point, even a battery charger for cordless tools or a SMALL welder and you are stuck. If you have 240 You can use anything just like at home. If you want and have something to take advantage of it, you can always use the DC from the battery but a lot harder to go the other way.

The other thing you could look at is one of the Hybrid inverter chargers.
You can hook the solar to them and they will charge the batteries. When there is enough solar you'll get your 240 from the same unit and it won't touch the batteries. You pull into a Track or Caravan park where there is power and you can plug in the inverter to the mains and it will top up the batteries and float them so when you leave, your batteries are fully charged. You will have normal AC in the truck to do whatever you want.

Depending on the one you get, you may also be able to hook it into the trucks alternator so it is charging and providing power as you go along or just run the engine and you can get heat and power.
Would be a great idea to put a heat exchanger on the cooling circuit and use the engine heat for hot water or heat storage so you could circulate the water through a small vehicle heater setup to keep you warm.

I helped a neighbour set one of these Hybrid inverters up and was pretty impressed with it. He got a 3 Kw model which would provide full mains socket power and then some and it was around $500 of our worthless Au$$. Should be cheaper for you in Pounds worth something.
This would be an all in one solution and easy to hook up. It may be worth even buying a cheaper seperate Charge controller and a small 500W Pure sine wave inverter for spare or additional and taking with you if you are on the road. I always like to have backups of things I'm very reliant on.

Again, I'd be paying attention to the resource you have in the Vehicles Alternator. If your solar can't keep up or you want to power a heavy Load like a welder or whatever, That could be a huge assett. You could add an additional alt which would be my way to go and easily pick up a Leece Nevile brand alt as used on trucks and large boats etc that could do anything from 160- 300A @ 24V. That's the same power as a decent portable generator. I'd hook that to a step type regulator like they use on boats that would give you the fastest charging times and the most output from the lowest engine revs. Those things aren't expensive and the functionality they add to the alternator is huge.

I definitely think adding more panels and leaving the main ones flat would be a far better, cheaper and more efficient way to go and the numbers I think back that up completely. :0)

For off grid I don’t think it’s worth thinking in terms of yearly yield as it’s misleading. You have to look at average daily power generation for best and worst case (summer and winter). The UK is shit in the winter at best and non existent mostly.

Overpaneling is more a factor to do with your solar charge controller and only really factor if you have space to spare on the roof.

Your best option is to work out what is the maximum watts you could put on the roof (flat panels) and work back from there.

Give the guys here your power use age details, your location, your maximum watts on the roof and they will give you some outstanding information on the system you are best looking at including battery, SSC and inverter specs. Fusing, wiring and other structure will come from that

 

[Hedges]

To the first order, difference between flat on roof and tilted is simple area seen by the sun, trigonometry.
When sun is directly overhead, 100% of panel area is the area of sunlight on panel. When sun is just on the horizon, light is parallel to surface of panel, and 0% strikes panel.

I'm in San Jose, 37 degree latitude. Earth's inclination is 23 degrees, so summer sun angle from vertical 37 - 23 = 14 degrees. Winter, 37 + 23 = 60 degrees. cos(14) = 0.97, cos(60) = 0.5
In summer at noon, a panel flat on the roof would get 97% as much light as one oriented directly at sun. In winter, 50% as much.
Tilting the panel 45 degrees and those become 86% in summer, 97% in winter.

So if panels were on the roof with a hinge allowing tilt (not two rows where one can shade the other), climbing up a ladder to un-pin and tilt to 45 degrees would do a lot to improve winter yield.

Hanging panels on the side would be permanently tilting them 90 degrees. 24% in summer, 87% in winter. Tilting out as an awning will improve.

These assume truck is oriented so side of truck faces noontime sun.

What all this ignores is shorter length of day in winter, just considers peak output at noon. All the more reason to have way (tilt or mounted on side) to boost winter production if that is when you need power.

These are first-order calculations considering only geometry. During winter, light has longer path through atmosphere and is less intense. Off-angle light striking panel results in more reflected rather than being absorbed. Weather is a major factor. Solar calculators would do a better job of figuring out impact of angles and length of day. But a manual 0 vs. 45 degree tilt would be a big improvement.

All this means if your primary need is summer air conditioning, flat on the roof is good. (Don't forget awnings which would reduce sun's heat on side of truck, or parking in shade but then no PV production.)

Winter, tilt on roof or mounting on the side will greatly improve production (more than 50% increase in power)

 

[ianganderton]

Attached are irradiance tables for Birmingham (arbitrary UK location)

To use these numbers you can litterbugs just multiply your panel wattage by the number to estimate daily power generation from your array.

I’ve included 2 tables to show the difference between flat and tilted.

The optimal winter angle for panels would be 67 deg from horizontal. This doubles power output but is still very poor in reality.

I’m going to take a guess From the title that this vehicle will be used in motor racing paddocks.

While doing a power audit does seem initially challenging it’s also not so hard one you start

Do you need a fridge (tends to be one of the big ticket power draws). If so what size.
How many people will you have Using the truck over a weekend?
Are you planning on using a heater? Diesel or propane?
Microwave? Kettle? Toaster? Propane stovetop or oven?
Lighting? Will you need external work shop lighting under an awning? If so how much?
Device charging? Laptops? How many?
Power tool chargers? Compressor?
Tv/entertainment system?

This can all easily be estimated at a planning stage and facilitated good system design. Just having an idea of 240v appliances and their wattage will enable correct inverter specification and battery voltage

My guess is that this set up will need a generator for additional power so I would be planning that into the system design.

I think the titling panels will cause wind problems. UK weather is not very settled.

I think maximising flat panels in the roof and packing a inverter generator for topping up when needed will be the best, most efficient and robust option.

 

[Hedges]

Do those irradiance tables include average local weather? Or just sun angle and hours of daylight?
Shortest month December shows 1.09, so a 100W (STC) panel might actually produce around 109 Wh/day because it is cold.

 

[ianganderton]

Do those irradiance tables include average local weather? Or just sun angle and hours of daylight?
Shortest month December shows 1.09, so a 100W (STC) panel might actually produce around 109 Wh/day because it is cold.

They include weather

UK doesn’t get particularly cold temp wise because of relatively warm seas (Gulf Stream). Snow is occasional. Rain in normal

 

[MezzBatt]

WOW....!!!! Some major input here fella's. I'm starting to get a feeling that flat will be ok. The idea (post covid19) is to spend winters out of the UK away from the rancid weather we get, somewhere much warmer like Portugal or Greece. Mains hook up is not what i want to be reliant upon more so 'as and when'.
I think I will max out the roof space with panels and work backwards as what 'ianganderton' said. I'll get this info shortly and let you kind folk know what the total wattage is.
@George, yes i can build an automated tilting system myself without paying someone thousands, I've been building custom bikes and all manner of things over the decades so working with ally angle and hinges is a piece of cake....

So, lets assume I'll go with 'Flat' ok, My next decision would be whether to use a beefy inverter/charger or MPPT + SCC's + separate inverter. This is where I start going round in circles again and again. Would it help if i make a decision now to stick with 230v domestic appliances as much as possible or will that decision come after I've worked out the array wattage potential....????

One thing I do know is that I really do appreciate all the help on here. I bet folk have all too often got it wrong by just zooming ahead and building their version of the ideal setup. I'm open to all the advice given, i normally read every ones posts several times (apart from George, only got time for one read so i pay attention...!!!).

Thanks again and keep posting, I will arrive at what's best for my application for sure......

 

[ianganderton]

WOW....!!!! Some major input here fella's. I'm starting to get a feeling that flat will be ok. The idea (post covid19) is to spend winters out of the UK away from the rancid weather we get, somewhere much warmer like Portugal or Greece. Mains hook up is not what i want to be reliant upon more so 'as and when'.
I think I will max out the roof space with panels and work backwards as what 'ianganderton' said. I'll get this info shortly and let you kind folk know what the total wattage is.
@George, yes i can build an automated tilting system myself without paying someone thousands, I've been building custom bikes and all manner of things over the decades so working with ally angle and hinges is a piece of cake....

So, lets assume I'll go with 'Flat' ok, My next decision would be whether to use a beefy inverter/charger or MPPT + SCC's + separate inverter. This is where I start going round in circles again and again. Would it help if i make a decision now to stick with 230v domestic appliances as much as possible or will that decision come after I've worked out the array wattage potential....????

One thing I do know is that I really do appreciate all the help on here. I bet folk have all too often got it wrong by just zooming ahead and building their version of the ideal setup. I'm open to all the advice given, i normally read every ones posts several times (apart from George, only got time for one read so i pay attention...!!!).

Thanks again and keep posting, I will arrive at what's best for my application for sure......

You need to do the power audit. Until you do that you won’t see the difference the different decisions make at this point

Living off grid successfully is about optimising your limited resources. Each time you convert electricity from one type to another you loose some. In an inverter it will be around 15%, sometimes less, sometimes more

You need to work out how many watts (Both AC and DC) you want to run at anyone time and for how long

If you don’t have an understanding of your daily watts used and your peak watts you don’t have the information to make the next decisions.

 

[ianganderton]

Could you elaborate on what decisions they would be in this application?

Op will max out his generation space, that's a given for anything. Next would be battery size. That's probably going to be a space and Cost consideration but even if one goes larger, it's only useful ( as I see it) to a point where if you don't have the charging capacity, it's detrimental in fact. Could be better if using the vehicle charing system but that's kind of seperate to the solar issue in my mind.

The other thing would be the inverter. If one went 2 or 3 KW, what's the difference other than a bit of cost? 3 kw will be no harder or expensive to wire than a 2 and give you some margin. I can't begin to think what you coudn't do in this type of setup with 3 Kw. It would power anything likley to be in the setup such as microwave, Fridge and lights and all together., Normal household Circuit here and I believe in the UK ( and NZ) is only 3600W. That's for the whole circuit not a single outlet. Go 4 Kw if one likes and you would have full mains circuit output and power to spare. The power audit may tell you if you need that or 3 kw will do as I would highly suspect even if a little power management had to be employed.

What do you see as the main advantages and affect decisions of the power audit?


I have not seen an inverter in the last 20 years that had more than 10% inefficiency and that's including a lot of crappy Chinese ones. Grid ties ATM and for some time have been closer to 97% efficient, 3 % inefficient.
I'll grant you I question that. For 5KW inverters to get as hot as they do and generate the ongoing heat they put out, the 3% going to heat does not seem to add up to the heat generated I see.

I get where you are coming from completely and you are correct. The thing is to me, far as the solar goes it's pretty much a fixed Thing. It's going to generate so much power and that's it. More chance than not it won't be enough but unless one is clueless and adds in unnecessary loads, less likely here due to space considerations for one thing, The the loads are what they are.

If the solar isn't up to it, then you either have to add extra like a ground mount off the rig or you have to go to a generator or the vehicles power supply to make up the short fall.
I don't see it as practical to just cutting out appliances or loads but I would be interested to hear what you specifically see are the biggest benefits and the variables in the decisions you speak of.
I'm sure the OP would as well! :0)

I’m answering off my phone so it’s difficult to see the questions easily

Battery size (Watts) is based around power use age and typically involves deciding how many days of autonomy without charge is desired. Understanding this relationship makes for good decision making on probably the most expensive single item.

Understanding the amount of power different appliances use is really useful for deciding how to power them. Efficient 12v DC appliances are very common making them cheaper. 24V less so, 48v don’t really exist outside of specialist units so deciding battery voltage helps when looking at this. The size of the inverter and likely maximum draw helps paint this picture. I’m planning on having a kettle, microwave and toaster in my van as it’s the most efficient way to have the breakfast I like. This is quite a short sharp power draw.

For the op with e title race truck there could be all sorts of tools that he may want to power so it helps to have an understanding of what their power requirements are.

All of these things add up to a much better understanding of the system needed. Having this understanding is the cheapest way to save time and money because it costs nothing and results in a system that will fullfil needs rather than just a guess

 

[ianganderton]

There is a really good article on real world inverter efficiency. The marine guy did some testing. It certainly wasn’t the advertised. It makes a particularly big difference in the decisions around fridges. Loads of stories of people opting for a cheap AC fridge only to be changing it out because it chews through the power

 

[JoeHam]

So what I learned today is that on an overcast winter day panels should be flat for maximum output?

Can someone elaborate on that or point me to a reference?

 

[Hedges]

Here you go:

Increasing the solar photovoltaic energy capture on sunny and cloudy days | Request PDF

Request PDF | Increasing the solar photovoltaic energy capture on sunny and cloudy days | This report analyzes an extensive set of measurements of the solar irradiance made using four identical solar arrays and associated solar sensors... | Find, read and cite all the research you need on...

www.researchgate.net

"During cloudy periods, we found that an H configuration increased the solar energy capture by nearly 40% compared to a DTS configuration during the same period ..." ("DTS" meaning direct toward sun)

And it actually makes some sense. With the sun at an oblique angle, the whole cloud cover becomes a diffuse illumination source.
Straight up would then get light from all directions, while tilted would have some directions seeing the darker ground.

 

[MezzBatt]

Again many thanks....
So, I think George kind of summed it up there in his last sentence .......

"Flat is the most favorable for both the best ( summer) and worst ( cloudy) Conditions as ironic as that is"

This has swayed my decision to go FLAT (not flat earth just flat solar....!!!!)

 

[MezzBatt]

There is a really good article on real world inverter efficiency. The marine guy did some testing. It certainly wasn’t the advertised. It makes a particularly big difference in the decisions around fridges. Loads of stories of people opting for a cheap AC fridge only to be changing it out because it chews through the power

This is my quandry and I've read on lesser forums that aren't specialised in this topic saying "yeah mate, no problem, I run me fridge n TV all day mate no bother" etc etc !!! I need to get this bang on right first time, I'm very lucky as in I have room for a decent budget because of my current job but this could change so I'm going to get it built sooner that later.....
The title 'Racetruck' is from it's previous existance, sure I'm putting my bikes in the back and at best the biggest power demand from the garage will be a small air compressor capable of doing the trucks tyres if need be.

From what I have learnt so far if I decide to use 230v domestic appliances a 48v battery would be best and the biggest Inverter OR go inverter/charger (again dependant on solar array wattage yes....?????). I have an onboard generator but yet to look it over for its output and general condition which could be used. Georges idea of extra panels being used by some quirky setup appeals to me so may look at that idea....

 

[ianganderton]

This is my quandry and I've read on lesser forums that aren't specialised in this topic saying "yeah mate, no problem, I run me fridge n TV all day mate no bother" etc etc !!! I need to get this bang on right first time, I'm very lucky as in I have room for a decent budget because of my current job but this could change so I'm going to get it built sooner that later.....
The title 'Racetruck' is from it's previous existance, sure I'm putting my bikes in the back and at best the biggest power demand from the garage will be a small air compressor capable of doing the trucks tyres if need be.

From what I have learnt so far if I decide to use 230v domestic appliances a 48v battery would be best and the biggest Inverter OR go inverter/charger (again dependant on solar array wattage yes....?????). I have an onboard generator but yet to look it over for its output and general condition which could be used. Georges idea of extra panels being used by some quirky setup appeals to me so may look at that idea....

Sorry I forgot to dig out the link to the article

A Look at Inverter Inefficiencies - Marine How To

AC vs. DC Tested on a 12 Volt / 120 Volt TV For this brief article I wanted to test the total system inefficiency of using inverters when powering an LCD TV. It is stated by many companies that

marinehowto.com

To my mind the correct process to correctly design an off grid system is

1 - design the layout of your van/cabin. Include roof vents etc. kitchen options including power for cooking, heating options, insulation, lighting, required power outlets.

2 - understand desired power use (power audit) inc average daily watts, peak watts and peak AC.

3 - size battery based on average daily watts and number of days autonomy

4 - size solar array based on average daily power use & solar irradiance availability

5 - design electrical system based on solar array size and peak AC requirements.

At each stage you are likely to find details that may affect other factors requiring re evaluation. Eg maybe there is not enough room for the solar requirements for charging needs or the cost of a battery is too much.

Optimising power use is key with any off grid system. Using less power is the best way to save cash. Appliances that might have a low price tag may cost a lot if they are inefficient (fridges are a good example)

Random thoughts:

Some inverters and SSC especially the all in ones can have noisy fans which is particularly noticeable in an enclosed van.

Solar is the most efficient way to charge batteries but only if there is sun. The UK doesn’t have the best weather for winter sun. Southern Europe absolutely does!!

Absorption fridges are a lot quieter than other options but good DC compressor fridges are the most efficient and powerful.

There are some problems with alternator charging. It uses quite a lot of energy (fuel) which is often over looked but on the other hand is a great way of charging batteries if driving regularly. Charging on tick over is inefficient.

I thing diesel heaters offer the most efficient option for off grid space heating.

 

[schmism]

Ummm, The truck is going to be 24V I take it. What voltage are the panels you have? My guess on that size will be about 37-39V Open circuit and 30-32 Vmp Either way you will need a Buck Converter ramp the voltage up to around 52V where the batteries will want to float from either of those sources.

Nope, absolutely will not need a converter on the panel side. You keep putting the panels in series until your at 80v or 100v (150v even) and then the MPPT SCC converts that 80-150v down to the battery voltage used on the system. ("24v" = 28v ish and "48v" being 56v ish)

Granted there is some trade offs for series vs parrallel panels for partially shaded but for large "fixed" panels they should be in the high 20's to 30's volts.

All in ones for this size build would be my first choice. Placed in a lower cargo/equipment bay the fan noise would not be noticeable.

 

[Hedges]

You could not then charge from the vehicles electrical system when travelling unless you put in switches to take the batteries from series to 2 parelled pairs, More complication and expense and, when charging you couldn't run the inverter which would be a drawback in my book.

To make a dual battery isolator, I tacked 3 wires on the alternator and pulled them out to diodes.

If you pulled out the 3 phases from the alternator and put them through transformers, you could boost to whatever voltage you wanted and rectify.
Power handling would be a function of core size and frequency.

 

[JoeHam]

Here you go:

Increasing the solar photovoltaic energy capture on sunny and cloudy days | Request PDF

Request PDF | Increasing the solar photovoltaic energy capture on sunny and cloudy days | This report analyzes an extensive set of measurements of the solar irradiance made using four identical solar arrays and associated solar sensors... | Find, read and cite all the research you need on...

www.researchgate.net

"During cloudy periods, we found that an H configuration increased the solar energy capture by nearly 40% compared to a DTS configuration during the same period ..." ("DTS" meaning direct toward sun)

And it actually makes some sense. With the sun at an oblique angle, the whole cloud cover becomes a diffuse illumination source.
Straight up would then get light from all directions, while tilted would have some directions seeing the darker ground.

Thanks!

I imagined the clouds would act like a diffuser which altered the angle of incidence of sunlight but had no idea it would make such a difference.

 

[schmism]

Depending on the inverter may also limit the option of charging from the generator. 48V AC battery chargers would not be cheap and may not be very compact either . A hybrid alt would be OK but still leaves more complication with onboard electrical Charging.

I'd want all the options I could get, solar, Vehicle and Generator for charging and keep it the most straight forward with the minimal potential failure points.

I'm not advocating for 48v system specifically, however I could take that side of the debate for the moment.

1) If you chose a all-in-one (ill use growatt as an example) it includes its own battery charger from grid power. So no need to buy an AC battery charger.

2) Per other threads on RV builds, the goto answer for "how do i have shore power and generator power?" is a transfer switch as there virtually no reason to run both at the same time.

3)alternator charging needs to be current limited as to not fry the ICE alternator. Typically this is accomplished by useing a buck converter that is limited to say 20-40 amps which is fairly typical.

If you want to look at the 24v version.

1) is the same
2) is the same
3) you still cant connect the 24v "house" battery directly to the ICE alternator per previous comment about burning it up. So you still need a limiting device between the 2 systems.