12v Solar,.Generator, inverter setup

[Monroelkjr]

New guy here trying to setup my RV for off grid boondocking.

Here is what I have:

5 Sharp 123w panels 21v 7.3a
4 Kyrocia 51w panels 21v 3.1a

1 Tristar TS-60 PWM charge controller
1 20a solar PWM charge controller

Onboard Onan Emerald ! 4kw generator
Honda eu1000i generator

Aims 1500w inverter/charger with transfer switch
Aims 3000w inverter charger with transfer switch

The RV alternator also charges the batteries while underway

I also have a morningstar RD-1 Relay device with 4 channels

8 Trojan 6v 105 golf cart battery bank 12v.

Loads:

1 mini split A/C unit 5000btu (homemade from window unit) 450w 4a draw
Colman 15000btu RV air conditioner unsure of watts and likely a 10 11 amp draw.
RV microwave
Home mini tower with 750w supply
42" Plasma TV
70's Pioneer quadraphonic receiver (aprox 100w audio power not sure on the 110v input power)

I run other stuff but this is the main loads and I can not use the Microwave and the AC at the same time. I can run any of the other stuff in combination with either the AC or the Microwave.

Here is what I want to do:

Modify the Honda eu1000i for electric start, so I can use it to supply current to the battery bank when I run the small 450w AC unit at night once the bank falls to 60% Using the Aims 1500w inverter/charger and the RD-1 relay control.

Because I live in Texas mostly and it gets very hot and humid.

If I'm running the whole RV I want to do the same using the Onan and the Aims 3000w inverter charger.

Because I can run the generators I use the aprox 800w solar and aprox 800ah battery bank to supplement them.

There is a mismatch in current on the PV panels so I'm not sure if I can use the one tristar to control them all or I should use the tristar only on the bigger panels and the other little controller on the smaller panels?

There really is no room on the roof for more panels.

Any thoughts?

Monroe

[Mike90250]

Honestly, I'd say scrap the solar and run off the honda 1000. If you are rigged up to charge while driving, and you need to run the AC off the genset at night, what does the solar do, except force you to park in the full midday sun ?
900W of panels seems like a lot, till you find out that laid flat on the roof (or drill 30+ holes to mount them with) you might get 50% of nameplate wattage. To get 400w of power @ 12V is 33A, which your alternator can easily do.
4 batteries in parallel (2Sx4P) needs to be wired on the diagonal - see http://www.smartgauge.co.uk/batt_con.html as to why.

So, that's my opinion.

[Monroelkjr]

Yeah I get what your saying. I do have this stuff so I thought I'd use it. I need to convert the eu1000i to electric start anyways.

I do have this little motorcycle trailer (I sometimes pull my harley in) I could park it in the sun while the RV is in the shade and I was thinking about putting panels on it. I also have 2 250w panels and 6 SMA micro inverters and a com box for them. But that was for a gridtie system I was planning for my shop.

I guess I could get one more of those panels and have 750w on the trailer and put another bank in there. Run a inverter charger and send the AC output to the RV via the power connector and a heavy extension cord I have.

So I would have to buy 1 more panel and another aims 3000w inverter as well as another $1000 in batteries so that's another $2000-3000 if I buy another eu1000i investment.

Fuel is expensive because I live fulltime in the RV.

If I can run the little AC for 3 hours before the gen kicks in that saves me having to go back to town and interrupt my enjoyment. I can stay a month in the boondocks without any other reason to return other than fuel.

Monroe

[Mike90250]

This is called planning, what you need, what you can live with, and making reasonable estimates of how much trouble going solar is worth. Holes in the roof for mounting? panels on a trailer

[Monroelkjr]

Well it is part planning part doing what you can with what you've got!

Thanks for getting me thinking about shade. It does not make much sense to sit in the sun and try to run A/C if you do not have too. The trailer Idea keeps making more and more sense. I'm in the process right now of installing a new roof on the RV which brought this all up.

I sometimes spend a couple months in the high desert in Mojave and there is no shade at all there. However I'm considering a swamp cooler for one of my roof vents to help handle that. I will not pay $700 for a simple cooler like that I can fabricate one in my machine shop instead.

I can change the tilt on the panels with the tongue of the trailer. If I could just fit 6 panels on the trailer I could get 1.5kw worth of panels on it and carry another 800lbs of batteries.

Having an AC line running from the trailer helps reduce losses.

This is getting really close to the max weight of the trailer now with 100lb propane tank the Harley a few tools and the battery bank.

Right now this is just thoughts/planning on the trailer.

Monroe

[Mike90250]

Is there a reason to limit the trailer battery to 12V ? 24V or 48V reduces loss a few %, you are running 120VAC to the RV, not 12V. When you move to 24 48V the gear is also more efficient (if bought wisely) Everything centers on efficiency, which translates to less battery, less solar. And there are the trade offs, big heavy batteries that get replaced every 5 years, or less batteries and a small generator. DIY mini-split misses the true mini-split point, which is an efficient variable speed compressor with very low starting surge, they consume 1/4 of what you built. And cost 10x as much.

[Monroelkjr]

Yes the bank on the trailer should be 24 or 48v I agree. The trailer would be all new stuff except for the 2 panels I already have.

As for the mini split there are other reasons I did that. One was to see if I could. The other was 410w so it's not as efficient as an inverter compressor I don't care it's not about seeing how much money you can spend (cost me about $300 and about 24hr time). It's about what you can do.

I could spend unlimited money on a system I could keep changing.

The goal here is to enjoy nature a month at a time.

I just retired at 55 and I want to see nature

Anything that cost over $500 to me is a serious investment. No matter how much money is in the bank.

I'm an old Electronic Engineer/Fabricator/Machinist that likes to build rockets for fun. My current hobby is building a turbopump for a small orbital atempt. (Team Prometheus)

So you can back off a step please? I'm satisfied with what I've planned for the RV. I appreciate the thought of shade which sparked the trailer idea. But your tone seems a bit much. What gives there?

Monroe

[Mike90250]

No tone intended. Just conveying info. I'm not selling you anything. Just letting you know what's there and whats been done before.

I too, am a retired spacecraft electronics engineer. Last job was the redundant power supply for the JWST internal instrumentation and health monitoring.

[Monroelkjr]

Hey that's interesting! We have something in common then. Yeah, perhaps I've gotten a bit sensitive to the internet. So many people seem to know everything these days and have little to no real life experience. I argue with a lot of Phd's that have the problem of knowing all that book learning but very little practical experience. What I mean by that is actually doing the work.

There is one problem with all this stuff running in an RV I have come to realize.

We need a multiple source controller that can take DC input from 2 or more sources and properly charge a battery bank.

This idea that it's ok for multiple sources to fight because there are multiple controllers is absurd!

What I'm talking about is one controller being in bulk mode and another being in asorb, float ect...

I don't like the idea of a converter running off an inverter either while running off the battery bank which is what you might be doing. I realized this was happening in my RV. You have to bypass that converter while the inverter is running other wise your trying to charge the battery with the battery.

I'm currently pondering a solution for the controller issue.

Monroe

[Mike90250]

Batteries can charge from multiple sources. I've got the voltages and times set very close to identical on both my Morningstar and Classic controllers, and they work well together, and both enter float within about 10 minutes of each other. When you size the system right, you will be running the generator in the poorest sun month, and barely making into float for other winter months, then in summer with longer days, have time in float, but your HVAC may eat a lot of that up. Increasing interior thermal mass (tough in mobile) will help.
Bounce ideas around before you buy gear.
Midnight classic has EZ wifi remote control from windows or android, but it also has 3 noisy cooling fans. Most other charge controllers can be reprogrammed, but not easily remote controlled.

[Sunking]

5 Sharp 123w panels 21v 7.3a
4 Kyrocia 51w panels 21v 3.1a

1 Tristar TS-60 PWM charge controller
1 20a solar PWM charge controller

Onboard Onan Emerald ! 4kw generator
Honda eu1000i generator

Aims 1500w inverter/charger with transfer switch
Aims 3000w inverter charger with transfer switch

The RV alternator also charges the batteries while underway

8 Trojan 6v 105 golf cart battery bank 12v.

Loads:

1 mini split A/C unit 5000btu (homemade from window unit) 450w 4a draw
Colman 15000btu RV air conditioner unsure of watts and likely a 10 11 amp draw.
RV microwave
Home mini tower with 750w supply
42" Plasma TV
70's Pioneer quadraphonic receiver (aprox 100w audio power not sure on the 110v input power)

Well here is a peer review from a retired EE who does this for a living, and I do not pull any punches.

In a nutshell nothing you have was ever thought out or made to work with each other. Lets start with your panels and controllers. First mistake was buying and using PWM Controllers, and using prime number of panels. By doing this you are forced to wire all you panels in parallel which is going to cost you a lot of money in a lot of over sized wire and requires you to use combiners and fuses. There is no way to use 5 panels and operate on anything other than 12 volts.

So you have roughly 800 watts of panels. When coupled with wiring them in parallel with a PWM controller on an RV you are down to 500 watts, and at best bein gon an RV you might make 1500 watt hours in a day if you are lucky. If you do some simple math you will find out you cannot run anything you want like you want to use it. Example that AV using 450 watts, afdter 3 hours you have already used everything the panels might or might not be able to generate in a day. Forget anything else, you do not have the capacity to support it.

Lets move on to the batteries. 8 x 6 volts x 225 AH batteries have a capacity of 10,800 watt hours of capacity. Configured at 12 volts is 900 AH. Minimum charge current requirement for those batteries are 90 amps. Now with a PWM controller would require 1600 watts of panels and two controllers. With MPPT would require 1000 watts of panels. Either way you do not have enough panel wattage to support what you have.

Move onto Inverters. Your Trojan batteries are a good choice because they can deliver some higher current levels without a lot of voltage loss. About C/4 or for your 900 AH would be 225 amps. On paper could support a 2000 watt Inverter. but that involves a lot of fire risk running that much current.

So you really need to stop and think about what you are doing. So far your plan is to fail, go dark, and high risk of a fire.

[Sunking]

Hey that's interesting! We have something in common then. Yeah, perhaps I've gotten a bit sensitive to the internet. So many people seem to know everything these days and have little to no real life experience. I argue with a lot of Phd's that have the problem of knowing all that book learning but very little practical experience. What I mean by that is actually doing the work.

There is one problem with all this stuff running in an RV I have come to realize.

We need a multiple source controller that can take DC input from 2 or more sources and properly charge a battery bank.

This idea that it's ok for multiple sources to fight because there are multiple controllers is absurd!

What I'm talking about is one controller being in bulk mode and another being in asorb, float ect...

I don't like the idea of a converter running off an inverter either while running off the battery bank which is what you might be doing. I realized this was happening in my RV. You have to bypass that converter while the inverter is running other wise your trying to charge the battery with the battery.

I'm currently pondering a solution for the controller issue.

This is all a non issue. Again failing to plan is a plan to fail.

Fist there is no problem charging from multiple sources. Assuming it is arranged properly. Example the stiffest source will provide the charging like the vehicle alternator. With the engine runing with say a 100 amp alternator, the alternator will provide all the power. The soft sources like solar will see it as the batteries are charged up and turn itself off. No problem, that is what is suppose to happen.

Secondly they make Inverters for RV with built in chargers and ATS switch. So when you plug into shore power or run a generator , it turns off the Inverter, and turns on the built in charger. All power now comes from shore power or generator. You have somehow built a loop using a converter.

If this were me and you were my client I would recommend you chunk the solar in the nearest garbage can. Determine your daily power needs in terms of watt hours, get rid of all the high power consuming items like plasma TV, desktop with with 750 watt supply, and all the other highly inefficient stuff you have. If you must have toys and luxuries for camping, replace them with efficient devices like LED TV and a Notebook computer. Get yourself a good Inverter made for an RV with built-in Battery Charger.

I would then look and see what kind of Battery Isolator you have to make sure it is Electronic Type with built-in Voltage regulator to control the Alternator. Instruct you when not driving daily to use the ONAN generator to charge the batteries and run the air conditioning because there is no way your batteries can handle that. If you refused to take the advice, I would send you packing to a DIY forum because I want no part of a plan to fail.

[Monroelkjr]

Lol Sunking you are a real live a$$ are you not? I planed on exactly 3 hrs run time on the A/C with this set up before the generator kicks in to charge the batteries. 3hrs on solar is better than none.

#2 I did not buy any of these panels or the controllers I inherited them and as I stated this solar is just to supplement the generator not replace it.

#3 PWM is not that bad and I can prove that with the math. So many nut cases believe PWM is worthless it's not. It's certainly better than nothing.

#4 If you plug the inverter into the shore power connector you sure as hell will get a charging loop going even if you have an ATS in other words your a loud mouth know it all just as I mentioned.

#5 There is a problem charging from multiple controllers and multiple sources if you don't see that then well. Your not a very good Electrical Engineer.

I have found a company that at least has a clue with their FOLLOW ME controller networking. (I do believe you want need to be corrected on who they are)

Setting controllers to same voltages is not a proper solution as I have seen said it still can bunch up.

Sure if I wanted to spend a ton of cash I could design an ultimate system. Solar is not just a rich mans game fella. Sometimes you make do with what ya got.

Now if anyone has any suggestion on how to make the system I have function better WITHOUT spending much money I'm all ears.

The solar on the trailer is a different deal. That I am buying the components for and it is in the planning stage.

I also am not going to trash what I have just because you don't particularly like what I have to work with.

Monroe

[Sunking]

#3 PWM is not that bad and I can prove that with the math. So many nut cases believe PWM is worthless it's not. It's certainly better than nothing.

Then you do not know anything about the math or using make believe math.

[Mike90250]

Nearly all the big boy brands have controllers that will network and assign master/minion devices. Since you are going with Solar and AC from grid/trailer you should look at Schneider (Xantrex) gear, which has good networking from inverter, generator, Solar CC, load sensing.