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Solar Goal Adequate?

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Hello, everyone!

Pretty new to the Class A lifestyle (2017 Newmar Ventana LE), I had the dealer install a 160 Watt Zamp Solar Deluxe kit, anticipating I may have a potential need and desire to increase capacity. It was important that the Zamp panels make it easy to add a panel or two with simply a plug-in feature, requiring minimal effort to do so at minimal cost (short of self-installation).

While I don't have specific plans to boondock extensively, I also expect I will want to seek hideaways and places absent shore power, so that I may also enjoy the benefit of dry camping for 1-2 weeks at a time, and perhayps longer. After much research, and tapping the experience of the technicians who initially installed the first panel, I've chosen to add two additional 160 Watt panels (for a total of 480 Watts, producing 8.7 Amps each (total 26.1 Amps), and have a 30A Controller.

i also have a fridge that can run electric or gas, a house battery bank of 4-6 Volt batteries, 2 - 15M Inverters, and plan to be judicious with my TV & microwave usage. 

Since the original dealer is 500 miles away, I've ordered the panels from Amazon, and I'm planning to have a local Zamp dealer install them, which saves me about $400, when compared to having the original dealer sell and install each panel.

Based on the above information, would you conclude that my solution should, under most circumstances, work well for my anticipated needs? If not, what would you recommend?

Thanks for your input and advice - it's much appreciated!

Michael

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Seems that most of your ducks are in a straight row. My concern probably would be storage capacity, you have 4 6 volt batteries, unknown to the rest of us what size in total amp hours. The ability to recharge them sounds pretty good, but trying to figure run time can be deceiving. The sun is only available 8 to 12 hours per day in most areas, and for that reason, I would also include in my calculations my battery bank requirements to figure how long will I be able to run lights and appliances during off hours also. You may want to add some batteries to your list also. Good luck with the project.

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I presume your fridge is an rv type so you don't want to use it on electric because of the high amp draw compared to a household type.  If you want to dry camp for 1 to 2 weeks at a time I would suggest you do a dry run in your driveway.  Run everything you would dry camping, tvs, lights, furness, inverter, anything that draws current from the batteries.  after the first 24 hours see where the battery charge is. If you are wanting to rely on solar only don't start the gen.  If you need to reduce the amp draw, try unplugging your tvs and dvd player and any other electronics as they draw almost as much current when turned off as when on.  If you can't maintain battery voltage and have to use the gen then you will have to increase you solar wattage if you don't want to run the gen.

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You should be able to buy solar panels for about $1.00/watt or less.  I just added a 250 watt panel for $250.

Once your first panel is installed it should cost very little for additional installation, all you do is connect the new panels to the existing, no wires to run to the batteries, unless the initial installer used under size wire.  

Are you connecting the panels in series or parallel?  Is your controller MPPT? You might want to insatall a battery monitor to see how your  level of charge and others info. 

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I have Zamp Solar (Expansion) panels, which are designed to plug into one another as they're added. What's MPPT? I have a 30A controller, and the total output of all 3 (160W) panels is 26.1 amps. In addition to a factory installed voltmeter (I admit this probably isn't as accurate as a purist would require), the controller for the solar also has a voltmeter and both seem to be in tune with he other. Been told an ammeter is worthwhile, to show power going out and coming in, but am not technically savvy as an electrician to install...

Kaypsmith, I hear you... Can't tell you yet if there's room for two more 6-V batteries, as my parking needs at home make opening that bay door impossible to check batteries until I move the rig, however, that will happen in a few days, and will check then to determine amp hours available, and, if there's room to add more reserve...

I hadn't considered unplugging electronics that aren't running, but it makes sense that things like TV and audio "at the ready" would draw power... Fridge is not a residential unit, runs on propane OR internal power...

This brings up another question, though... Internal lights are all LED's, but wonder if a stand-alone, battery operated lamp would be prudent at appropriate times. ?

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On 4/4/2018 at 0:34 PM, kaypsmith said:

Seems that most of your ducks are in a straight row. My concern probably would be storage capacity, you have 4 6 volt batteries, unknown to the rest of us what size in total amp hours. The ability to recharge them sounds pretty good, but trying to figure run time can be deceiving. The sun is only available 8 to 12 hours per day in most areas, and for that reason, I would also include in my calculations my battery bank requirements to figure how long will I be able to run lights and appliances during off hours also. You may want to add some batteries to your list also. Good luck with the project.

Here's an update -

i checked the house battery bank, found this: 115 min @75 amps... 225 Ah @20 Hr on each label (?), 4-6V batteries, no apparent room here to add two more, and not sure where I'd put them, even if it were prudent to do so. Just installed 2-160W panels, and now have total of 480 watts, producing max of 26.1 amps, with a 30A controller... 

Comments?

 

 

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Since you are working with 12 volts to deplete the batteries, and also to charge them, it takes 2 6 volt batteries to equal 12, this means that if your batteries are fully charged, then 2 6 volt  = 12, then for each set of 2, you have approximately 115 minutes of draw at 75 amps. Now since you have 4 6 volts, you can now multiply those numbers by two, 115 X 2 = 230 minutes at 75 amps, or 75 X2= 150 amps for 115 minutes. Now of course if you figure that you might be drawing 30 amps, then you can now multiply 2.5X230= 575 minutes at 30 amps, then of course divide 575 by 60 (number of minutes in an hour)= 9.58 hours. This is just some basic math to give an example of how you can figure some of your questions? More batteries do not need to be adjacent to the existing ones, they could be placed in almost any location, as long as you use adequate size cable to join them. I have a couple of friends that boon dock frequently, we used a rack on the back of their coaches to place extra batteries when needed, just another idea if anyone wants to go to that extreme, and these guys did. As DD69 suggest you can use your setup in the driveway, turn on only what you think that you need to run, then monitor how long you can go without another source of electricity.

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MPPT controller maximizes your ouput for the battery, and will provide close to 100% of your panel output. With a regular controller you may get only about 70% . Complicated, read it here: https://www.solar-electric.com/learning-center/batteries-and-charging/mppt-solar-charge-controllers.html

All panels plug together very easy, that is just sales hype by Zamp. 

Your 4 batteries will give you about 200 amp hours, but to prolong battery life you want to use up to 50% or 100 AH. Add up all your devices that use 12volts and see how close it comes to 100 AH. Unless you have some unusual power requirement you should easily last overnight on batteries and will be able to recharge to 100% by noon the next day, with good sunshine. 

You should add a battery monitor, it will tell how much you are using, how much going back in, state of charge and other things. A simple one is Vitron BMV 700, about $150,

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The first thing you should have done is visit https://handybobsolar.wordpress.com/ for your lessons on solar 101/ 102/103 for what really works and what does not. For how to run you system efficiently and to get the maximum from it. A meter is vital to you knowing what is in you batteries for use and what is going into them during recharging for starters. You need to know almost as much as the installers do because many of them are selling no charge systems because they do not know as much as they think they do.

 

B

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I looked at the information in the preceding email. There is a lot there and a lot that does not pertain to us in the RV world. There is plenty to clutter your perception. Some of the gear there and recommended, is questionable in terms of the charging cycle according to Bob's site. Bob is a retired electrical engineer that sells little with no fiducary interest and gives away the information so we can make an informed decision. This site is selling componetry and subsequenly steers the conversation in a benificial direction. The first part of the equasion is to read and understand the "charging puzzle". Then you can move on from there.

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I understand the idea of solar panels on the roof of an RV owned by someone that enjoys dry camping (boondocking to greenhorns). However, I recently read an article about the heavy metals (toxic) in solar panels. Have thought that they would be a problem.  What to do with them when the panels complete their life cycle?  There is a nationwide craze of solar panel installation. Re: California will require them on new buildings. Where will all of this "bad stuff" go?

We did a lot of dry camping with our first coach. Various federal campgrounds that offered almost nothing but a water source ( if that). were a favorite. Wish that we had a 2000 Watt Inverter Honda generator back then. They are remarkably quiet and fuel efficient.

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