Solar Panels April 19, 2006, 11:22:01 pm Yahoo Message Number: 65647I have a couple of questions re: solar panels.1) If you have multiple panels, do they all have to be the same size i.e., watts, if you decide to add additional panels? 2) If you add panels, can they be from a different manufacturer? 3) Is there some rule of thumb regarding the ratio of batteries to watts of the solar panel?Someday I may finally figure out this stuff.Kathi
Re: Solar Panels Reply #1 – April 19, 2006, 11:46:18 pm Yahoo Message Number: 65649Quote I have a couple of questions re: solar panels.1) If you have multiple panels, do they all have to be the same size i.e., watts, if you decide to add additional panels? 2) If you add panels, can they be from a different manufacturer? 3) Is there some rule of thumb regarding the ratio of batteries to watts of the solar panel?Someday I may finally figure out this stuff.Kathi \\ There are a number of very informative sites on the internet, written for the layman to understand. I bet someone will direct to one or more of them.You can mix and match solar cells to a degree, though this isn't recommended by most manufacturers. You should not mix panels with different voltage outputs, as this will decrease effeciency overall. Think of the total wattage of your array as representing the amount of energy that you can eek out of the sun. If you have a large array, and a smaller battery bank, one many days your batteries may be fully charged shortly after breakfast! The rest of their daily output will go to waste. A big solar array may still generate substantial power when it's cloudy or when the winter sun is low in the sky.A larger battery bank gives you a place to store all this energy. It will see you through long nights and maybe several cloudy days in a row. So you can see, it really depends on how you'll be using your LD, how much electricity you'll be using, when you'll be using it (i.e. if you use lots during the day while the solar panels are working, then you might get away with a smaller battery bank).all the best,bumper Yonder (400 watts solar, 450 amp hour battery, 2000 watt Prosine inverter)
Re: Solar Panels Reply #2 – April 20, 2006, 01:33:47 am Yahoo Message Number: 65656Quote from: Kathi R."I have a couple of questions re: solar panels.1) If you have multiple panels, do they all have to be the same size i.e., watts, if you decide to add additional panels? 2) If you add panels, can they be from a different manufacturer? 3) Is there some rule of thumb regarding the ratio of batteries to watts of the solar panel?Someday I may finally figure out this stuff.Kathi \\ Bumper is right on all counts but I will add a couple of items. If you are using one of the Heliotope RV-30 controllers LD used in the past, you can add panels from different manufactures or different models from the same manufacturer but they should all have the same max power voltage rating. When this controller connects the panels to the batteries, it pulls their voltage low enough that the details of each panel's volt-ampere curve don't matter very much.If you are using a so called "boost controller" (e.g., a Blue Sky Solar Boost 2000E or an AM Solar HPV-22) it is probably a pretty good idea to use panels with the same cell count, with the same technology, from the same manufacturer. Here the details of each panel's volt-ampere curve matter and to get the best performance from the array, all of the panels need to have a similar curve. It isn't that anything bad happens with mismatched panels, its just that you probably won't get as much power out of the array as you expected. The clearest, easiest to understand write up on sizing I have found is at the AM Solar site: http://www.amsolar.com/ . This is the organization LD buys its solar equipment from.
Re: Solar Panels Reply #3 – April 20, 2006, 01:01:44 pm Yahoo Message Number: 65666"1) If you have multiple panels, do they all have to be the same size i.e., watts, if you decide to add additional panels?2) If you add panels, can they be from a different manufacturer? 3) Is there some rule of thumb regarding the ratio of batteries to watts of the solar panel?"Others have given detailed answers, but let me offer simple ones.1. Wattages need not match; manufacturers need not be the same, but you must match number of cells when adding new panels. This is easy--just look at the panel and count the cells (typically either 36 or 44).3. My rule of thumb about batteries is that if you have more than 250W-300W of panels, you'll probably need to add batteries to get full use out of your panels. No matter how many panels you have, when the sun goes down, it's your batteries that carry the load, and it doesn't matter whether they were fully charged at 10:00 a.m. or at 3:00 p.m....they'll still only last as long as they last. Unfortunately, adding batteries is much more complicated than adding panels. :-(Andy BairdRock Hound State Park, NM
Re: Solar Panels Reply #4 – April 20, 2006, 02:45:08 pm Yahoo Message Number: 65674QuoteI have a couple of questions re: solar panels. 1) Hooking all panels in parallel - necessitating only one lead in to the controller - size the controller to handle the maximum current (amps) of all the panels added together.2) Keep technology and cell count the same. E.g., if one panel uses polycrystalline cells, keep all the same number of cells and of that type.Steve
Re: Solar Panels Reply #5 – April 20, 2006, 03:18:57 pm Yahoo Message Number: 65678"3) Is there some rule of thumb regarding the ratio of batteries to watts of the solar panel?"The maximum sustained charge rate for lead-acid batteries is 1/8 (C/8) the capacity of the battery. Your LD should have a 225 amp hour battery. This works out to be 28 amps, about 340 watts of panels. That's would equal 4 - 85 watt panels. Any more panel output will just be wasted unless more batteries are installed. Replacing the factory batteries with two AGM batteries would enable you to use even more panels because their maximum charge rates are much higher. LD does not recommend more than two roof-mounted panels but plenty of us have more, some a lot more. Proper panel installation is a must to prevent damage to your LD.Before going further, you should determine your daily energy use. Ideally, the panels should provide a minimum of 120% of your daily energy consumption. The extra 20% cover losses in the charge/ discharge cycle. Additional output is even better, up to a point. Realize that panel output is significantly lower in the winter due to the sun being low in the sky. Tilting panels can help but are a lot of work and require positioning of the MH to maximize output. Most mount them flat and call it a day (self included). I like to size battery packs with a capacity to supply power for three days before drawing the battery down to less than 50% of capacity. The extra capacity helps cover cloudy or rainy days. The stock battery would provide only 38 amp-hours per day of power, using this method. If you are a serious boondocker, a battery upgrade is suggested. The alternative is to use the generator for charging. Unfortunately, the on-board charger does not provide sustained high rates of charge so many hours of run time are needed to fully charge the battery or to a minimum of 90% of capacity. Many add a larger 'intelligent' charger to reduce generator run time Regularly discharging a deep-cycle battery below 50% will drastically reduce the batteries' life span. This is OK as long as you do not mind the expense of doing this every couple of years. Adding more batteries can be very expensive due to the high installation cost of a professional job. For most, it's probably cheaper to replace the batteries more often. The cost of two new batteries should be around $200. A four battery installation will be many times more.Larry LD just upgraded to 245 watts of solar and 450 amp/hour battery pack. Details coming soon.
Re: Solar Panels and battery pack Reply #6 – April 20, 2006, 04:37:49 pm Yahoo Message Number: 65681QuoteLD just upgraded to 245 watts of solar and 450 amp/hour battery pack. Details coming soon. Larry, I know you said "details coming soon", but I wonder if you can provide any other info at this time. LD is building our 26.5 MB now and I'd love to have 450 amp-hours! The construction is about half done and we'll be visiting the factory tomorrow. Thanks, Dave
Re: Solar Panels Reply #7 – April 20, 2006, 05:40:19 pm Yahoo Message Number: 65686"Keep technology and cell count the same. E.g., if one panel uses polycrystalline cells, keep all the same number of cells and of that type." Steve, this is the first time I've heard anyone say that the solar panel's *technology* must be matched. Why would this be necessary? The only reason I can think of would be if polycrystalline cells output a different voltage than monocrystalline, and as far as I know that's not the case.Andy BairdRock Hound State Park, NM
Re: Solar Panels and battery pack Reply #8 – April 20, 2006, 08:24:22 pm Yahoo Message Number: 65707"I know you said "details coming soon", but I wonder if you can provide any other info at this time. LD is building our 26.5 MB now and I'd love to have 450 amp-hours! The construction is about half done and we'll be visiting the factory tomorrow."DaveThe changes I have made would not be done by LD for you or anyone. The only Factory upgrades available to you are the 2 solar panel option and the T-145 battery upgrade. It is probably too late to make either of these changes unless you had ordered them earlier.New Solar Panels http://tinyurl.com/fu7th New Battery pack http://tinyurl.com/jx95y Entire Site http://pg.photos.yahoo.com/ph/lw5315us/my_photosLarry
Re: Solar Panels Reply #9 – April 20, 2006, 09:07:12 pm Yahoo Message Number: 65713QuoteSteve, this is the first time I've heard anyone say that the solar panel's *technology* must be Quotematched. Why would this be necessary? The only reason I can think of would be ifQuotepolycrystalline cells output a different voltage than monocrystalline, and as far as I knowQuotethat's not the case. Temperature coefficients are usually different as the manufacturing process varies, and the electrical characteristics are different too. You won't likely see a lot of difference between poly and mono, but it's better to avoid possible problems. Certainly, the amorphous and plastic cells would not be worth mixing with silicon technology. Unfortunately, luminance/power curves are not usually published with sufficient detail to allow precise matching by users, but if the technology is consistant, you're pretty much assured of optimal performance.Another option would be separate charge controllers for each set of dissimilar panels, but this is - at the least - inelegant.Steve
Solar Panels Reply #10 – April 23, 2006, 07:31:54 pm Yahoo Message Number: 65875First thanks to Bill H., Lindley, Andy, Steve, Larry and Bumper for responding to my questions in message 65647.If I understand you all correctly, simply stated, I would be better off getting more batteries than adding more panels. For instance, I currently have 4 - 55 watt panels for a total of 220 watts with 2 - 6 volt batteries. I do NOT have a generator. I am hoping to get the Prosine 2000 and 4 - AGM batteries and a solar boast. Does this seem like a reasonable config, at least to start with? I want to be able to boondock without having to worry (too much) about having enough power.Kathi
Re: Solar Panels Reply #11 – April 23, 2006, 08:48:12 pm Yahoo Message Number: 65880Quote First thanks to Bill H., Lindley, Andy, Steve, Larry and Bumper for responding to my questions in message 65647.If I understand you all correctly, simply stated, I would be better off getting more batteries than adding more panels. For instance, I currently have 4 - 55 watt panels for a total of 220 watts with 2 - 6 volt batteries. I do NOT have a generator. I am hoping to get the Prosine 2000 and 4 - AGM batteries and a solar boast. Does this seem like a reasonable config, at least to start with? I want to be able to boondock without having to worry (too much) about having enough power.Quote Kathi Before I agree with you, we need to think about your user profile. Do you full time? If you do, where do you spend your winters? That is, is there sun almost every day or are there long(er) cloudy spells? Are you happy with your current supply of 12V electricity when the sun does shine every day so you just need to have more storage to carry you over cloudy days, or do you just want to have more electricity available? Based on Greg Holder's (e.g., AM Solar) guidelines and my experience, which is limited but lines up with Greg's, I would say you are on the cusp. He recommends 200 amp hours of battery storage and 150 Watts to 250 Watts of panels for a conservative user. That describes your present system so the question is, "are you a conservative user?"From his data, your panels will generate about 50-60 amp hours of charge daily which is sufficient if you are a fairly prudent user of electricity. If that is the case, probably adding more storage capacity would be in order since that will allow you a few more cloudy days before you run out of 12V power. On the other hand, if you really need MORE 12V electricity, you must add solar panels first and storage later. You should have a bigger source if you are using more electricity. That is, if you are now using all the electricity the panels create, on a day by day basis, there is no need to add a bigger place to store it. Wanting to add a prosine 2000 makes it sound like you need more power, not just a place to store it.When doing a lot of dry camping, having a battery monitor that actually measures the amp-hours of battery charge and discharge makes managing 12V electricity usage very easy. There are several models. The Xantrex Battery Monitor, for instance, has a lot of detailed readout, but features a fuel gauge readout so one can see the charge in the house battery at a glance. You might consider adding this to your wish list as well.Linley
Re: [Life With A Lazy Daze RV] Solar Panels Reply #12 – April 23, 2006, 09:28:49 pm Yahoo Message Number: 65886I have been seeing a lot of Prosine 2000's on ebay in the $810 to 1000 range. They are one that had a recall on it and have been fixed but I am seeing no negitive feedback on the units. I found a Prosine 3000 for under $1000.
Re: [Life With A Lazy Daze RV] Solar Panels Reply #13 – April 23, 2006, 10:22:38 pm Yahoo Message Number: 65894Thanks Matt. I've been checking ebay and have seen these recalled Prosine listed. I have wondered if there might be a negative to getting one of them.Kathi
Re: Solar Panels Reply #14 – April 23, 2006, 10:46:41 pm Yahoo Message Number: 65898Linley (sorry about misspelling your name before) Yes, I live fulltime in my LD. I plan on spending the winters in the southwest US. As to my current situation, I have been using hookup almost exclusively, one, because I apparently am not a conservative user though I try to be, and two, because my current batteries need replacing. My biggest problem up to now has been trying to determine where I am at with my battery usage. Your suggestion of having the Xantex Battery Monitor is something I definitely need and will add to my wishlist. The main problem with adding additional panels is the space limitations on my roof as well as the fact that I am worried about adding additional weight (and having the problem like Andy with the door/ceiling).QuoteBefore I agree with you, we need to think about your user profile. Do you full time? If you do, where do you spend your winters? That is, is there sun almost every day or are there long(er) cloudy spells? QuoteAre you happy with your current supply of 12V electricity when the sun does shine every day so you just need to have more storage to carry you over cloudy days, or do you just want to have more electricity available?Quote Based on Greg Holder's (e.g., AM Solar) guidelines and my experience, which is limited but lines up with Greg's, I would say you are on the cusp. He recommends 200 amp hours of battery storage and 150 Watts to 250 Watts of panels for a conservative user. That describes your present system so the question is, "are you a conservative user?"Quote From his data, your panels will generate about 50-60 amp hours of charge daily which is sufficient if you are a fairly prudent user of electricity. If that is the case, probably adding more storage capacity would be in order since that will allow you a few more cloudy days before you run out of 12V power.Quote On the other hand, if you really need MORE 12V electricity, you must add solar panels first and storage later. You should have a bigger source if you are using more electricity. That is, if you are now using all the electricity the panels create, on a day by day basis, there is no need to add a bigger place to store it. Wanting to add a prosine 2000 makes it sound like you need more power, not just a place to store it.Quote When doing a lot of dry camping, having a battery monitor that actually measures the amp-hours of battery charge and discharge makes managing 12V electricity usage very easy. There are several models. The Xantrex Battery Monitor, for instance, has a lot of detailed readout, but features a fuel gauge readout so one can see the charge in the house battery at a glance. You might consider adding this to your wish list as well.
Battery monitors (long) Reply #15 – April 24, 2006, 01:28:12 am Yahoo Message Number: 65906Let me second Linley's recommendation of the XBM (Xantrex Battery Monitor) or the similar Link-10. I spent a difficult fall and early winter--I seemed to be constantly running out of power. Installing more solar panels helped, but what I wanted most was hard information about how much power each light and electrical appliance was using, and how much reserve my batteries had left in them. All I had was a standard battery-voltage display, and that just doesn't tell the whole story. In trying to manage my power consumption, I was fumbling in the dark, which was very frustrating. That's why I purchased an XBM, which I installed day before yesterday. Already I can see that the information it provides will greatly benfiit me--not just voltage, but also...• net charge/discharge, so I can tell how much each appliance uses• consumed amp-hours, so I know how much I've drained the batteries • state of charge--an easy to understand percentage reading that's like a gas gauge for the batteries • time to go-- an estimate of how long the batteries will last at the present rate of power consumption ...plus lots of "historical" data like how many times the batteries have been cycled, what the lowest discharge point was, and so on. I believe an RVer who lacks this information is seriously handicapped when it comes to boondocking. I know I was! This, by the way, is the only time I've ever had occasion to disagree with Mike Sylvester's usually excellent advice. Mike argued that the HPV-22 solar controller installed by Lazy Daze would give me all the information I really needed, and that the XBM wasn't cost- effective (at about $300 plus at least that much in installation costs, unless you do it yourself as I did). But to me at least, the XBM is worth every penny. The HPV-22 only tells me the battery voltage at the present moment and the rate of charge from the solar system. It doesn't tell me how much power is going out to lights and appliances (including those running on my 2,000W inverter), nor how much is coming in from the converter when I'm plugged in. And of course it doesn't tell me how much power I have left, except by not-very-accurate guesswork on my part. The XBM does all this and more. As long as I'm on the subject, let me try to clear up something that confused me and my friends when buying our battery monitors: the differences between the widely-known Link-10 and the newer XBM, both of which are Xantrex products. Let me say up front that you can't go wrong with either one, as they are about 90% similar in their capabilities. The XBM is the current model; the Link-10 is being phased out, but is still available at attractive discounts if you shop around. (Try West Marine). I don't claim to be 100% complete, but here are the main differences I've noticed after comparing my XBM with Kate's Link-10 and reading both manuals. (By the way, the manuals are available as PDFs from Xantrex's website...if you really want to know all about the gadget before you buy, that's the best way.)Link-10 • Exemplary manual covers both installation and operation in clear prose with good illustrations • Red LED display with two pushbuttons, somewhat confusingly labeled "Sel" and "Set" • Shows voltage, net charge/discharge, amp-hours used and time to go (but not charge state percentage)...plus historical data on demand • Display can be set to display all four readings in sequence • Round case with "ratchet ring" simplifies mounting: drill one 2" hole, shove the Link-10 meter in and snug up the ring.XBM • Terse, rather technical manual; separate installation sheet that's poorly written and in tiny type with amateurish layout, so it's really hard to read. (It also has a few inconsistencies, like telling you to look for labels that aren't there.) • LCD display with yellow-white backlight looks classier to me than red LEDs • Shows voltage, net charge/discharge, amp-hours used, charge state percentage, and time to go...plus historical data on demand--in other words, you get one more very useful) reading compared to the Link-10. • Display can *not* be set to display all five readings in sequence. (Why they dropped this feature, I can't imagine) • Square case mounts with small screws at corners; requires 2" round hole. Both devices come with a 500A shunt that mounts in your battery compartment; both require a passel of other hardware that isn't included, plus at least five conductors of twisted-pair cable. My advice: if you plan to do your own installation, call Dave at AM Solar and tell him which unit you have and how much cable you need. He will bag up everything down to the last crimp-on lug and piece of shrink tubing needed, and send it to you. I hope this has been helpful! I thnk these battery monitors are great for anybody boondocking and trying to learn to conserve power.Andy BairdRock Hound State Park, NM
Re: Battery monitors (long) - to Andy Reply #16 – April 24, 2006, 01:52:14 pm Yahoo Message Number: 65927"...I hope this has been helpful! I thnk these battery monitors are great for anybody boondocking and trying to learn to conserve power."Quote Andy Baird Rock Hound State Park, NM Great summary and info, Andy. Has your new solar panel and battery system met your power needs over the winter months or have you had to use shore power from time to time?Chris
Re: Battery monitors Reply #17 – April 24, 2006, 06:09:29 pm Yahoo Message Number: 65938"Has your new solar panel and battery system met your power needs over the winter months or have you had to use shore power from time to time?" In a word, no. My power consumption is so excessive (thanks to running a desktop computer all day and all night ;-) that in the dead of winter, I rarely had enough solar power. I ended up spending a month in a commercial campground with hookups in Twentynine Palms. By early March, as the days got longer, everything was much better. :-) Now with that said, I'm sitting here in Rock Hound State Park, NM, with water and electric hookups--because with my New Mexico annual camping pass, it only costs me $4 a night...so why not? :-)Andy BairdRock Hound State Park, NM
Re: Battery monitors Reply #18 – April 24, 2006, 10:12:26 pm Yahoo Message Number: 65942QuoteNow with that said, I'm sitting here in Rock Hound State Park, NM, with water and electric Quotehookups--because with my New Mexico annual camping pass, it only costs me $4 aQuotenight...so why not? :-) We agree! The NM State Park Pass is an awesome value for us living in New Mexico! And others...if they stay long enough. Now that we will have an LD and can take off a little easier on weekends. I think we will be really getting a good amount of camping on it. Plus, we are homeschooling our soon to be nine-year-old next year. We have not made it down to Rock Hound or City of Rocks nor Oliver Lee yet and have lived here for 32 years! I have never seen Carlsbad Caverns yet! Shame on me!Blessings, CK
Re: New Mexico Annual Camping Pass Reply #19 – April 24, 2006, 11:58:05 pm Yahoo Message Number: 65948"The NM State Park Pass is an awesome value for us living in New Mexico! And others...if they stay long enough." And that doesn't have to be very long! For NM residents, the annual camping pass pays for itself in just 18 days. For nonresidents like me, it pays for itself in 23 days. (Seniors get an even better deal.) After that, you can do all the dry camping you like for free, or camp with water and electric hookups for $4 a night...in some of the country's most beautiful parks. And you can camp for three weeks at a stretch in any one park, go somewhere else for a week, and then come back and spend another three weeks if you like.No other state has a deal this sweet--boy, do I wish they did!Andy BairdRock Hound State Park, NM
Re: [Life With A Lazy Daze RV] Re: New Mexico Annual Camping Pass Reply #20 – April 25, 2006, 03:32:03 pm Yahoo Message Number: 65964QuoteAnd that doesn't have to be very long! For NM residents, the annual camping pass pays for itself in just 18 days. For nonresidents like me, it pays for itself in 23 days. (Seniors get an even better deal.)After that, you can do all the dry camping you like for free, or camp with water and electric hookups for $4 a night...in some of the country's most beautiful parks. And you can camp for three weeks at a stretch in any one park, go somewhere else for a week, and then come back and spend another three weeks if you like. OK, I'll bite--just how much is a pass for us non-residents? I'm getting ready for my spring/summer exploration tour to find where I want to re-locate. NM is sounding more and more like someplace I should thoroughly check out......any info about NM much appreciated![Non-text portions of this message have been removed]
Re: [Life With A Lazy Daze RV] Re: New Mexico Annual Camping Pass Reply #21 – April 25, 2006, 03:45:11 pm Yahoo Message Number: 65966Non Resident Annual Pass (good Jan 1-Dec 31) $225. Once paid, drycamping is free, Electric & Water $4.00 a night, 21 day limit per park, but you can move and come back in). A note re Seniors- The SR discount is only effective for NM residents.But, there are LOTS of parksKateIn Serenity/Cholula, the Red 30TB . . . Want to find us? Click below, we're #3096 http://map.datastormusers.com/user1.cfm?user=3096
[Life With A Lazy Daze RV] Re: New Mexico Annual Camping Pass Reply #22 – April 25, 2006, 03:48:45 pm Yahoo Message Number: 65967Here is the website for NM State Parks. Go here for info on all state parks, reservations, and also to purchase the pass http://www.newmexico.reserveworld.com/ http://www.newmexico.reserveworld.com/>New Mexico is a great state!CK
[Life With A Lazy Daze RV] Re: New Mexico Annual Camping Pass Reply #23 – April 25, 2006, 03:58:36 pm Yahoo Message Number: 65969Oops, that was for ressies. Here is the actual NM State Park page: http://www.emnrd.state.nm.us/emnrd/parks/
Re: [Life With A Lazy Daze RV] Re: New Mexico Annual Camping Pass Reply #24 – April 25, 2006, 04:18:57 pm Yahoo Message Number: 65970Thanks Kate!
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