Intrepid Solar Solutions
When it comes to angst in planning mods to the Four Wheel Granby, AKA Intrepid, fitting it out for solar comes right behind dealing with its lack of interior space. On the face of it, adding solar to the Granby is unusually easy: it comes prewired for solar whether you want it or not. There’s an SAE socket installed on the roof, and another on the back wall for plugging in ground-based solar panels. Order Four Wheel’s battery option, and you get your choice of one or two 80Ah (amp-hour) AGM batteries, as well as a battery separator to keep you from running down your truck’s starting battery. You can order their solar panels, whether roof-mounted, ground, or both, with a charge controller that comes along. It’s easy, it works well, and you’re rolling the instant you take delivery.
Heck, with 240 watts of panels available from the factory powering an optional 160-some Ah of batteries, it’s all anyone could want. I mean, it’s enough to run the compressor fridge and a laptop, as long as weather conditions are decent and you don’t overdo it. And, it’s a “top-heavy” system: there’s enough overage in the watts-to-amps ratio to make for a decent go in marginal weather, especially considering that the fridge will do its best to screw up the morning battery recharge. A 1/1 ratio (100 watts of panel for each 100 Ah of battery capacity) is considered the minimum in sunny climes. A 1.5/1 ratio is optimum for handling haze or light overcast, and I’ve found that 2/1 with plenty of battery capacity is highly preferable in the murky upper-Midwest. In the Great Southwest, as long as you trim back usage to essentials, a 2/1 ratio can weather you through nearly anything, no matter how long it lasts. (This assumes that you’re using quality equipment in your system.)
But in my world, the factory options are both expensive and inadequate, a combination of sins which cannot be forgiven. I gravitate more toward the Wretched Excess category, and one of my favorite tongue-in-cheek mottos is “Too much is almost enough”. But unlike the Defiant, bestowing wretched excess upon the Granby is not a straightforward process. There are four primary issues involved: limited interior space for batteries (surprise!), a frame structure not friendly to inordinate amounts of added floor weight, a solar wiring harness designed for linking roof and ground panels in parallel (to combine wattage), and a roof which requires manually hefting up whatever solar panel weight you add to it. Sound overly technical? It isn’t, if you take on the issues one by one.
The Granby Front Dinette can accept two factory Group 24 AGM batteries in a cabinet at driver’s side rear. This is an unvented compartment, since it doesn’t need to be vented, because AGM batteries are very unlikely to vent acid gas, ever. That ends the high risk of corrosion of any electronics and connectors in the area, as well as the risk of a nearby spark igniting the highly flammable battery gas. It’s also good for you, in that you won’t have long-term exposure to acid gas in a very confined space. You want to use cheaper flooded batteries in there, that’s your business. Your camping buds may advise you otherwise, but using vented, flooded batteries inside the same enclosed space where you live is akin to trying to use your lawnmower as a hedge trimmer. It will work, but might cost you more than you bargained for over time.
My 104Ah Life-Line AGMs are larger, and don’t conform to any particular group size. There’s just enough space to fit one in the compartment, along with my 45A solar charge controller. If I set them on end, there’s room for two, but the controller would have to go elsewhere. And, whatever batteries go in there need to be strapped down – a spongy little Toyota bouncing around on the rocks is bad enough, but an F-250 or above is the nightmare scenario as far as cargo scrambling goes.
So although the factory 160 Ah battery pair is adequate for reasonable people, even 208 Ah is not enough to float my boat. Why? Three reasons. I’m sitting on a handful of these 104 batteries, already bought and paid for. I regularly spend time in that murky Midwest, where the best you can hope for after three days of rainy overcast is a few days of haze to recover. And there’s that compressor fridge which, despite being wonderfully efficient, still tries to throw a wrench in getting a full recharge. Chronic failure to fully recharge kills batteries faster than you can shake your cane at a smart-alecky whippersnapper, and the deeper you dive into a battery’s reserve capacity, the fewer cycles it will provide before it poops out. Since I’m not into eating wilted or spoiled produce, staying off my computer, or replacing expensive batteries, I prefer to over-specify and reap the benefits. But, that also means that, in the Granby, I’ll also have to be willing to live with the space encroachment and weight that adding battery capacity causes.
Considering the very limited space available, that’s no small thing. In my setup, one battery will be strapped into the compartment, along with the rather large Morningstar 45-Amp MPPT battery charge controller. All that’s needed is to hook up my battery to the factory leads for power and solar, and wire it to the controller a few inches away. Adding more battery capacity is a little more difficult. A few feet farther forward is the driver’s side dinette bench understorage, and running enough submerged battery cable from the battery to that bench will be a fairly easy matter, allowing additional batteries to be strapped in there.
Of course for me, Mr. Persnickety, that’s not good enough. In order to better even out the weight distribution left-to-right, I’d want that cable to end inside the passenger’s side bench storage compartment instead. Once there, it’s simply a matter of how many batteries I’m willing to sacrifice storage space for. More batteries means less charge tampering by the fridge, and a much longer service life for the battery pack. It also means the ability to recharge the e-bike battery at will, or conduct my own 24-hour Three Stooges Marathon. That’s the clincher, isn’t it? If I can pack 3 more batteries in there, I will. But I won’t know just how bad the situation will be until I get in there and survey the wreckage. That’ll be awhile yet.
Butchering the Granby just enough to pass a 4AWG wire from one compartment to the other should be do-able, if regrettable. Weight is the issue. That’s not for the Ford’s sake, since the additional weight is low and forward, and the Ford won’t drop any fuel mileage or handle like it knows they’re there. The issue will be that it may be best to drop a length of plywood under the additional batteries to distribute weight between the camper’s structural crossmembers underneath. And, if the camper is ever removed, those extra batteries should be disconnected and removed first. The Four Wheel is not designed to be hung on its jacks and lived in without the floor being fully supported by something underneath it. Removing the Granby from the truck’s bed with 60-180 pounds of batteries on its floor would not be the best thing to do. Even placing that much weight in one spot on the floor is of some concern, since while the truck is in motion, the effect on how the frame twists with the truck’s bed is unknown.
I take this kind of thing seriously because a few years ago, a couple of popular bloggers on the road had the floor section of their fairly new major-brand hardside truck camper come off and hit the ground while it was up on jacks. Maybe it was full waste tanks, but there was no explanation given. And there had apparently been no caution about supporting the floor. There is on the lightweight Four Wheel, thanks to a dealer’s salesman, so I don’t discount it. At any rate, the manufacturer said it was too bad and walked away under the disclaimer of the warranty not applying to full-time use. The couple was not thrilled, but fortunately had the resources to change to another type of RV. I’d like to avoid that, because such an event would end the show, not reschedule it.
Thing is, the more battery capacity you have, the more solar panel power you need to feed it, particularly if you’re not going to be angling them toward the sun, and more particularly if you will occasionally be parked in shade, or in the glorious Midwest. I tried to think of any way I could to reuse my existing residential 195-watt solar panels. After asking the factory about the roof locations of dual vents and the solar outlet, it looked like there might be space to jam two big panels up there, but the issue of weight quickly overrode the detail of how to mount them without puncturing the roof with new holes. Two panels weigh 86 pounds, a weight that the factory was uncomfortable with on the long Granby roof. It’s thin, and its tubes are thinwall. The panels would need to be toward the front and back edges where the supports are, and the available roof racks are more expensive than the panels, negating the “savings” of reuse. Their own weight adds to the problem. Hefting that roof weight up or using jacks to get it started did not appeal. Warping the roof while lurching over rocks did not appeal, either.
Okay then, so ground panels. Certainly not the best situation, because while they can be a challenge to carry around and store away someplace, they have enough sail area to come up and over in a stiff wind when angled off the ground. Being mostly glass, that’s a problem, and there’s certainly no shortage of wind in the West. Stakes and tie-downs are okay, but require packing a big hammer as well as a reliable way to get them back out of the ground. About a third of the camps I’ve been at resist staking. But where to store even one panel? Interior of the camper? That means that the panel is outside on the ground whenever I’m inside the camper. The range of places I go, that’s unacceptable. A blog called Two Happy Campers stowed their extra panel in a fabricated rack slung underneath the overhanging bed section of their Four Wheel, padlocked. Since they were using an earlier model of F-250, I contacted them and asked about it. It looked workable. As a final double check, I found a dimensioned drawing online of their year of truck, and compared them to my 2008’s drawing, and Four Wheel’s drawing. Uh-oh. My bed height is two inches lower relative to the cab roof, meaning that their ample room to slide a panel in would not exist for me. Bad news for reusing any of my high-performance panels. This was going to hurt.
The solution then swung toward using lightweight, semi-flexible solar panels. On the face of it, this is a happy solution. At about four pounds each, six of these 100-watt panels can be Velcro’ed or otherwise adhered directly to the roof surface. That’s 600 watts, which is what the Defiant uses to recharge its 400Ah “office” battery pack that works so well. The additional load on the roof is minimal, and the weight is distributed well. But it’s not as productive a setup, because the lightweight panels can’t be angled toward the sun for greater efficiency. They also take another efficiency hit by the lack of cooling air between them and a white (but still hot) aluminum roof. Not to mention that flexible panels are considerably more expensive than traditional framed glass panels. Fabricate and adhere an aluminum rack on the roof, to hold them away, and perhaps even to angle them? Not here. The 3-season use of the Intrepid will be at higher sun angles, and the panels must be so close together to fit that they would tend to shade each other when angled up. Then there’s that wind thing, and the basic PITA setup factor to consider. Nope, I’ll take my losses and live with them. See what happens.
One timely detail. The factory solar wiring is 10AWG, a common and reasonable thickness of solar wire. It will handle the factory panels just fine. But, if you try to pump 600 watts through that wire, you’ll be converting a heap of those watts into wasted heat before they ever get to the charge controller. The solution is to connect all of the panels together in series, much like the stacked cells in a long flashlight, positive to negative. Instead of that wire feeding 600 watts at say, 18 volts, the new result is 100 watts at some 108 volts. Since wires are not stressed by voltage like they are watts or amps, no wire upsizing is needed. Only MPPT controllers can handle higher voltages like this, but since I already have one, there’s no goofing with wiring or buying a new controller. It can’t handle more than 600 watts, but I can’t physically pack any more panels up there anyway.
I also haven’t mentioned that the word on the street indicates that flexible solar panels are much more vulnerable to crippled output caused by shading even small amounts of a panel. That’s not good, though using an MPPT controller can help with that. For you tech-heads, an even more effective solution that will come along eventually is here. As one reader pointed out, a ground panel or two may occasionally be handy to get out from under tree shade. This can be done, but there are a few things going with such a fix here. The first is that my controller is maxed out at 600 watts of panels and 150 volts. With the roof panels in shade, I might be able to get away with putting one or possibly two additional panels on the ground without blowing the controller (generating a total Voc of 129.6 volts/151.2 volts), but I’m uncomfortable with the thought of laying out more panels (with their cost) and having the sun work through a hole to kill a $400 controller.
However, given the probable inefficiencies, I’d think I could safely get away with one ground panel, connecting through the outlet at the rear of the camper. I could alternatively peel a panel off the roof and lay it out in the sun. First though, I’d need to rewire the camper’s solar harness so that the roof and ground panels stayed in series together. As it is, the ground panel would come in in parallel, which would not be good. I’m not big on rigging a switch to alternate between the two panel sets, either – since I’d forget to use it. Although the Defiant’s system has the same “numbers” and suffers very little in poor conditions, the poorer shading performance of flexible panels, their flat layout and their heating issues may well prompt me to use a ground panel in the future. But that’s not something that I’d like to hobble myself with from the start. That type of problem needs to prove itself necessary first, so I can tailor the solution to suit. 12-volt ground panels with long wires aren’t as efficient as I’d like to think, even wired together in series. And the wiring junction boxes (the wiring connections) on semi-flexible panels aren’t as hardy as they need to be for being handled a lot. It’s something to let soak.
So in this post, we’ve looked at what produces the power, what stores the power, and in the case of the compressor fridge and the e-bike charger, what uses the power. The fridge doesn’t use much juice, but since it runs on and off all day, its power needs add up. The e-bike charger is used occasionally, running for up to five hours while pulling 120 watts through an inverter. That’s a pretty stout amount, equalling the office desktop computer’s pull in the Defiant. When they’re both on at the same time, it needs to be a bright day for the office pack not to be impacted. And don’t forget the 28” flat screen TV in the Defiant’s holodeck. I like to watch a movie or two most evenings, and that takes some power – about half of what the computer does.
I’d like to be able to do the same things in the Intrepid, but with adjustments. The Defiant’s office pack discharges by only 20-25% per day on average. That’s pretty good, but the pack would live much longer if I could decrease that to 10-15% average. Working against that is the addition of the compressor fridge and the less efficient new solar panel layout. At this rate, we’re working deeper into the hole, not out of it. Since the big-screen movie TV and the desktop computer will be impossible to stuff into the Intrepid, what’s needed is a system that can combine both tasks into a single system that draws much less power over the course of a 24-hour day.
In my case, that’s a Macbook, acting as an all-in-one solution to conserve power. But it can’t be just any model of Macbook, since it ideally needs enough ports and enough functionality to take over office duties should the big iMac decide to end it all. That means loading DVDs, running a film scanner and flatbed scanner, hooking up to a sound system and several external hard drives, and running the same or equivalent software programs so that I can keep doing what I do. In the case of new MacBooks, the good news is that Apple has trimmed power supplies down to a mere 45-watt maximum, and the laptops are commendably thin and light. The bad news is that they accomplished this by trimming off DVD drives and most of the legacy ports that would be able to connect to my “obsolete” office equipment. There are adapter cables offered, but they can be gimpy and are something to lose.
So, I was delighted to find one older model tucked down at the bottom of the sales pages. It kind of looked like it would soon be on the chopping block as the newer, sleeker models took over. Not to diss them, since they are indeed thinner, lighter, faster, have longer battery runtime, and screen resolution just beyond the ability of the human eye to perceive anything finer. But that latter point is what convinced me to stick with old and clunky. Stunning screen resolution doesn’t do me any good – I can’t read restaurant menus without glasses, and even then, many things are touch and go. Called the 13” Macbook Pro, it uses a 60-watt power supply and includes an onboard DVD drive and ports for ethernet, Firewire 800, USB3, Thunderbolt 1, and a slot for the type of memory card that my camera uses. Handy.
The clincher was that this relic had an option to replace its hard drive with a solid-state drive. Oh happy day! The newer models come with a faster version called flash drive, but the speed difference didn’t matter to me. It’s the longer service life. What’s the first thing to go away on a laptop, apart from its battery? The hard drive. It’s an assembly of spinning platters and electromagnetic arms resembling a record turntable. Used daily and hard, they don’t last very long any more, and Heaven help you if you don’t have a backup of your data. If you keep your laptop into the “wow, how old is that?” stage as I do, you eventually find that even locating a drive in the capacity that the unit will tolerate and with the connector type you need, can become a real problem. And the one or two sources that still have it are convinced that they are offering a historic national treasure for sale. Solid state drives, like flash drives, are a rough equivalent to USB memory sticks, only with much faster connections. They do wear out but, compared to even a server-grade hard drive, that takes quite a long while. Their downside is cost. It’s brutal. I could only afford 1/4 of what my desktop has. Still, it’s enough to get by on.
What pushed me toward the extra expense was my Model 1 iPad that I’ve had since early 2010. It’s not real good for Internet stuff anymore, because the Internet has moved on to protocols that the iPad’s operating system can’t deal with, and the operating system can’t be upgraded past a certain cutoff point. YouTube videos are no longer viewable either, since YouTube recently changed their format. I mainly pull it out for sitting at the laundromat with WiFi to watch episodes of Comedians in Cars Getting Coffee, for listening to podcasts and music, and for MVUM maps when trying to see if I’m on a camping-approved road in a national forest. Thing is, the little bugger still works like Day One, while the big iMac has chewed through two hard drives already (Seagate 1TB, all covered in warranty while out of warranty) and is on its third, and more if you count the external drives that I attach to it. The iPad uses flash-style memory, and when the need for a low-draw laptop surfaced, that got me to thinking that I should step away from a conventional internal hard drive.
In practice, the Macbook Pro laptop works well. It boots up in 20 seconds, and needs no running maintenance other than what’s called a file permissions check every now and then. There’s no such thing as defragging with it, since solid state drives don’t hack up files into different sectors. There are no fans and no cooling slots to accidentally block off, so no laptop platform is needed when it’s on your legs or on the bed. It doesn’t even get warm, which is almost a disappointment on cold mornings, but a boon in hot weather. The keyboard lights up when your workspace eases into darkness, which I find that I prefer to lighting up the whole area. If it’s plugged into power while the battery is already charged, the power draw is even better than I’d hoped. It does all the blog photos just fine, and although I have not yet tried the ancient film scanner’s software on it yet to see if it’s compatible, it does a plenty good enough job of playing movies from both of the external 3TB hard drives they are packed onto. The volume is loud and crisp enough, if I’m not parked next to a busy highway or beside an idling semi. If I care to pack the original DVDs along (which I won’t), it can play those as well, which helps in those times when I trip over a goodie at a resale shop.
At this point, it looks like it will acceptably take over for both the studio desktop and the centre d’entrainement while I’m on the road in the Intrepid, compensating very nicely for the solar havoc that both of those hogs create in the Defiant. If I can find space in the Intrepid for the Defiant’s full office pack, I will be very curious to discover how the new mixture of solar panels and running devices sorts itself out on daily discharge averages. Although the Macbook can obviously run on its own battery for up to 7 hours, it can run off an aftermarket 12VDC power supply or its own 110VAC adapter. However, any external hard drive deck feeding it photos or movies requires a small inverter, period. I have a few pre-existing options in that department, but will sort those out in situ.
It’s no secret that laptops have long been standard issue in campers of all stripes, so this is certainly no innovation. What’s a little different is the range of peripheral equipment that it’s expected to interface with, and that I can simply carry on in a very similar fashion to all that I do and enjoy in the Defiant. I’d expected to be hobbled with exceptions, workarounds and limitations, just as I have been up to now whenever the desktop was not available on the road, but there are few. Thus, my joy.
In finishing this post at long last, I realize that some readers may have some antipathy toward Apple products and the snobby beatniks and subversives that use them. That’s okay. I myself began with Windows 3.1 at its beginning, and dutifully stuck with IBM-style hardware of many kinds right up through and past the demise of Windows XP. I also dabbled heavily with various forms of Linux on the same hardware. That lasted right up to the point where I acquired a well-used and hopelessly obsolete Apple G3 desktop on a lark, when I transitioned from troubleshooting problems, sifting through thick reference manuals and Googling error messages to simply getting my work done. That was kind of a “holy crap!” moment, changing my concentration from a device to my task. Now, Apple’s products aren’t nearly as seamless or issue-free as they used to be in the old days, but they still work for me, and I ain’t going back anytime soon. As for you, I’m sure that equivalent hardware exists for Windows, and your implementation would be very similar in an attempt to combine functions, save on power usage and extend the working service life of the laptop itself. Have at it, and enjoy!