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Discussion in 'Hangar Talk' started by Ted, Jul 17, 2020.
Just get working on a solar/battery system. I can feel you getting low on projects...
I do keep on thinking about upgrading the solar/battery setup. My batteries are showing their weakness and so I may be forced to do something there. The real problem is that there's no way to run the AC without the generator - I just don't see making enough solar/batteries to actually use it. Solar/battery will improve the other 8 months of the year (which account for... maybe 50% if that of our camping). Right now I have 4x GC2 flooded lead acid batteries, around 460Ah @ 12V total. It would be nice to double that (or more) and ideally something that will take power faster so they'll charge faster.
I have several ideas for what that could look like. Also not sure about spending the money on... any of it.
It’s not like hot section inspection on the MU-2 though. Comparative economics and all that.
True. Our total investment in the RV is less than the cost of the hot section we did on the MU-2. But, this is our money. The MU-2 belonged to Cloud Nine and was a corporate asset.
I suppose when you figure that this is something we actually do intend on keeping for quite a while, it might make more sense to just spend the money on a good system that gets what we want. Although I do somewhat expect that at some point we'll end up replacing it with a Prevost (like right after I've done all the major work to this one), our real goal is to keep it until the kids are in college - if not longer. July will be 2 years since purchase, and I think we're on track for something in the range of 25-30k miles on it in that time period. There's really no reason why the major driveline components shouldn't be able to last us another 10 years like that. All the major driveline components on these things are designed to go far longer than they ever do on an RV.
So I guess spending money on a system sooner would be a worthwhile investment to consider. Now if only I could find a sponsor for the solar or the batteries. Or both.
It was a long time ago, but we used to find some smaller campgrounds where they only had something like 120v-20a circuits, probably to save overall cost in infrastructure. So enough to charge a battery and run lights and a fridge, but not enough for an AC. So we'd sometimes have to run a generator for the AC even with the power.
It's the body that gets you. When that happens, being able to salvage sub systems for transfer to the replacement can be a make or break. And agreed to value on the insurance policy, of course.
That makes sense. So far, the only time we've stayed someplace with that power capacity was at 6Y9. No AC was needed that weekend, though.
Every other place we've stayed if we've had a hookup, it's been at least a 220-30A.
Agreed, the body is the real thing that will determine longevity. But after we redid the floor (and did it right) following the leak, fixed the leak in the first place, and keep it indoors, that all puts us in a good position there.
As far as being able to salvage and transfer subsystems, honestly I think there's likely more effort than that's worth in for most of it. Batteries would be the easiest to swap over, though, making that a more logical expense. But the majority of the work we've done on this bus is really specific to it, and non-transferrable. Examples include the flooring, bathroom remodel, etc...
The taillights are installed on the RV. I'm really happy with how they came out:
I spent a bit of time thinking about the best way to do this, and then also doing the wiring so that it was all fresh and would hopefully not need to be touched again. This was a bit complicated in how I had to do it, mostly because the stock setup was screwed up and I wanted to use this in the best, most OEM-type way possible.
The end result is that each side has a pair of the GM squarebody taillights, one upsidedown on top of the other. The upper "reverse light" location I fitted with an 1156A for the turn signal on both sides. The two red lenses in the center are both 1157s for tail and brake lights, and the bottom reverse light is a standard clear 1156 for reverse. It all works well, and I'm happy with the look. It's a whole ton better than what they'd put in there originally.
That looks sharp.... Did you have to do much body work to get those to fit? It looks like was built that way.
Zero body work. This is what it had factory:
That’s two GM square body lights, one on top of the other. Square body lights are symmetrical, so you can just flip them upside down with no problems. I wouldn’t have done it this way if it required body work, I’m too lazy.
Put together a little video about my taillight upgrade for those interested:
We got back a few hours ago from a "short" (~2200 mile) RV trip over the past 10 days or so. The bus performed really well on the whole. We added 4 states to our visited states in the bus map, two national parks, and generally had a great time. On the way home, the bus passed 110k miles on the odometer. In the just under 2 years we've had it, that's a bit over 25k miles on it, giving it the highest miles of use out of any vehicle in the fleet over that time period (assuming that you don't count the Land Rover's miles getting towed behind the RV).
On the trip, I decided the excessive generator need was annoying me too much, and the batteries proved that they just won't last much longer. Doing my standard "go big or go home" method, I ordered 1200W worth of solar for the rooftop and will be installing that with a 100A charge controller. I'm going to run a trip or two with that and see what I think of it before buying a battery setup, but the intent will be to at least double the battery capacity. Interestingly, the RVs like mine that came with residential refrigerators instead of propane (and we've converted ours to residential) had double the batteries, so it sounds like I'm overall on the right track with that idea, and tripling the capacity is probably better if I can make that work.
There are some little items that need to be addressed (as there always are when we get home from a trip), and with the summer travel season upon us, that means I'll have to get cracking and closing out the Jira tickets I created while on the trip.
I forgot to include the electric cooling fan update, since this was the hottest trip I've run with them. I hadn't done any of the items I'd thought about doing to improve the fan controllers shutting off when the fans were higher temp, so they were limited to around 60% PWM with an associated reduction in airflow vs. full on. In spite of this, the system overall was able to maintain temperature on the trip, including climbing the mountain going into Great Smokey Mountain National Park. I did have to pay attention to temperatures, but overall, it was manageable and worked well.
When leaving our campground from there (and climbing that same mountain the other way) I decided to run an experiment and leave the campground with the fans all going full blast just to see if that airflow could keep things cool enough to prevent them from overheating with the engine running at a significant load at any point. The answer was no, but what really got my attention immediately was how much more power the engine made. This isn't surprising of course, since it was forcing so much air through the intercooler. So an associated change I'm making is I'm going to add two pusher fans to the intercooler that will simply be on or off. These will serve to provide extra airflow when needed for cooling, but the big purpose will be for extra airflow through the intercooler, especially from a standing start. I'm going to have a manual switch controlled from up front for these, but am thinking about also adding a momentary switch for when I floor it to turn them on as well.
I completely get it, but there is irony in fan controllers that overheat.
No doubt. It's a complicated one, though, and I think it's more an issue with the fans than the fan controllers. Some of this is that I piecemealed the system together.
if I run the fans at full bore with the engine off, they go just fine, nothing gets hot to the touch. I tested this in my shop, it ran for 30 minutes like that.
The issue is that when you add the extra heat of the air coming off the intercooler and radiator, then the fans and controllers get very hot. When the controllers have an overdraw of current, they'll shut off and keep on trying to restart the fans. I found this during initial testing where I tried running two fans with one controller (they're set up so they can run two fans, but obviously two smaller ones). The fans would spin up, get going a bit and then shut off.
Once when the fans were shutting off on a previous drive, I tried just bypassing the controllers and powering the fans directly. I've done this once or twice before just fine, but at that point, I blew the fuse due to the inrush current being too high, indicating that the fans themselves draw more current when they get hot.
I'd used Dorman fans for this project, and af riend of mine who's a mechanic said he's had issue with Dorman cooling fans blowing fuses in cars when he's used them to replace broken OEM ones. So, it could be that it's a fan issue more than anything, and that's part of why I didn't want to relocate the controllers.
So long as I keep the current draw low enough when the fans get hot (the irony being that's when I need the most airflow) it's fine and everything works. I look at the data from the fan controller and it just does exactly what it's supposed to, running at whatever speed is necessary. But, the system requires some more tweaking. I think ultimately I'm going to want to get the Ford or C6 Corvette controllers that are set up for much more current than these Mazda ones (and cost more), but first I'll put the pusher fans on the intercooler, wire that up, and see what happens from there.
Solar controller just showed up. Oh my, this is larger than I expected. Good thing I have lots of space. Photo with my glasses for size comparison.
Cool on the solar charger! Re the fans, I'm not an expert, but I don't think that it's normal for electric motors to draw more current when they're hot vs cold. Any resistance change in copper wire vs temp shouldn't be significant at all. Either induction motors or brushed, doesn't make sense. For permanent magnet brushless motors, then maybe if the temp goes high enough to affect the magnetic field of the magnets? But that sounds like being right on the edge of the magnets failing and the insulation melting. Maybe the motor controllers run differently when hot...from memory, bipolar transistors conduct better when hot, but most new controllers are probably mosfet, and I think the conductance of those goes down with higher temp.
If the fans are just DC motors, then there may be a simple solution. Just put a thermostatic switch on the heatsink for the controller, and have that trigger a mechanical relay to lock the fans on. That'll take the load off the controllers, and power the fans full speed until the engine is shut down. Use a 2 pole relay, and have one pole wired to latch the relay closed once it's energized.
I can't say I've observed this behavior with fans before either, all I can tell you is that it's happening. The simplest solution (and one I've considered) is putting in relays that will either have them getting power from the controller or just direct power. I'm going to do these intercooler fans first and see how those go.
Wow. That's pretty big. Did you look at the Redarc stuff? I have no idea about price comparison, just know that people are installing it in Jeeps and 4Runners, so it has to be pretty compact.
It's definitely larger than I expected, which proves I didn't bother to read the dimensions which are clearly published.
I didn't really go for compactness. This is a bus, I have lots of room and can fit pretty much anything anywhere. The Renogy stuff seems to have good reviews and be reliable/durable/efficient, so I figure I'll give it a shot. Plus I found an Amazon deal.
I am excited to hear about the solar install.
Got the panels on the roof. Not drilled in yet, I wanted to place them and sleep on the layout before drilling any holes. I think I like this, though. Could be more compact, but gives me ample room to get around for maintenance.
I've spent a bit of time looking at the manuals for the charge controller as well as specs on the solar panels while doing my morning biking, trying to come up with an idea for how to set up the system.
The open circuit rating on the panels is 24.3V and the charge controller has a maximum of 150V. Theoretically, this means I could run 6 panels in series, and do two banks of those. That was my initial plan. If I change that to 3 banks of 4 panels in series, that gets me a bit more margin at under 100V input, and apparently the charge controller is more efficient at lower input voltages, although it's not a huge difference or enough that I'd be likely to notice.
I will need to buy a couple of fuses/breakers for this - notably 100A for the controller to the batteries, and then whatever ends up being the appropriate size for the panel to the controller, and that amperage will depend on whether I do 6x2 or 4x3 for wiring (need to decide that).
Besides how I want to wire the panels, I've got two other things I'm trying to figure out now:
1) Where to mount the controller. It's pretty big, and they mention that it should be mounted someplace with good ventilation, as it can produce a good amount of heat. It also shouldn't be mounted with the batteries. Both make sense, but that does limit my options a bit. I was thinking about putting it in the bay behind the batteries (this is where the inverter is right now), however none of the bays have much for ventilation, and that bay does get pretty hot from the inverter already. I'm thinking it may need to get put somewhere inside the RV, in a location that is in the path where I'll be running the wires.
2) If I need to add in any sort of protections or interconnects for its use with the generator or alternator potentially charging as well. My understanding is that no, it won't. It's a smart device that will kick off if voltage isn't where it should be. The inverter/charger connected to the generator is also smart (although they don't talk to eachother). The alternator is dumb, but still has a voltage regulator so it shouldn't overcharge things. But it would be good to make sure of that.
Overall, the hardest part I think is figuring out mounting. Since controls are on the controller itself, it should be someplace easily accessible such that I can see what it's doing and adjust it. It has optional modules for extra communication, but I'd rather not buy those.
Manuals for those interested:
Are there any other reviews/photos of similar applications that you could use to select a good location for placement of the controller? I would think the bays would be fine. Not "ventilated" as far as air exchange, but surely they just need enough space to allow heat transfer. It would also keep the higher gauge cable runs shorter being close to the inverter/batteries.
I agree, it would be best to keep those runs as short as possible. I'm going to dig some more before making an official determination.
Maybe some fans for the controller?
For the solar controller or the fan controllers?
Only thought I have is that the controller(s) have to run over a wide range of input vs output voltage/current, and they're probably not all that efficient over the entire range. So they're potentially give off quite a bit of heat. If you put them inside, you're going to have to remove that heat via AC in the summer. If possible, I'd try to hang them outside somewhere, unless you mostly camp in cold weather.
But it was a quick thought on the solar controller. I’ve set up server racks in closets with a vent at the bottom of the door and a set of really small muffin fans at the top. Enough to change the air in the closet a few times an hour. Something like that might do wonders for the solar controller in an otherwise enclosed space.
I agree. In the bays is better.
That would be a potential for sure. I already know that the inverter makes a good bit of heat (and has its own cooling fan), but I also know that just having that fan blow into the bay will cause it to get hot.
The way the bays are set up, I could get a hole saw and drill some holes, put in a little computer fan, with a thermostatic switch, and that would probably be enough. I'll look at it more.
This is what ya need.
I was thinking about converting an HEMTT. Remember we like motor homes, not camper trailers.
I like it! If that has remote tire pressure control, you might be able to rig it up to self-level when you park.
The important thing is intake at the bottom and exhaust at the top so convection works for you. Cross from front to back or vice-versa is a plus.
Yesterday was the day I was supposed to work on the RV and get at least a lot of the solar system installed, if not wired. Not surprisingly, that didn't quite work out. The brackets that came with the solar panels came with had self-tapping screws which, not surprisingly, stripped out in the fiberglass. So I'll go the better but higher effort method of rivnuts, and since I had rivnuts but not the appropriate 10-24 screws, I decided to just work on other items and save the panels for a time when I could do the rivnuts and put the screws in to get at least most of them down.
The 100A charge controller really is large, and trying to meet the install requirements isn'tsuper feasible because of its size. It would be fine in a home, but in an RV where you tend to have more space constraints, it's harder. I still want to stick with it, but it may require some more inventive approaches to mounting and cooling to make it work. Here's a picture to show rough idea:
The battery bank is to the right in the picture, and then another bay (which houses the inverter as well as general storage) is probably the best place to put it. The requirements are that it be mounted vertically (although I think this is more for natural convection purposes than anything) and 6" clearance above and below for airflow. And it's supposed to not be in the same compartment as the batteries, and have ventilation.
At this point, I'm figuring I'm going to have to move some batteries to that rear bay and annex it for battery use. I'm not sure which bank I want to move, and then which bay I want to put the solar controller in, so I need to figure that out. I looked around inside and there's really no place to mount the thing without completely annexing some storage, and we use all of it right now. After all, there's 5 of us. I could put it in the master closet but I don't like that for a lot of reasons.
I did make progress elsewhere though, mostly just on little things. I got the new house water pump installed which is both quieter and higher flow/pressure. The inlet screen I didn't buy at the same time and should have, so I got one of those coming and will replace it later this week.
I also got the pusher electric fans on the intercooler. That would've been a whole lot easier to do when the intercooler was not installed, but oh well, I got it done. Relays, switches, and wiring should come today, so I'll get that all taken care of sometime this week. I think that will be the most noticeable (well, probably only noticeable) driving improvement for our next trip.
I've got two lighting issues that are annoying me. After converting the marker lights to LEDs, I found the side markers which are both markers and turn signals only worked properly with the side marker lights on, they didn't work properly without the lights on. So I figured that he reason was because the system would invert which side of the wiring was ground vs. positive, which was correct, and so I was going to wire it up with some diodes and a dedicated ground. The problem is that with the side marker lights on, the +12V comes from one wire constantly, and then the ground is what gets interrupted for blinking. So this essentially inverts my problem. I may just revert to incandescent for the side lights since that's simple, and use the smoke lenses to match the rest of the lights.
The other issue I'm having is that the brake lights are now coming on whenever the marker lights are on (I haven't tested if the reverse is the case as well, but need to). This one is puzzling me more, since it seems that this would be a short within one of the sockets or wiring of the new taillights I put in that is connecting the marker lights to the brake lights on one of the bulbs, or maybe a bad ground that's causing current to flow through the brakelight side of a bulb within those taillights. Pulled all the taillights and all the bulbs, still does it. I need to do some more diagnostics there and think about what else could be causing that, although I can't think of any other area where the tail/marker lights and the brake lights intersect electrically. This one is a weird one.
I cant tell in that picture, but can you mount it to the ceiling of the bay?
Totally off-topic for what you’re doing now, Ted, but an acquaintance of mine had a fire in his battery bay…the gas strut on the door came loose and fell across the battery terminals. I know you know this, but make sure those struts are secure.
I could, but that would be really impractical. Then I'd have to look upsidedown to adjust it. It would require some sort of forced air flow, but I think I may be there anyway.
I feel like this is the perfect chance to mold up a P-51 belly scoop under that bay . . .