The stock dining table on my 2023 Safari Condo (SC) Alto F1743 was coming unmoored from the base. I tightened the screws a couple of times but they just loosened back up and a couple were stripped. I also discovered the pedestal flange was cracked at one of the screws.
I did a quick search for this pedestal flange at Camping World hoping to find something local but didn’t. There were many possibilities on Amazon and this one seemed like a direct replacement. It does look identical– thin aluminum with chrome plating. And just as likely to crack, so good that it came with two pieces so I have a spare. But the hole pattern is slightly different as shown below. It isn’t that SC just drilled the holes slightly wrong– when the old and new parts are placed back-to-back the difference is obvious.
Slightly different hole pattern
I wasn’t sure what the material of this base board was until I began drilling into it. Some theories were an outer veneer around particle board or high density foam. But I think it’s actually plywood with a veneer. I’m not a fan of using wood screws to fasten the pedestal flange to any of these materials given how much force it sees when sliding that table back and forth or bouncing down the highway. My original thought was to use through-bolts but that would require counter-sinking on the bottom to recess the bolt head so the base board will still slide along the floor.
A helpful Altoiste recommended using T nuts. Brilliant. I wasn’t sure if they would recess enough to allow the base board to still slide but gave it a try. They work beautifully. The aluminum bracket on which the base slides is slightly thicker than the exposed edge of the T nut, so it still slides.
T nuts protruding on the bottom
I used M5 T nuts and M5-0.8 16mm stainless steel flat head socket cap machine screws. The holes in the pedestal flange have a counter-sink taper. I think the taper in the screw head better matches the pedestal flange than the round-head screws with no taper that SC used and may be less likely to crack it. A 16mm screw length uses all of the threads of the T nut without protruding past the edge. To install the T nuts I used a long M5 bolt through a piece of scrap aluminum and tightened the nut until it was pulled tight against the base board. Note the picture below shows a 12mm screw length, before I switched to 16mm.
Machine screw and T nuts
The trim around the edges of the base board is offset so the original bottom was flush with the board and the top had some trim overhang. I figured this must have been intentional so mounted the pedestal flange on the same side. I now think it probably doesn’t matter. Because the hole pattern was slightly off I couldn’t just drill out the the existing holes so I used the new pedestal flange as a template. I drilled out one existing hole and secured the flange with screw and T nut, then drilled the remaining holes through the flange. I thought I might destroy the flange in the process so was happy to have a spare, but it survived. It might have been a better idea to simply rotate the pedestal flange and drill entirely new holes, but this worked.
In the final assembly I added blue thread locker to the machine screws. I also considered adding adhesive between the base board and pedestal flange. SC had used some sort of silicon adhesive but I don’t think it really adhered– I had no trouble separating the two parts. I decided against adhesive. I don’t think the combination of T nuts and machine screws with thread locker will be coming loose any time soon and I don’t want to make things harder if I ever need to revisit this. I think the weak point now is the pedestal flange itself.
When I initially disassembled the table I had a hard time separating the table leg from the bottom pedestal flange. I ended up unscrewing the flange and banging it off with a rubber mallet. I don’t know if it will help but I added a tiny bit of ant-seize compound to both the bottom and top of the table leg. We never convert the table into a bed so not a big deal for us if it seizes again.
Today I flipped the shades on the Big Front Window (BFW) so that the blackout shade is on bottom and the bug screen is on top. I did this to improve airflow between the shades and the window in an attempt to avoid excessive heat buildup that could warp the window, apparently a thing with the BFW. The idea is to set the shades for 80% blackout on bottom and 20% bug screen on top and use convection (hot air rises) to vent heat buildup out the bug screen on top, pulling in cooler air at the bottom to replace it (crack open the BFW). Then aid the process by pulling out the hot air with the trailer’s roof fan. This helps keep the interior of the trailer cooler without cooking the window in extreme conditions. The orientation has the added advantages of somewhat increased privacy when partially deploying the blackout shade and putting the heavier blackout shade on the bottom where the wall is more vertical, reducing the tendency for the shade to sag.
Flipped, in convection mode
All of the shades in earlier Altos were oriented this way but sometime before my 2023 F1743 was built, Safari Condo (SC) began flipping them on all of their trailers. SC confirmed that Horrex is the manufacturer of my shades. The Horrex manual clearly states that the blackout shade should be on the bottom. SC told me the orientation is personal preference and that they flipped them for convenience. That doesn’t make a lot of sense to me considering the guidance from the manufacturer and the considerations listed above, but OK. Easy enough to flip them back.
And it was pretty easy. I was initially unsure whether the curvature in the frame is symmetrical but it clearly is. This means I could flip the entire assembly, frame and all, vs. swapping the cartridges that hold the blinds. It took me about an hour to do this job solo. A second person might have helped or more likely would have just been in the way. Judicious placement of seat cushions and pillows doubled for a second set of hands. Here are the steps:
Remove the front table
Pop off the four plastic covers at each corner of the frame by pulling them from behind
Prop the bottom of the frame with cushions and pillows to keep it from flopping down when screws are removed. The top of the frame is held in place by two brackets so it stays put without the screws.
Remove the two sheet metal screws at each corner that secure the frame to the wall of the trailer.
Carefully slide the whole frame up slightly to detach the top frame from the brackets. The clearance between the frame and the light switch assembly is tight, I had to “bend” the switch assembly slightly to free the frame. There is enough natural play in that assembly, nothing was bent permanently.
Carefully rotate the whole blind assembly 180 degrees. The frame is fairly solid when detached from the wall but can’t withstand too much sideways force.
Hang the top of the frame on the brackets, again “bending” the light assembly slightly. Prop up the bottom of the frame with cushions and pillows to hold it to the wall of the trailer.
Re-attach the two sheet metal screws at each corner. As with every other sheet metal screw in this trailer, be careful to avoid stripping it while tightening. So.many.sheet.metal.screws :(.
Replace the plastic covers at each corner. The trick is to slide the pointy part of the cover over the inner corner of the frame first, then push it on the rest of the way from the outer part of the frame.
Reverse the plastic clip that joins the two shades
Behold the now upside-down and out-of-sight warning label
Two sheet metal screws at each cornerTight clearanceProp bottom with cushions and pillowsRemoved, ready to rotateBracket, one of twoBrackets
If I had stripped one of the sheet metal screws in this process I would have replaced them all with rivet nuts and stainless steel machine screws. If I had the rivet nuts on hand I would have done this proactively, but I was impatient.
Rather than “crack open” the window using the built-in detents on the left and right latches, it has been suggested more airflow is needed, maybe a 1/2″ to 3/4″ gap. It’s difficult to measure but using the detents, the gap between window and seal seems slightly less than 1/2″. A fellow Altoiste pioneered some blocks that will hold the window out further. These would be simple to create and could potentially hold the window more securely: Three attachment points instead of two, at the bottom of the window instead of the sides, and more difficult to break in from the outside. Here’s a post showing his design https://www.facebook.com/groups/Altoistes/permalink/1204161736285064. And another where STL files were uploaded that can be used to 3D print the spacer blocks. https://www.facebook.com/groups/Altoistes/permalink/24523360507271858
Now I need to decide if I want to flip the remaining windows. My biggest concern was the BFW because I sometimes close the blinds while parked at home. I generally don’t close the other blinds and I don’t imagine the smaller windows are as susceptible to warping, but the same convection mechanism would apply. I’m not as concerned about the privacy aspect. I’ll probably flip them eventually.
I’ve read about concerns with flipping the kitchen window because of the tight clearance with the overhead shelf. Based on this experience, I don’t think it would be an issue, at least for my F1743. The frame doesn’t have to slide up much to detach from the brackets, it looks to me like there is enough clearance. And I would imagine the blinds went in after the shelf when the trailer was constructed.
The project is complete. It went pretty close to plan, details below.
Electrical Redesign
My original motivation for the electrical redesign was to include the caravan mover in the Victron battery monitor. Once I dug into it I corrected a number of additional issues, including
Moved the battery cutoff from the negative to the positive side of the circuit for better isolation / safety.
Reduced wiring to the battery from three circuits to one. In doing so, upgraded the inverter wiring from 1/0 to 2/0 gauge wire to match the 275A fuse protecting it and made branch circuits out of the CM and original DC distribution panel, relegating the latter to a subpanel. Added the Blue Sea Systems DC distribution panel to manage all of the charging loads (inverter/charger, auto, and solar) as well as the new branch circuits. I decided to pull inverter power off of the main positive terminal of the Blue Sea panel rather than from one of panel fuses and rely on the 275A breaker in the battery box for protection. The stud housing isn’t really designed to handle two 2/0 connectors, I had to grind off some of the cover for it to seat properly in this area.
Added a CNLonQcom isolator switch for the rooftop solar for better isolation / safety and easier winterization. The switch comes with the connectors installed on the wires but you don’t need them, they would just take up a lot of space for nothing more than another potential failure point. I removed the connectors from both ends (4 total). One set of leads was long enough to reach the Victron solar controller so I connected them directly. I butt-spliced the other set to the solar leads coming from the roof with 8 gauge waterproof crimp-style butt splices. Waterproof is overkill inside the trailer but it’s what I had.
Increased the DC ground bond wire to 2/0 gauge to accommodate the current that the system can supply.
Moved the breakaway circuit to its own fuse for reliability and to aid in troubleshooting. Also moved power for the Victron shunt to its own fuse. These changes were made possible by the addition of the Blue Sea Systems fuse panel. It was pointed out to me that SC may have lumped Outlets and Breakaway into a single circuit not because they ran out of circuits in the distribution panel but as an indication that the circuit has blown. This makes some sense because there is no outward indication that the breakaway functionality is inoperative. The idea is that it will be obvious that the outlet is blown and the user will be incented to replace the fuse, incidentally fixing the breakaway functionality. On the other hand if the customer is starting the debug process by noticing the breakaway isn’t working, it requires reverse-engineering SC’s electrical design. I guess I’d be OK with this if they actually documented it.
Got rid of a surprising number of unnecessary splices, particularly in the CM circuit.
And an astonishing amount of unnecessary wire. The most egregious example was over 20 feet of bundled telephone cord, half of which was inexplicably covered in plastic wire loom, eliminated with two simple RJ11 crimps. A service loop is one thing but this was pretty nuts. All told I removed nearly 4 pounds of wire and there are still plenty of opportunities to remove more.
Replaced connectors to match the studs to which they connect. Many of the original connectors were oversized (3/8″ terminal on a 5/16″ post).
Added a roughly 8″x8″x1/8″ aluminum plate onto which I mounted the rooftop solar controller, battery cutoff switch, solar cutoff switch, inline fuse for TSC, and 2-circuit AC breaker box.
The Blue Sea Systems fuse panel, shunt, shelf, and some of the aluminum plate were mounted using M5 rivet nuts. I flipped the shunt 180 degrees to achieve slightly better cable routing.
Aluminum Plate for MountingNew AC and DC distribution
Functional Changes
In addition to the above improvements I added the following new functionality.
Tuson Sway Control (TSC)
I first had to choose a location for mounting the main unit. The Tuson installation video doesn’t really address a trailer like the Alto but there are several obvious choices, each with advantages and disadvantages.
Location
Pros
Cons
Under belly of trailer
* SC’s location (I think)
* Very exposed * Mounting most difficult * Wiring most difficult
Under front skinny cushion
* Easiest wiring * Completely protected
* Mounting more difficult * Uses valuable space
Behind battery box
* Easiest mounting * Mostly protected * Uses otherwise wasted space * Not mounting to trailer skin
* Must waterproof connections
I wanted to avoid mounting it underneath the trailer for the reasons listed above. The way SC brought the 7-pin wires inside the trailer made alternative mounting locations very easy. I decided to mount it to the battery box because it’s extremely solid, perfectly vertical, and doesn’t take up room inside the trailer that could be used for other things. This thing is designed to be mounted outside the trailer so I’m not too concerned about weather and this spot on the back side of the battery box is about as protected as could be without being inside. Another reason for picking this location is that I’d prefer not to mount directly to the skin of the trailer wherever possible. And this would be a somewhat funky mechanical mount under the front skinny cushion since the trailer wall isn’t vertical in this location.
Next I had to figure out how to get the wires from the unit to the fuse box and 7-pin wires inside the trailer. This was an easy decision: the overall electrical redesign freed up the wiring running from the caravan mover to the battery box. I couldn’t use the wires themselves, they were too few and way too big, but the existing routing led perfectly from under the front skinny cushion to where I mounted the the unit on the back side of the battery box.
Finally, I had to find the power, ground, and the brake control signal coming from the TV and going to each wheel. SC made this super easy by bringing all the 7-pin wires, as well as the wires running to the brakes at each wheel, inside under the front skinny cushion. They enter on the right (passenger) side of the trailer (see picture below). The wire loom marked with green and yellow tape are the brake control signals going to the left and right wheels, respectively. There is corresponding colored tape at each wheel. The blue wire is +12 Vdc coming from the Outlets circuit in the fuse panel and goes to the breakaway switch outside the trailer.
7-pin connector wire bundle entering the trailer
Peeling back the larger wire loom on the right revealed the individual wires. From top to bottom (only a few of these are needed for sway control):
Yellow – Auxiliary (capped)
White – Ground
Blue – Brake control
Splits to the left into left and right brake control signals routed to the wheels
Splits to the right to the breakaway switch
Red – Left turn / stop
Brown – Right turn / stop
Black – +12 Vdc
Green – Tail lights / running lights
Splits to the left to trailer lights on each side of the trailer
Blue – Power from the trailer to the breakaway switch
Individual 7-pin wires inside trailer
I’m not a fan of pulling power for the breakaway switch from some random circuit like Outlets. I can see why SC did it– they ran out of slots in the fuse box so they picked a circuit that was fused appropriately (15A) for the 14 AWG breakaway wire. But this decision complicates troubleshooting electrical issues. If a DC outlet pulled too much power and blew the fuse, the breakaway functionality would be inexplicably (and silently) broken as well. With the addition of the SafetyHub 150 fuse box I have no such limitation. I decided to move the Solar circuit to this new panel and repurposed the Solar fuse in the original panel for the breakaway line. Rather than dedicating a circuit to the breakaway, I should have pulled power from the TSC circuit. That way, the TSC LED will indicate when both TSC and breakawayfunctionality are inoperative. I’ll make that change eventually.
Testing the system was challenging. The proper way to test, per Tuson instructions, is to short signal and ground at each wheel and note the number of flashes on the LED to confirm continuity and the correct side (left or right wheel). However to do this I’d have to disassemble the wheel that had just recently had its bearings repacked. I wasn’t willing to do that so instead I pulled the breakaway switch and verified the brakes engaged on both wheels, by jacking up each and attempting to rotate it. This verified that the brakes were getting the brake signal but not the left/right distinction. For this I made sure I was connecting the SC green signal to Tuson purple (left) and SC yellow to Tuson pink (right). And I hope SC’s labelling is correct. So far so good on a recent shakedown trip.
An annoyance of the Tuson system is that there is no indication that it’s doing anything on power-up. It’s designed to “wake up” when it sees the trailer brake signal from the TV but my TV was nowhere near when I wired this up. Fortunately pulling the breakaway switch kicks it, revealing the pulsing green LED that indicates all is well. Of course this still doesn’t tell you if left is left and right is right.
Indeed, that funky LED provides the only, very limited, visibility into what the system is doing. If I had learned about the Curt system earlier I might have opted for it because it uses a Bluetooth connection to provide this visibility. I assume it provides a lot more detail as well but I have no experience with it. But I chose the Tuson and now had to figure out where to mount the LED and how to route the cable. My original thought was to bring the cable inside the trailer along with the other wires and sneak it back outside where the driver-side front-facing trailer light is attached. Then mount the LED to the metal strip directly above the trailer light. This approach however looked too messy. Instead I kept the cable outside the trailer and poked it under the coroplast, routing the cable between it and the skin of the trailer. I mounted the LED to that same metal strip above the trailer light using two pop rivets. The connector provided by Tuson was too bulky to fit under the coroplast so I cut it off and spliced the wires together with solder and adhesive (waterproof) heat-shrink. This location for the LED proved to be perfect– easy to see from the Tesla driver-side mirror and rear camera.
TSC sway controller at rear of battery boxCM cabling replaced with TSC. LED cable in center. Also TPMS cable (not visible) joins near the tiedownTSC Sway LED
Tire Pressure Monitoring System (TPMS)
This installation was relatively simple. While sitting over the winter the stem on one of the tires failed so I had Discount Tire install the ball sensors when they replaced the stems with a (hopefully) beefier design. The stems were inexpensive and they didn’t charge for the sensor installation since they had to remove the tires from the rims to replace the stems.
It’s possible that with such a small trailer I wouldn’t need a signal repeater but it came with the kit and I was overhauling the electrical system anyway. Underneath the propane bottles seemed like a natural location and made it easy to route the cable to the wire bundle for the sway controller and inside the trailer. The current draw is very low but my goal is for every load to be accounted for by the battery monitor so I wired it into the Blue Sea Systems fuse panel.
One (minor) reason I chose the Tuson system over others is that in addition to tire pressure and temperature, it reports the voltage of the trailer battery. But I forgot that I already have that information on my phone from either the Victron BMS or solar controller– the Bluetooth signals make it inside the cabin of the TV just fine. Oh well, it’s like having a clock in every kitchen appliance, each reading a slightly different time.
In our shakedown trip the TPMS system worked well and I think will be very reliable.
I’m not sure yet what portable solar panel I will purchase. I’m eying 220W panels as well as a new modular 500W panel from EcoFlow– this choice will determine the solar controller I’ll need. We don’t have any boondocking plans this season that need the additional solar power so we’ll probably purchase the panel and controller next season. But while mucking around with the trailer wiring I might as well install the connector and bring the wires to the location I plan to install the controller.
The electrical redesign freed up a pair of 8 AWG wires running from the batteries to the original fuse panel. The battery box is a perfect place to install the external solar connector and the controller will be installed near the fuse panel so I just re-used the wires– pretty simple. 8 AWG is overkill but doesn’t hurt anything, will just have to crimp on a short section of 10 AWG wire for the connector. Removing the CM wiring left a hole in the battery box just slightly too small for a waterproof bulkhead PowerPole connector so I used a step drill to widen it and installed the connector. For now I’m leaving it unconnected.
External solar controller will probably go somewhere right of Blue Sea fuse panel
Inverter Power for Outside Outlet
This was a fairly simple change. Instead of running the inverter AC output directly to the microwave/outlet #1 rocker switch in the kitchen, I ran it to a new 2-breaker housing. I ran a 20A circuit in that housing to the microwave/outlet #1 switch to achieve the same functionality as before. And I moved the source of the outlet under the front table from the original AC breaker to a 15A breaker in this new breaker box. This circuit also feeds the driver side external outlet, giving me inverter power for both. Because worst-case it’s possible for this new breaker box to draw more than 20A, I beefed up the Romex from the inverter to 10 gauge.
The hardest part of this mod was wiring the miniature breaker box. This thing was just barely big enough to handle the necessary wire and connectors. Bringing 10 gauge Romex into the box didn’t help. I used Wago connectors instead of traditional wire nuts, I don’t think this would be possible with the latter.
2 Circuit Breaker Box
Finished Product
Here are some pictures of the completed project.
Battery box. Negative wire long enough to reach left battery to aid in balancing. External solar connector.Main DC circuit, external solar connector, TSC sway controllerDriver-side access. Battery cutoff, solar cutoff, inverter breaker boxSome of the removed wire
Lessons Learned
I love the mechanical design and build quality of the Alto trailers. Factory electrical, not so much.
Curt sway control might have been a better choice than the Tuson system. I prefer the Tuson’s mounting requirements (funky LED aside) but would like more visibility into what the system is doing. I’m not convinced differential braking is as important as Tuson claims.
If I were to go through this exercise again I might move the location of the smart shunt to free up some space around the other components. And probably raise the solar controller a bit. Digging back in to some of these components is a bit of a pain.
Upgrading the solar controller from Epever to Victron was well worth it. The Victron is a joy to use, beginning with a solid, compact mechanical design and ending with a rare example of a well designed phone app. It’s so much better that I won’t try to sell the Epever because in good conscience I’d have to recommend purchasing a Victron instead. I can’t think of a reason why you’d ever want to choose the Epever even as a replacement if the original died. But if someone wants this thing, let me know.
One down side to running all the DC power through a single 2/0 gauge cable pair is that under maximum inverter load, there is enough voltage drop to noticeably dim the LED lights. I see this when running the induction stovetop at full power. A microwave would do the same. The Xantrex and other electronics don’t seem to mind. I’ve yet to measure the drop.
Wiring Diagrams
Parts List
Doesn’t include probably a couple hundred additional dollars in miscellaneous small parts and tools. I had a lot of the necessary tools including the rivet nut setter and smaller crimpers / strippers but purchased a hydraulic cable lug crimper for the big wires and a label maker.
By ordering sway control and TPMS at the same time, I met Tuson’s $1,000 threshold for receiving a 25% discount. This discount was a pleasant surprise, it’s undocumented as far as I can tell.
We recently acquired a 2023 Safari Condo Alto F1743 travel trailer. This is essentially the same trailer we rented a couple of years ago but with even more factory options. We pull it behind a 2023 Tesla Model Y Long Range EV. The installed options that impact the electrical system include
Television w/ Furrion external antenna and wifi booster
Additional AC and DC outlets
At Rest
Had I opted to purchase the trailer new I wouldn’t have chosen the inverter option. It’s costly, heavy, and of limited practical use, especially with no microwave installed. But now that I have it I plan to keep it. It will be useful for charging e-trike batteries and powering a future single-burner induction stovetop or maybe an induction water kettle. And who knows, we may miss the microwave. It could also charge the EV, though with only 200 Ah of battery storage it can’t charge it much.
There are still three options missing: External solar, electronic sway control and a Tire Pressure Monitoring System (TPMS). In my effort to add these features I encountered some issues with the existing electrical design and decided to resolve them at the same time.
Much of what I’m doing here is based on prior work by pioneering Alto owners, helpfully documented on the Altoistes Facebook group. Thanks to all. Here’s the result of my effort: Alto F1743 Upgraded.
The Issues (in no particular order)
The installed Victron Smart Shunt does not capture the current drawn by the Caravan Mover (CM) so it’s use is not accounted for in the State of Charge (SoC) measurement. I plan to use the CM often to avoid backing into tricky camp spots, optimize the position of the trailer in the spot, and save the EV battery for getting us back to civilization. Once settled in camp I’d like to know how much charge is left on the trailer batteries but the Victron will read too high in this scenario.
The battery disconnect switch (big red handle) is on the negative side of the circuit, leaving some of the circuitry at 12VDC even when “off”. This doesn’t leave any of the components energized because the ground path has been disconnected but it does make it easy to find both 12VDC and ground when poking around, a safety concern.
There is no solar disconnect switch, leaving the solar controller energized whenever the solar panels see light, even when the battery is disconnected. In addition to the safety concern, when the battery is disconnected the Epever solar controller emits wildly varying and out-of-spec voltages which can damage trailer electronics. The workaround is to pull the solar fuse before disconnecting the battery but this is a pain and can cause a spark, especially when reconnecting. And the solar controller remains needlessly and confusingly energized.
At only 8 AWG, the wire connecting DC ground on the distribution panel to the trailer frame seems inadequate. In the event of a fault it should be able to handle the same current supplied on the positive side of the circuit. So 1/0 gauge (or really 2/0, read on..).
It seems that SC adds options incrementally, which leads to overly complicated electrical wiring. For example the base configuration includes 8AWG wire between the battery and the DC distribution panel. When the inverter option is added, separate 1/0 wiring is added from battery to the inverter. When the CM option is added yet another set of 5 gauge wires are added. And as far as I can tell the CM wires are installed as configured in the Truma installation kit, without cutting them to an appropriate length. All this creates a jumbled mess inside the battery box and elsewhere. This can all be consolidated into one set of 2/0 wires.
The wire supplying power to the breakaway switch is connected to the 12Vdc Outlet circuit. This is kind of gross, it means if I plug something massive into one of the 12V outlets and blow a fuse, my breakaway switch is (silently) inoperative. I can see why SC wired it this way– they were out of fuse slots in the distribution panel and the 15A fuse for the outlets is appropriate for protecting the 14 gauge wire for the breakaway switch. By adding a second fuse panel I don’t have this problem, better to give the breakaway switch its own circuit. I’ll include power for the TSC sway control on this circuit– these two circuits are related and less likely to interfere with each other. It was pointed out to me that SC may have lumped Outlets and Breakaway into a single circuit for a different reason: as an indication that the circuit has blown. This makes some sense because there is no outward indication that the breakaway functionality is inoperative. The idea is that it will be obvious that the outlet is blown and the user will be incented to replace the fuse, incidentally fixing the breakaway functionality. On the other hand if the customer is starting the debug process by noticing the breakaway isn’t working, it requires reverse-engineering SC’s electrical design. I guess I’d be OK with this if they actually documented it.
The inverter circuit is connected with 1/0 AWG wire. Not only is this inadequate if the inverter is ever asked to deliver 2000W, the 275A fuse protecting the wire is too large, another safety concern. This is an even bigger issue with my plan to consolidate three battery connections (inverter, caravan mover, and DC distribution panel) into one.
Many of the high-current DC cables connect to M8 (roughly 5/16″) posts with M10 (roughly 3/8″) connectors. This results in significant slop that can compromise the connection and should be avoided.
Inline fuses. There’s one for shunt power buried somewhere in the rat’s nest of wires under the front skinny cushion and another for the CM in the jumble of wires inside the battery box. The problem with inline fuses is that it’s difficult to know they even exist, adding an unnecessary challenge to troubleshooting electrical problems. Bonus: power for the DC distribution panel is protected by a nearly invisible fusible link inside the battery box. All the disadvantages of an inline fuse, and more! There is still another fuse inside the battery box for the inverter circuit. This is a big fuse and would be appropriate and expected if it protected a single feed for all of the DC subsystems, but as-is it’s just another unexpected inline fuse.
Factory Wiring
Battery BoxUnder the Front Skinny CushionCaravan Mover, Battery Cutoff, InverterInverter, viewed from outside the front left hatch
The picture below shows the back of the battery disconnect switch (big red handle), wired on the negative side of the circuit. The big cable on the left goes to the battery side of the shunt. The big cable on the right goes to the negative battery terminal, for the inverter circuit. The red crimped cable goes to the negative battery terminal, for the DC distribution panel. The yellow crimped cable eventually splits into two wires, one for each electric trailer brake.
Battery Disconnect, Shunt
The following picture shows the Smart Shunt. The bottom terminal is the battery side and connects to the left terminal on the battery cutoff switch (see picture above). At the load side terminal on top there is a big cable (hidden) that connects to the inverter. The smaller black cable (visible) connects to the DC distribution panel. The white cable (with broken strands) connects to the solar controller. The small red wire is power for the shunt electronics.
Smart Shunt, Broken Strands on wire to Solar ControllerNo MicrowaveFactory AC DC Distribution Panel, solar fuse removedFactory AC WiringFactory DC Wiring
External Inverter Outlet
From the factory, Altos are configured so that the inverter can supply AC to only the microwave or a single kitchen outlet. As long as I’m lugging this inverter around it would be nice to be able to power something outside the trailer. The only something that currently comes to mind is the EV and for that the driver-side outlet would be best. This is pretty easily achieved by just moving the Romex supplying outlets #3 and #5 from the 15A Outlet breaker to the output of the inverter, with appropriate breakers for it and the existing microwave/outlet #1 circuit. And beefing up the Romex feeding the breakers from 12/2 to 10/2 AWG since it could now carry as much as 36A if both circuits are maxed out. With this change both the GFCI outlet under the front table and the downstream outlet on the driver-side trailer exterior will be able to be powered from the battery.
I know, charging an EV from 200Ah of battery is hardly worth the effort. I figure it would yield something south of 10 miles of additional range and leave the trailer batteries completely drained. But with 220W of rooftop solar, 500W of external solar, many days of a lot of sun, and a small animal sacrifice it could make sense in a pinch. Maybe more battery some day? Who knows. But I only have to do it once to claim my ride is solar-powered.
External Solar
When at camp we’ll do our best to park the trailer under shade. To compensate for the reduced solar production we’ll deploy a portable solar panel, yet to be purchased, probably in the 220-500W range. Since the panels produce higher voltage at less current than the 12V output of the controller, it’s more efficient to place the controller close to the battery rather than at the panels. More efficient because there will be less voltage drop over a potentially long run of wire between the panels and the battery. With 220W panels for both rooftop and external solar, I could get away with Victron 75/15 controllers for all practical purposes. But 100/20 gives me a little more headroom at a modest increase in size and cost. Replacing the Epever controller with Victron just about makes up for the second solar controller in terms of space. I also prefer Victron over Epever in general.
Sway Control
The trailer came with a Reese weight distribution hitch. I didn’t use it on the initial trip home from where we purchased the trailer in Michigan because the bottom portion was too close to the ground when connected to our tow vehicle, a 2023 Tesla Model Y Long Range. It could be made to work by lopping off the unused bottom portion of the hitch but I plan to remove it. WD hitches work by transferring weight from the rear axle of the TV to the front axle and trailer. This can indirectly help address trailer sway by improving traction on the TV front steering wheels. But WD hitches add stress to the TV frame, something many car manufacturers discourage, and don’t directly address trailer sway. With trailer GVWR less than half the weight of the tow vehicle and hitch weight less than 350 pounds, the benefits of WD are likely minimal and come at a high cost in terms of weight and complexity. Complexity in hitching/unhitching is a bigger deal with an EV since many chargers require dropping the trailer and we’ll be stopping more often than with an ICE TV. This is one of the reasons we chose one of the lightest trailers available, we plan to take advantage of it.
Some WD hitches (not mine) specifically address trailer sway but this adds even more weight and complexity. Electronic systems available from Tuson and Curt provide better sway control than mechanical systems with no cost in terms of weight or complexity. If the trailer is loaded properly, electronic sway control might be unnecessary with this setup but it’s essentially free insurance after the initial $.
I chose Tuson over Curt because it integrates more cleanly with the trailer. It also controls the brakes differentially instead of applying the same control to both brakes. Tuson makes a big deal out of this but I’m not convinced it makes a big enough difference to warrant the increased cost and install complexity.
Tire Pressure Monitoring System
Another in the category of cheap insurance. Every account of trailer tire blow-outs I’ve heard of involved expensive damage to the trailer wheel trim, etc. Behind an EV I’m not sure how long it would even take to notice a problem back there.
I considered several TPMS systems that put the sensor on the end of the wheel stem. They’re relatively inexpensive but don’t get high marks for reliability or battery life, though the batteries are at least replaceable. The weight of the sensor puts stress on the stem, the source of some of the reliability concerns. They can also complicate adding air to the tires.
The Tuson system is more expensive but uses automotive pressure/temperature sensors where the bulk of the sensor is inside the wheel. These should be as seamless and reliable as the sensors in the TV and last about as long (Tuson estimates 5 years). Probably longer since the trailer is used a lot less than the TV, which is also our daily driver when not travelling. However like the TV, the battery in the sensors can’t be replaced. Another benefit is that the Tuson repeater transmits trailer battery voltage in addition to tire pressure and temperature. This is useful for us since the TV doesn’t charge the trailer battery. We’ll be relying on solar to keep the 12V compressor ‘fridge running while on the road.
In addition to traditional automotive sensors that attach near the stem, Tuson now offers “ball” sensors. The same electronics packaged in a small plastic ball that weighs almost nothing. Pop the bead on the tire and drop the sensor inside where it rattles around until quickly pinned to the rim perimeter. Installation is easier though I probably won’t benefit because I’ll need a tire shop to install them anyway. But intriguing enough to give it a try.
It’s a little annoying that the smallest package Tuson appears to offer has four sensors. I only have two trailer wheels. But my brother has two more wheels on his trailer, thinking I’ll just give him the extra sensors, who knows how much battery life they’d have left after the originals die. All he’d have to purchase is the receiver initially, if he has communication problems he could then purchase the repeater. Tuson conveniently sells them separately and the net cost would be cheaper than what I paid initially.
A Seasonal Commute 