Aluminum Camper Forum

That looks great!  You may have just given me the inspiration to give this a try.  Thanks for sharing!

I ran into a slight issue when crimping connectors for the solar panels.  Most of the MC4 connectors are only good for #10... I was not able to find one for #8 AWG.  I was intent on using #8 AWG wire, so that I could place the solar panels further from the camper.  However, I discovered that the crimp tool that I used for #8 lugs (going between components) did not produce as good a crimp on the #8 MC4 connectors for the solar panels.  The metal in the MC4 connectors is a thinner than that in lugs, and the resultant connection was wiggly-jiggly (technical term... don't feel bad if you haven't heard it before).  I actually had to insert a piece of solid copper wire into the crimp tool to create more of an indent into the crimp when using my "lug" crimper.  This wire was only there to help with the crimp and was removed afterwards. 

The bad thing about MC4 connectors is that if you aren't quite happy with something, you can't disassemble it after you've installed the backshell.  My only option with the first "wiggly-jiggly" MC4 connector was to cut it off entirely and replace it with another one. 

MC4 connectors do tend to be a little safer than other connector types, because the metal surfaces are less exposed.  Disconnecting them can be a bit of a hassle... even if you do have a tool, because not all MC4 connectors are alike.  The tool works better for some MC4 manufacturers than others.

Many thanks to DavidM and Merlin for answering incessant questions about batteries and other components.  Without them, this installation would have been a "Three Stooges" episode.  Thanks also to Pinstriper and GrampaKilt who provided insight for how to mount the batteries indoors.  Thanks as well to folks who commented in the forum.  The ACF is great...  Not only did I have an install that was admired by my RV maintenance guy, but it also helped with my marriage.  My wife hates when I babble about these things at the dinner table :-)

I made the mistake of going to an RV show with my wife.  She now wants a window in the front of our Camplite 14DBS!  I thought of this project, and showed her your pictures.  Now she may be thinking of leaving our CL so that she can be in yours.

How has it been going?  Any leaks or "road carnage"?  Does the window have a built in shade or screen?  I'm wondering how well the shade/screen mechanism would work over a curved surface.  My wife would be happy to just have light coming in even if she couldn't open the window, but I have to ask anyway. 

I went to the RV show.  I noticed that the new RVs do not have the type of awning that I have on the Camplite 14DBS.

Most of the awnings were like those made by Solera.  The braces for these are mounted to the wall of the RV.  If I were to install one on the 14DBS, I'd have to mount it someplace where there was a vertical aluminum tube behind the siding of the RV.  I plan to check, but my guess is that I won't be lucky enough to find something like that in the narrow area where I would like to move the awning support.  The cost is a bit prohibitive too... I did a quick search, and a basic manual (non-powered) unit costs more than $1300.  This is for a 10' wide awning.  Ideally, I would want something that is 8', but they do not seem to be available in this size.

I also noticed some smaller awnings such as those that you might see on a class B camper.  I've had a hard time finding a vendor for these online, but I think that they may be made by an Italian company called Fiamma.  However, since I cannot find install kits, they don't really seem to be an option.  They also seem to be bit flimsy, but if folks think otherwise I'd love to hear it.

At this point I am inclined to stick with Merlin's suggestion for propping the awning support out with a wooden board so that I can open the window a few inches.  However, I may ultimately consider purchasing an 8' awning fabric, removing 18" from my fabric roller tube, and moving the front support back 18".  It seems that if I were to replace the fabric, I'd need to disassemble the roller tube anyway.  I have attached links for two youtube videos that talk about this:  https://www.youtube.com/watch?v=vnxDLPDoVCc and https://www.youtube.com/watch?v=XsMlDTfO2_Q. 

Hmm... I never thought of unclipping the support from the bottom.  I just tried to do this myself.  I wasn't able to swing the support to the left or right, but I was able to swing it out a bit... enough to open the window a few inches.  How long is the board that you use as a brace?

My fabric is getting discolored as well.  I'm not able to extend the awning when it is parked in the driveway since it is sandwiched between the house and the fence.  Water collects there and never gets a chance to dry out. 

There is an RV show in our area, I'll probably go there tomorrow to get an idea of what the new awnings look like.  I know that there are new motor-driven awnings that attach to the upper side of the RV.  They look nice, but I wonder how secure they are.

The supports for the awning in our Camplite 14DBS travel trailer block the window on the front right side.  Unless we have the awning extended, we can't open the window! 

I was recently on a short trip when the wind picked up just before nightfall... I closed the awning, which meant that I had to close the window as well. This really cut down on the cross-breeze, because the tiny kitchen window is the only thing left on that side, and it doesn't open all of the way.

I'm wondering if I can "shorten" the fabric roller tube, and move the offending awning support so that it sits just behind the window, and just in front of the wheel well.  At first I was concerned that I'd have to mount the support where a vertical aluminum beam goes up the side of the trailer, but after looking at it, I noticed that the support is mounted with big (#14?) hex-head sheet metal screws at the top and bottom of the trailer.  So instead of drilling new mounting holes into vertical posts, I'd be drilling them into the horizontal beams that run along the top and bottom of the trailer.

Ideally, I'd like to move the front support 18 to 22.5 inches to the back.  The current fabric is 9' wide.  I think that I can buy new fabric that is 7.2' wide.  I think that the roller spring assemblies are only 42" long, so I'd have enough space for both roller spring assemblies even if I removed 22" from the roller tube.  I know that I'd have to move the light fixture.  Here is what I was thinking:
- remove fabric roller tube from trailer (carefully so as to not get injured from uncoiling spring mechanism)
- remove roller spring assembly from one side
- remove around 22" of the roller tube
- move awning support 22" to the back of the trailer (which would put it around one-half inch from the front of the wheel well)
- install narrower awning fabric on roller tube, and reinstall roller spring assembly
- replace fabric roller tube on trailer

Has anyone ever done this and lived to talk about it?  Or are there newer/better options available nowadays?  I just looked for Dometic awning parts, and it seemed like there weren't many available online.

If you do get a LiFeP04 converter, you may want to get a "two-stage" model instead of a single-stage model. When I was considering the PD4045CSV unit mentioned above a few months ago, it only supported single-stage... meaning that it always charged at 14.6V.  Two-stage models will "know" when the charging process is getting to the end, and adjust the voltage to 13.6V, which is better for Lithium batteries. Perhaps PD has updated the PD4045CSV to include two-stage capability?  I know that they were considering this a few months back, but don't know if they actually completed it. On the plus side, I believe the PD4045CSV had a jumper that allowed one to "switch" between lead-acid an lithium batteries.

Since I was no longer using my lead-acid battery, I went with the PD "deck mount" PD9145ALV.  It only supports Lithium, but is a two-stage charger.

I suppose that running at 24V could have been an option.  Presumably, when running at twice the voltage you would have half the current, and therefore half the voltage drop.  I could have put my two batteries in series to get 24V (Battleborn supports series configurations up to 48V).  I'm pretty sure that the Victron solar controller supports this.  However, the Progressive Dynamics AC/DC converter and the Victron DC/DC converter that I have do not support 24V.  Anyways, the biggest problem is with the connection to the TV's alternator... so I'd need some kind of converter near the alternator. 

I'm comfortable making changes to the trailer, but making changes to the truck is another matter.  I'll probably end up making some kind of change, but I'll need to do some research first.  I'll probably be bugging you folks with questions, but it may not be until next year.  Thanks for the thought though.

Thanks!  After looking at the picture, I noticed that the cable to the circuit breaker is hanging down a bit.  I pulled this down so that I could put the clamp ammeter around it.  It's a handy spot for measuring current, but I need to stuff it back and/or attach another cable clamp to keep it in place. 

Regarding the "one long solar cable" vs "multiple short solar cables"... I've found out that the contact resistance of an MC4 connection and a Anderson SB50 connection are both comparable to about half a foot of cable (plus or minus... the Anderson is actually a bit better than the MC4).  So I'm thinking that it may make sense to buy multiple short cables and attach them as needed, and have the flexibility to put them in parallel if my solar panels are in parallel.

Merlin, thanks.  If folks are using 4AWG wire, then it's understandable why I am having problems using 10AWG!  I think that you are right... I'll end up upgrading to a beefier cable and connector, but probably not any time soon.  Until then, I'll probably use the voltage limits while driving (and expect low charging rates), and in a pinch disable the voltage limits if parked at a campsite.

David, I only have one more thing to do, and that is to finish the cable for the solar panels.  However, the installation in the trailer is essentially finished.  I've attached pictures of the Victron equipment.  Pictures for the racks used to hold the AC/DC converter and the batteries are in this thread.  Like an idiot, I failed to take a picture of the AC/DC converter after I installed it in the tray and then put everything back together... but I can get one if you like.

Here is a picture of the Victron components, as seen from the inside of the cabinet where we keep dog kibble.  The wiring is routed from the other side, where the deck-mounted AC/DC charger and DC distribution box is installed. 


As you may notice, the positive bus bar is exposed, so I made covers out of sheet PVC.  They are held in place by "knobs" that I tapped so that they could be screwed on. I also covered the aluminum tubing near the positive bus bar with Gorilla tape (to act a bit as an insulator).  This may not be the best thing, but its better than nothing!
.

This is what the equipment looks like from outside the cabinet. 



For the solar cable, I'm currently looking for 8AWG "jumper cord" to connect to the MC4 connectors on the solar panels, but I've not been able to find it.  So I'll probably settle for two separate 8AWG positive and negative cables like these.  I'll probably make a short 8AWG "Y" cable to allow me to connect the MC4 cables into the Anderson connector on the trailer. 

I'm debating whether it is better to have one pair of long cables (say 40' one-way), or multiple pairs of short cables (for example, three 20' cables).  Having multiple pairs would allow me to configure the cables in series or parallel.  This would give me the following configurations, assuming that the MC4 connectors had no loss (probably not a good assumption).  All of these cable configurations assume that the solar panels are configured in parallel.  The cable losses are determined using David's WireSizer program.
-    Three parallel 20' cables (one for each solar panel).  5.3A per cable, 20' one-way.  1.2% percent loss.
-    One 20' cable (for all three solar panels configured in parallel).  16A total, 20' one-way.  3.5% loss.
-    Two 20' cables (for all three solar panels configured in parallel).  16A total, 40' one-way.  7.0% loss.
-    Three 20' cables (for all three solar panels configured in parallel).  16A total.  60' one-way.  10.5% loss.

I'm assuming that any drop in voltage on the input side will ultimately translate to the same drop in current on the output side, given that the output voltage remains the same (either 14.4V or 13.6V).  And if the parallel solar panel configuration resulted in too great a loss, I could play around with the solar panels in serial.

In response to David's earlier question about alternator voltage... Yes, the alternator voltage was 12.6V when I did my last test with the low voltage lockouts disabled.  It's possible that the part of the 3V drop is because the DC/DC charger is drawing extra current to compensate for the lower voltage of 12.6V... and that extra current means even more voltage drop!  My math suggests that in an ideal case with #10AWG, the current draw should have been 25.6A (instead of 29.7A), and the voltage at the DC/DC charger should have been 10.8V (instead of 9.6V).  It's like I'm seeing one and a half times the resistance that I expected to be seeing.  Even though the 7-way connector is new, it probably is adding some extra resistance, as well as the hitch's junction box, and other connectors. 

During my previous tests, I tried to "fool" the alternator into operating at a higher voltage by discharging the TV battery before running the tests.  However, that didn't seem to work.  Perhaps I didn't discharge it enough, but I'd be a bit leery about discharging my TV battery a lot in order to charge my trailer battery.  This might be good for a test, but I wouldn't want to do it regularly. 

In a pinch, I would like to think that CharlieM's solution might be workable in a campground setting, where I can monitor things via Bluetooth on my cellphone, and had extra fuses.  With the current wiring and connectors, I'd have to expect a current draw of nearly 30A, if the alternator voltage was 12.6V.  If there is another way to get the voltage above 12.6V without draining the TV battery, that might be even better.

I agree that it's tough to get lithium batteries to charge with an alternator voltage of 12.6V.  In retrospect, it would have been good to have a DC/DC charger that would allow one to control the output current, so that one wouldn't have the larger voltage drops.  Without this, the only option (it seems at the moment) is to put in heavier gauge lines and better connectors.  I may wait awhile to do this.  Until then, I'll be glad to get 6A (IF I can get it) and carry extra fuses.  In a pinch, I would hope that I could disable the low voltage lockouts as CharlieM suggests.  Is there a risk of harming the alternator if I do this, particularly if the engine was idling at a campsite?

Last night I had left the refrigerator on in AC mode with four quarts of ice to to help bring down the temperature. This morning I ran the refrigerator on DC mode.  It consumed around 15A, but the new relay worked and I was confident that I could use my refrigerator in DC mode... even if it were to consume a lot of current.  Since it was hot, I also had the fans on... this added another 5A of current.  So the refrigerator and fans were consuming around 20A.  It took around 5 hours to get the lithium batteries to 100AH.  By early afternoon I was ready to start the test!

I turned on the ignition in the truck, and monitored the voltages and current.  The voltage into the Dc/DC charger was around 13.1V, and the output voltage was around 13.2V.  The output current varied a lot, but seemed to be around 6A.  This confirmed what I saw during my recent trip.  Even though the maximum current was 18A, the charger would turn itself off because once the current became too high, it would cause the voltage to drop below 13.1V (the default threshold for engine shutdown detection).  I thought that this cycle might occur every two or three minutes... but it was actually happening much faster than that.

Rather than wait to collect more data (like an adult would), I decided to stop the test and lower the threshold to a lower value to see if this would let me get more than 6A!  I got nothing.  By that time, the alternator decided to sit at 12.6V.  I turned on tow mode, high beams, and sat there with my foot on the gas pedal, but the alternator still sat at 12.6V.  At that voltage, the DC/DC converter declared that "engine shutdown" was detected, and kept the charger at a disabled state.  It seemed that the alternator reduced the output voltage to keep from overcharging the TV battery.

So...  I did my best to run down the truck battery.  With the 7-way connector connected and the engine off, I turned on my high beams, running lights, and even recharged my iphone from the cigarette lighter. 

After 45 minutes or so, I reran the test.  As soon as the truck started up, the TV voltage would be around 14V.  The DC/DC charger would produce around 10A at 13.3V.  A couple of minutes later, the TV voltage would drop to 13.1 volts,, and the DC/DC charger produced around 6A... but this would decrease to around 4A a minute later.  A minute after that, and the TV voltage would drop to 12.6V, which would ultimately turn the DC/DC charger off due to "engine shutdown detected".  I am now wondering how I got an average of 6A of recharging on my recent trip.

For grins, I disabled the "engine shutdown" and "low voltage" thresholds.  The DC/DC charger drew 29.7A.  The input voltage was 9.6V.  It provided 17.9A at 13.5V.  It didn't blow my fuse, but came pretty close!

Actually, I was glad to get that much.  I really do think that the DC/DC charger is turning on and off, and your test would be a good way to confirm this.

In the past, I wasn't really able to rely on DC charging at all.  During one of the first trips out with the Camplite, I made the mistake of leaving the refrigerator on DC while we drove.  When we arrived at out destination, the house battery had gone down from 93AH down to 25AH!  The refrigerator had been consuming the battery power, and the tow vehicle was doing little (if anything) to replace it.  Since we were at a non-electric site, I had to use the tow-vehicle to recharge the battery without the refrigerator running.  Even that seemed spotty... probably because the truck alternator was switching between 14V and 12.6V.  I've read that the alternator will reduce voltage if it thinks that it may be overcharging the truck battery, but I'm not sure where the "logic" is to implement this.  I tried little tricks to keep the alternator running at 14V (turning on tow mode and turning on the high beams), but I'm not sure if this made a difference.

I read your post yesterday, and have since disconnected shore power.  Once the batteries get depleted halfway, I'll try the test that you suggest.  This may be a good time to try out the refrigerator on DC power, now that I've replaced the broken relay that kept it from working in the past.  That will be sure to consume a good amount of power from the batteries.  I've been reluctant to "waste" the energy, but this might kill two birds with one stone.

Last Thursday I finished installing the Anderson connector on the underside of the trailer, so that I could easily plug in a long cable to the solar panels.  I was eager to get the Anderson connector installed, because that meant that I could finish all of the work on the trailer for the Lithium battery upgrade.  All of the connections inside the trailer for the Victron equipment were now complete, and I could put everything under my kitchen counter back together... including the cables that came from underneath the trailer into the AC/DC conversion area underneath the cooking range.

I managed to do this just in time so that I could take the trailer to a family reunion in the Alleghenies in PA.  The surroundings weren't too exciting... I was parked in an in-law's driveway... but it gave me a chance to check out the DC-DC converter and exercise the battery capacity.  Although we didn't spend much time in the camper, our aging dogs did, and we made sure that every fan was available to be put to use if it got too warm.  We refrained from connecting to 120V, and used the lithium batteries for normal functions as well as popping out the slide-outs, water pump for showers, and recharging our iPhones.

Since the batteries were fully charged before we left on the trip, I did not expect any charging to occur via the DC/DC charger.  However, I was hoping to connect to the DC/DC charger while we were on the road.  Unfortunately, I was not able to use Bluetooth to connect to the Victron DC/DC charger... I don't think that the signal could make its way out of the steel cab on the Silverado and into the aluminum trailer.  Therefore, I couldn't tell what was really going on with the DC/DC charger.  During the 43 hour period that we were parked, we consumed around 70AH.  This is around 1.6A per hour.  When we got back home after a 5 hour trip (including a .5 hour break to eat lunch), the available capacity had increased by 27AH.  This means that the DC/DC charger charged the batteries 6A per hour on average.  The nominal output of the charger is 18A per hour, but I suspect that there were times that the charger turned itself off due to under-voltages.  While the charger was actually charging, the current was probably much greater than 6A, but if it got too high then the voltage drop from the cabling might have been enough to turn the charger off.  I really wish that I could have connected via Bluetooth so that I could have seen what was going on.  At least I didn't blow the 30A fuse! 

For the solar connection to the trailer, I used Anderson connectors because they are easier to attach/detach that MC4 connectors, and should be able to carry more current than MC4 or SAE connectors (which seem to be available with thinner wire gauges, but not thicker ones).  The ones that I purchased can carry up to 50A.  I mounted the connector on the underside of the trailer using a Trailer Vision mount.  It has a spring-loaded cap that hopefully will keep some of the road crud from splashing onto the connectors.  I tried to put it someplace that would be easy to reach from the side of the trailer, but not someplace that would get excessive spray from the tow vehicle or the wheels of the trailer.  I've attached a picture.   I used 8AWG wire with protective loom, which was fed through the same opening on the underside of the trailer that was used for shore power and the 12V from the 7-way connector.  Since the Victron solar controller was in the same area, cable lengths were pretty short.

I still have MC4 breakout connectors and an MC4 fuse just before the solar panels.  I still need to make a cable that would have an Anderson connector on one end and MC4 connectors on one end, to connect to the solar panels.  Ideally, this would be a 30-40 foot UV resistant zip-cord cable at least 8AWG thick.  BatteryCablesUSA advertises 6AWG (no 8AWG), but it is currently out of stock and may not be UV resistant.  If anyone has any recommendations that aren't copper clad aluminum (CCA), I'd love to hear it.  A lot of stuff on Amazon is only 10AWG and/or CCA.