A few little electrical projects..... without zapping myself =)

Three of the "modifications" I wanted to do to my new little Barefoot Eggy right off the bat were (1) install my brand-new Battleborn 100Ah that I had purchased for my T@g, because I had no intention of letting that go to the T@g's new future owners!!  (2) get the Battelborn lithium hooked up to solar panels, since the Barefoot has a solar port, and (3) install a Smart Shunt battery monitor, because I'm anal retentive.  LOL.  Joking, not joking...  as a former recovering scientist, I love data and the little plug-in doohicky does not provide enough for decision making purposes.  Specifically, real-time amp draw, which allows one to estimate how much "time" you have left on the battery until recharge - a parameter that I personally find useful!

Because one of the most interesting problems in these little rigs is how to make sure you have enough power to last X amount of time, without plugging in to "shore power."  That's often referred to as "dry camping" or "boondocking." Since I have a loooong history of camping away from traditional campgrounds or electrical outlets, this is the most natural style of camping for me to pursue.  Sure, it's nice to plug in - I mean, holy luxury!!  But if I want to go out west and find some National Forest or BLM land in the middle of NOWHERE and still be self-sufficient, I need to know that my heat source will not go out in the middle of a cold night because I drained my battery.  (Not that I've done that.  Ever.) Also it's super-nice to be able to camp in the non-electric sites, away from the big rigs.  Having off-grid power gives a lot of flexibility in terms of site selection, for sure!

The T@g originally came with a "marine" lead-acid battery, and I had never used one of those- was a bit surprised to learn that although it *says 100Ah, you can't actually **use** more than 50% of that without damaging the battery? Seems a bit mislabeled to me, then! Ugh.  So I started learning about lithium and how it gets around that problem.  (OH, also lithium requires no maintenance, and can stay in the trailer, even in winter, without a trickle charger...  and hey, I like easy.). In sum, I surmised that although it's more of an investment, lithium would allow for longer "dry camping" with less worry - so when I killed the OEM marine battery from the T@g (oops), I opted for lithium! Of the most salient brands, I was considering Renogy and Battleborn since those were the two the majority of the folks on the Nucamp Owner's Group on Facebook recommend.  Plenty of cheaper ones out there, but you often get what you pay for, and, um lithium can explode?  Also, going with a well-known company allows for the opportunity for technical support.  In the end, the folks at Battleborn were SUPER helpful setting up the lithium in the T@g - guided me through all of the parameters I needed to change on the Victron MPPT, and on the Victron battery monitor (BMV) I had installed on the T@g.  I may consider Renogy more next time, since their bluetooth battery monitor is integrated therefore without a need to purchase and install a shunt.  

The charge controller in the Barefoot is able to "auto-detect" lithium versus lead-acid, and switch to optimized charge parameters according to whatever battery it sees - so I knew that for that first step, transferring the Battleborn to the Barefoot should be straightforward.  (I think I covered that in a previous blog?) So that left hooking the Battleborn up to a solar panel, and adding a battery monitor, even though some folks on the Nucamp Owner's Group were of the opinion that the plug-in was perfectly sufficient (more on that later).  

I should note that I had an ace card up my sleeve for this project:  my dad, now 81, was an electrical engineer and his specialty was actually power conversion, with a ton of product knowledge in both lithium and solar.  (This stuff is not intuitive to me, personally.  FFS, I am a PhD biochemist turned chiropractor, not an engineer...)  I'm so glad to have resources to turn to!!  You know, supervisory influences that help me to know blow things up or zap myself.  Tee hee.

The kind folks at Nucamp confirmed that just hooking my Jackery 100W panels (from my Explorer 1000 station/package that I snagged on Black Friday last year, which conveniently serves as backup power for the Barefoot and as an inverter) directly into the solar plug (my original thought) would be a, haha, *bad idea* (I learn new stuff all the time!  Good thing I ask questions, I seriously would have just plugged it in and assumed it would work fine....) and also confirmed that a Victron MPPT 75/15 was sufficient for my purposes, max two 100W panels.  The next question was, do I splice that in to the wires going into the controller *inside the cabin, or *outside the cabin?  I opted to not alter the Barefoot's tangle of wires under the dinette bench because i was absolutely just too intimidated by the prospect of finding the right wires.  I mean.... it's out of sight for a reason lol!   

Instead, I chose to splice into the DC 8mm female to SAE connector wire that I found to connect from the Jackery panels into the solar panel in the side of the Nautilus box (above), but I had to solve a little problem first:  Polarity, because apparently it matters...  Which adapter end (above) should I use to get the current from the solar to the lithium?  So I dug around in the Nest-O-Wires under the dinette bench and found the black and red coming from the Nautilus box...  Red wire on top! and was able to use the product as pictured above, no adapter.  

Speaking of polarity, when you plug the red and black wires into the Victron MPPT, look carefully for the + and - sides.  I had all the wires cut, trimmed, and into the module and handed it to my dad for double-checking and he chuckled and said..... try again! Haha.  Again with good thing I have supervision.  Because if you wire it backwards, it won't work =) That said, Victron states that if it is wired incorrectly, the MPPT will heat up but will not send backwards juice to the lithium, which is a good failsafe!

And here's the final setup.  I will plug this in only when I want to juice the batteries with solar, otherwise the panels fit so nicely into the storage area by the Barefoot's door.  Did I mention that the Barefoot has really well-designed sneaky storage areas?  Here's the MPPT plugged into the solar port inside the Nautilus box:

And... drumroll... Functionality confirmed via Victron bluetooth app!!! Had to set the parameters for lithium, which I had done for the T@g so I already had them in an old email.  See, THIS is why you should save old emails....

So now I have the ability to recharge my lithium on-the-fly, via solar input!  Very glad Nucamp included a solar port on this little rig.  I recognize that due to the shape of the hull, solar panels on the rig itself would have been a very challenging engineering problem - and frankly, in the past I have had a bit of frustration positioning the T@g such that the solar panels were in an optimal position for recharging, given that the sun sort of moves though the sky?  Now I can easily reposition my solar panel(s) for maximum efficiency!

The SmartShunt installation was a bit trickier.  See, here's the thing:  the custom-made battery box that Nucamp designed for the Barefoot, quietly tucked under the right side of the dinette (shown without cover, that screws on the front,

is very nice looking for sure and I love the tie-down strap and the slide-out shelf, but it's a bit of a challenge to add the battery shunt because as you can see you can't add it inside the box (no room), you can't add it on top (no clearance, the bench pull-out slides across of the top of the battery box) and you can't stick it on either side because you really can't access those spots.  And in any case, you'll have to drill a hole in the box to get the wires thru.  So I opted to drill a hole in the front cover (haha extra ventilation, I guess): 

to pull the wires through.  Since I had wired a Victron BMV before for the T@g, I actually had an extra jumper cable appropriate for the task at hand, albeit the "wrong color" (hahaha), so I literally wrote "BLACK" on the red cable to remind my future self that yes, I had done this on purpose.

Here's the outside, all wired up and battery box re-sealed -  so yeah, there's a "bend" in the cable but it's not sharply crimped so I say fair game.  I will just have to remember to never put anything conductive in that storage area next to the battery box.  Fortunately this is where I store the 2" memory foam topper which is NON-conductive! 

and, for the finale, after inputting the parameters for the lithium into the Victron app......

Back to the "anal retentive" comment.  I don't understand why these two are not showing the same battery voltage.  Going to email Battleborn about that to make sure I have all of my parameters correct.  That said, as a control for my experiment, I confirmed the battery voltage with both the multimeter and the plug-in, and they all give the same reading.  So YES, the plug-in will allow you to check battery voltage with pretty good accuracy!  FYI a multi-meter will not work well for monitoring a battery in a Barefoot due to the position/location of the battery, unless you want to open the storage compartment and un-screw the face off the battery box every time you want to check the battery.  What the smartshunt gives you that the plug-in does not, is amp draw and a simple calculation of "hours left." Unfortunately I did not take a screenshot of that in the app, so I will post it later on.

VERY happy with this seemingly small project (which was a big deal to me!!) A few suggestions for Nucamp to consider:  Having the rig "solar-ready" with an MPPT integrated would be a nice upgrade for future models, and salespeople/dealers should be trained to be clear that the solar port needs an MPPT to safely input from a panel to the battery.  (I was not told that.) And while the battery box is lovely (very nicely made!  Vented on the back and bottom, too!) a pre-cut opening on the front would be nice, both for handling the front of the battery box while taking it off/ putting it back on, and for egress of wires for a battery shunt (or additional batteries? That's an interesting question unto itself, it looks like there's room for a few more Batteborns as a battery bank in that storage compartment....) 

So with these upgrades, and my Jackery 1000, I am now ready to dry camp / boondock WITH the two-way fridge for maybe a week?  To be continued, once I gather some more data =)