Storing Some Juice, II

Our original plan had been to replace the original 12 volt batteries with a pair of Interstate GC2 6 volt golf cart batteries that were easily available from our local Costco, but BJ and I were wandering the Mesa Market Place one day and ran across a couple outfits with excellent prices on Trojan batteries. I turned Jeff loose to do some research. 

He talked with both vendors and ended up getting four US Battery 232 amp hour batteries for $110 each (plus tax.) These were fresh batteries - the construction date stamped on their posts was October 2017. With that sort of pricing, it was an easy decision to upgrade from the 205 amp/hr batteries at Costco.

The original battery tie-down bolts were 9 1/2 inch long carriage bolts. With the new, taller batteries, we needed 11 inch bolts, but my favorite hardware store only stocked them to 10 inch long, so we used Nyloc self locking nuts and fender washer on 12" long piece of all thread. On the top, we were able to reuse the tie plates and nuts. With two batteries in place we were already up about 50% on available amp hours.

The base for the battery box drawer was attached with four bolts through the bottom of the storage bay, retained by fender washers and nyloc nuts on the bottom.

Battery boxes for a pair of GC2 sized batteries are not terribly common. We got this one from All Battery Sales & Service in Everett, Washington because I'd been so happy with the one I've used on our Scamp for the past six years.

I wanted to vent the box overboard so I added a PVC conduit body to the cover, attaching the body with two screws and sealing it with trusty 3M5200.

I'd hoped to be able to vent directly out, but the battery box height was such that the vent would hit the aluminum angle that forms part of the storage bay. I drilled a 2" hole through the back of the bay as well as 7/8" holes for the battery cables.

A couple of elbows and some 1 1/2" PVC pipe created the offset solution for the vent.

The vent pipe slides over the sleeve on the conduit body. The other hole in the conduit body is unnecessary and closed with a plug.

The battery box is retained in the drawer in case the driver wants to try some aerobatics. I elected to us a 4' loop strap from NRS.

The NRS loop strap is built for use on white water rafts, but the cam buckle works excellent and I've had a long history of success with these, so it became my logical choice for a simple tie-down system.

We used 1/0 battery cables from Windy Nation on Amazon for the 18" ones that we needed with the batteries in the original location. Unfortunately, they apparently don't do custom lengths, nor 6' long lengths. I didn't want to deal with the extra length or the wait, so we had cables custom built by a local auto stereo shop for the connections to the batteries in the drawer. They are retained by Adel clamps screwed to some aluminum angle that is riveted in place.

For this system, we're now very battery heavy. The batteries could easily support two or three more panels, but it gives Jeff the capacity to enjoy a week of rainy, overcast fishing without needing to fire up the noise maker.

Storing some Juice

The Vista came stock with a pair of NAPA 12 volt, 75 amp hour rated batteries for the coach circuits. Jeff knew he wanted more power, so we started researching 6 volt golf cart battery options. The plan is to put two in place of the original coach batteries under the stairs and to put the other pair in the bay adjacent to the stairs, alongside the solar controller.

The biggest challenge was making the second pair easily accessible for servicing. We ordered a pair of 250 pound capacity, full extension drawer slides and a battery box for the second pair and then I got busy cutting up some wood.

The plan was to build both the base and the drawer from Baltic birch. I did some dry fitting and drilled for screws to hold the major pieces. 

With the dry fitting completed, I epoxied the seams and screwed the pieces together, expoxied the base, radiused the edges and glassed the structure inside and out. With the weight of the batteries and notorious Alaska roads, we wanted to be sure the base structure would not shift or loosen.

The base was painted and the drawer slides were installed

so that I could start dry fitting the parts for the drawer portion. Amazingly, the vast majority of my initial cuts were correct, with just a couple needing a little additional clearance.

Like the base, the structure was epoxied together

and then glassed inside and out.

Amazingly, everything fit without any shims.

The biggest challenge was the installation of barrel nuts in both sides of the base so that a machine screw could be run through the face of the drawer on both sides. These screws keep the drawer firmly closed in transit. The two screws will be removed when opening the drawer to service the batteries.

Lost Dutchman Testing

It was a first for us. We've enjoyed our Scamp for over seven years, but we'd never stayed at Lost Dutchman State Park. BJ spent many hours in the park and surrounding area as a member of the Search & Rescue group, but we'd never camped there. Too close and usually too full.

Since Jeff is leaving his new rig in Arizona for the winter, they came down for a long weekend and we managed to reserve a couple sites right across the road from one another.

We both had to suffer with this view. In our case our large back window framed the mountain while in Jeff's case the front window provided the best seats in the house.

We did work on a couple mods for his rig, but I also got a chance to go geocaching with our grandson for a while one morning until the heat got to be too much.

Always nice to be young - makes the tree climbing easier!

I even loaded up some charcoal and brought a dutch oven for one of our dinners.

Pot roast - the easiest thing to fix - was excellent. Our daughter and son-in-law came out so we managed to have everyone together in one place. The pot was empty when we got finished!

We enjoyed great weather, excellent time together, and beautiful sunsets. No wonder valley visitors rave about Lost Dutchman State Park!

Vista Solar, Part 3

With the controller and the portable panel components in place, it was time to install the roof-mounted panel. We'd already determined that our feed cable would pass down the wall the creates the inboard side of the bathroom and serves as a wire chase for all the annunciators, slide controls, etc. The vent pipe is in the forward end of that wall.

A 3/4 inch Forster bit made quick work of drilling through the fiberglass roof without getting crazy with the 3 inches of foam below the roof.

A matching hole was drilled in the center of a 4x4 plastic junction box and then that box was attached with the fiberglass roof with 3M Very High Bond tape, followed by a bead of 3M5200 marine adhesive sealant around the outer edge.

The mounts that we got from AM Solar came with 3M VHB tape pre-installed on the feet. I marked where they were going to go and wiped down the fiberglass roof with alcohol to insure a clean surface before sticking one pair and then the other to the roof. Like contact cement, you only get one chance! A bead of 3M5200 sealant around the edges of the feet completed the installation.

With the feet in place, the cable was run through conduit from the junction box to the panel and then connected to the panel with the same style waterproof heat-shrink connectors that I used on the portable panel. Both panels have an in-line fuse installed at the panel end of the wiring.

I used flex conduit to provide UV protection to the solar cabling. The conduit is attached to the fiberglass roof with 3M5200.

There's lots of real estate left if additional panels are desired.

I left extra cable in the junction box. If extra panels are added, the junction box can serve as a combiner box.

Inside the bathroom at the ceiling is a triangular box. I'd hoped I wouldn't have to open it, but I couldn't get the solar wiring to feed more than 18 inches down the wall so I popped the four staples that held the wall covering in place to make it easier to feed the wires.

The vent pipe that I pointed out on the roof is at the right side of the wall opening. The solar cables go through a pre-existing hole in the floor, across the top of the grey tank*,

over to the corner of the sink cabinet,

and then down through a hole I drilled in the tunnel cover just ahead of the grey tank,

leaving a short run to the terminal blocks.

* The grey tank has inlets from the shower, the bathroom sink, and the kitchen sink. When we went to pull the wires from the electrical chase to the kitchen cabinet, we discovered the top of the grey tank was wet. Turns out one drain had a hose clamp, one had a hose clamp that had never been tightened, and the kitchen sink one didn't have a hose clamp AND WASN'T EVEN ALIGNED with the tank port. Quality Assurance anyone???

With both panels wired, but being too lazy to go back up on the roof and tilt the roof panel, it was time to install the Bluetooth adapter to the controller and see what we had for results.

This was about 9 a.m. with neither panel oriented optimally. Can't complain! I wasn't sure that the Bluetooth dongle was going to be worthwhile, but once I've played with it a bit, I'm convinced it's required equipment.

The solar install has been fun. Time to do some more mods one of these days soon.

Vista Solar, Part 2

I got the wiring done for the controller and the portable panel before taking time off for a river trip. The buss bars on the left are where the panel feeds come in and feed to the controller. The controller feeds to the coach batteries at the lower left, while the feed from the portable panel comes through at the lower right corner.

The mating Anderson connector, with a red weather guard is mounted to the bottom of the side wall, just behind the entry steps.

Storing rooftop panels is easier once you get the work done. For now we'll have one up here but with plenty of room to add a couple more if they decide it's necessary.

The roof panel feeds will enter the controller compartment through a couple grommeted holes just above the yellow arrow in the first picture.

The portable panel will be stored in the rear compartment. Thankfully, the plywood deck for the bed provides plenty of structure. I added a pair of carriage bolts in two places and put the mattress back in place.

I fabbed up a plywood receiver on the street side end that is screwed and glued to the plywood. The receiver is designed so that one end of the portable panel goes there, and then the other end is lifted up and retained by a 2" nylon strap with a Fastex buckle. The panel is kept on the street-side 'shelf' by a similarly constructed stop that is also screwed and glued to the plywood ceiling.

Closed cell foam bumpers will be added to the back of the panel frame to restrict vertical bouncing. The face of the panel is protected from any extraneous damage by a thin plywood panel retained by a couple smaller straps.

Once our river trip is over we'll see about getting the roof panel in place and running the cabling for that panel and the battery monitor.

Vista Solar, Part 1

With a couple years experience using solar in his travel trailer, I didn't have to spend any time discussing the issues related to installing a larger, true sine wave inverter to power the microwave since I knew it wasn't considered essential. Instead, I concentrated on those items that would be used while boondocking.

I was pleased to see that the inverter idle draw was only 10 watts. None the less, the inverter is not likely to be powered except when using one of the TVs.

The big draw will be the large TV which won't be used that much. It's quite likely that 200 watts of panels will be more than enough for their typical use patterns. We selected the same Renogy 100 watt monocrystalline panel that we used on his trailer because of its compact size and high Vmp. One will be configured for portable placement and the other will be roof mounted with tilting capabilities.

I brainstormed a shopping list and shortly thereafter, stuff magically started showing up at my door. Like the other systems I've put together, this one will use 8 AWG cable to reduce the line losses.

I did some of the stuff at home where tools were easily available. Some aluminum angle was used to create legs for the portable panel.

The secret to the legs is the plastic washer and self locking nut. With the plastic washer between the leg and the frame, the self locking nut can be tightened down enough to put some friction on the hinge angle.

The installation is using two different 8 AWG wire styles. The feed wire from the portable panel is 'zip cord' from PowerWerx. The red/black paired cable uses finer wire for more flexibility, which makes it much easier to use with the portable panel. The roof-mounted panel/s will use MC4 Solar cable. It has fewer strands of thicker wire resulting in a stiffer wire, but it also has a UV resistant cover.

The extension cable for the portable panel was permanently connected to the panel leads with waterproof, heat sink butt connectors. They're waterproof and serve as a strain relief across the connection.

The other end of the portable panel cable got an Anderson SB50 Power Pole connector. These connectors have beefy contacts and result in a connector that cannot be inserted with reverse polarity. We used these on Jeff's trailer project a couple years ago and it has served well.

Unlike last time, this time I spec'd the extra Tee handle to make it a bit easier to connect and disconnect the pair of Anderson connectors.

The rood top panel gets fitted with AM Solar's mounting system. This system is fabricated from stainless steel, and allows the panel to tilt in two directions. It's a quick and easy installation on the panel.

Each corner gets a bracket that is retained by one bolt with self-locking nut.

The mounting foot connects to the adapter with a threaded knob. The foot will be attached to the fiberglass roof with 3M Very High Bond tape and then sealed around the edges with 3M 5200 Marine Adhesive.

The Victron controller* and all the system connections have a home in the forward curb-side bay, as close as I could get to the coach batteries.

*We considered the TriMetric TM2030 / SC2030 combination, but the Victron combo got the nod because of the cleaner looking monitor. The MPPT controller is a bit of overkill, but will work nicely with the high Vmp of the Renogy panels.