Solar at Spring Branch RV Park

Spring Branch, Tx

Back in early August, I made arrangements to have solar power professionally installed on our RV the week of December 10th at Spring Branch RV Park in Spring Branch, TX.  We arrived here on Sunday the 9th and our installer, Bill Murray, stopped by a couple hours later to look things over and formulate a game plan.  At this time he left the six 180 watt panels and the two 300 amp hour batteries at our location.  The installation would begin the next morning at 8:30 am.

The first order of business was to determine the placement of the panels on the roof and how to run the 2 gauge welding cable from the roof to the basement, where the charge controller and batteries would live.  Our rig was “solar ready”, which amounted to a 10 gauge wire being brought from the battery compartment to the roof.  According to Bill, that wire is barely sufficient for a single panel.  So much for solar prep.  The challenge is to minimize loss when getting the power from the roof to the charge controller and RV Solar Solutions, the company Bill works for, tries to keep that loss below 2% so they go with the flexible 2 gauge welding cable.  When placing the panels on the roof, the position of each panel was selected to minimize the potential for shadowing from other things on the roof like air conditioners and antenna.

Bill determined that the best place to bring the wire into the basement was through the coat closet and down behind the wall of the instrument panel closet.  This would bring the wire along the same path as the primary power lines coming from the basement to the breaker boxes housed in the instrument closet.  The small battery monitoring unit would need to be mounted in the instrument closet as well.  This monitor, the Victron BMV-712, can display all the necessary information but you need to page through each screen using the +/- buttons on the unit.  Luckily, the unit will relay all the information via Bluetooth to an app on your phone or tablet.  This gives you all the information about the batteries,  including state of charge and voltage as well as how much power is going into the batteries (charging) or coming out of the batteries.  A lot of this information is also available on the existing magnum battery monitoring display that came with the RV.  By the end of the first day, all the panels were mounted on the roof and the second day 2 was spent wiring the panels to the junction box and feeding the primary 2 gauge cable from the roof to the basement.

On the third day, the original lead acid batteries that came with the RV were removed and the 2 drop-in lithium ion batteries (LifeBlue model LB12300-HC) were put in place.  Unfortunately, the new batteries are too big to fit into the tight compartments in which the 4 original house batteries were stored.  Bill and Dan agreed that the space in the basement right next to the magnum inverter/charge controller was an ideal location to minimize wire runs. This allowed the solar charge controller (Victron SmartSolar MPPT 150/100) to be mounted on the wall nearby and everything related to the batteries to be in the same place.  This area of the basement is insulated and would receive residual heat from the furnace when it runs so there should be no issue with batteries getting too cold to operate properly.  Everything was wired and operational by mid-afternoon on Wednesday.  The batteries were secured in place and the day ended with just some minor cleanup to be done on Thursday morning.  

Wednesday night, we disconnected from shore power and spent the night on strictly the batteries to see how much we used and then see how much the sun gave back on Thursday.  We used about a third of our battery capacity overnight.  This includes powering our residential fridge all night and 4+ hours of television (we had to finish binging Daredevil!).  We also made coffee in the morning before the sun started producing energy.  You’d be surprised at how much energy a Keurig uses to heat the water for coffee!  During the day Thursday, the sun brought us from  a low state of charge (SOC) of 68% to an SOC of  85%.  During the day, the solar panels are providing energy to charge the batteries even as the batteries continue to provide power to the RV.  If more energy is going in than coming out, then the batteries are charging.  According to the information provided by the charge controller, we generated 2.17kWh of energy and reached a peak wattage of 541W.  Like the battery monitor, the charge controller can talk to an app via bluetooth and allow you to monitor realtime information and review the past 30 days worth of information.  We are very close to the winter solstice and should see significant improvement on power generation as the days get longer and the sun gets higher.  The goal would be to get back to 100% SOC before the sun sets.  We look forward to trying this in the near future.

Bill returned Thursday morning to finish up and we spent the remainder of the day washing the truck and the RV.  This was the first washing of the RV and it was way overdue.  It was filthy and looks much better now.  We finished the day with a  visit to a local micro brewery called Rough Diamond.  They are located just 8 miles north of the RV park so it made for nice pre-diner outing.  When we returned to the RV, we decided to turn the shore power back on so we could run the heat pumps and stay warmer as the temperatures were to drop.  If we were truly boondocking, we would have gone with the furnace but why use up propane when we really didn’t have to.

On Friday, we drove the 35 miles down to San Antonio to visit the Alamo and check out the famous river walk. We were surprised to see that the Alamo is in the downtown area.  There were several models of the site from the early 1700s to the mid 1800s and it was fascinating to see how it changed from a simple mission site to a military fortress.  We wandered through the old church and the grounds, observing a musket firing demonstration at the living history encampment.  Then, we took the short walk from the Alamo to the river walk,  entering near the shops and restaurants so we could stop for lunch at a Mexican restaurant. Most of the river walk itself is less commercial and quite lovely with tile mosaics, archways, fountains, flowers,  statues, and benches. 

On Saturday, we drove to Guadalupe River State Park to do some hiking. It was a beautiful sunny day and it was nice to get out and about after spending most of the week in the RV park during the solar installation.  The park has a bird blind facing natural looking bird bath and some bird feeders.  Dan got some  nice pictures with his birding lens and Amy practiced her photography as we hiked the trails.