We tend to do this to ourselves, make last minute decisions and then work frantically to make it happen. The “add solar” decision was one that has been on the table for over a year, but only now acted on. We dug out the records of last years cross country trip and looked at propane usage. We tend to boon-dock a lot and have found that our propane generator set is not the most efficient thing on the face of the earth. We figured that we run the generator between 2 and 4 hours a day when we only drive 250 miles a day. If we drive further then the generator usage goes down as there is more engine/alternator time to recharge the bank of house batteries. 2 hours use is 1 1/2 gallons of propane, at close to 4 bucks a gallon it comes out to 6 bucks a day times 180 days on the road boon-docking or a grand total of $720. While $6 a day does not sound like much $720 is a respectable amount, and that is a minimum. If we run the gen set closer to the 4 hours a day the cost could be $2800 for 180 days on the road.
So, with the numbers in hand we went shopping for a solar system to install on the roof of Rover. In the system we included a converter/inverter with a built in 100 amp battery charger, voltage regulators, wiring, and intallation material. The cost was around $2500 delivered to the house.
The second step is batteries. Now here is where we lucked out. We have a battery powered golf cart with almost new batteries, six of them rated at 250 ampere hours each, and as we are not taking the golf cart with us on this trip, it is making a donation to the cause. That means that we will have 3 banks of a pair of 6 volt batteries putting out 12 volts at 750 ampere hours of power, plus the 8D heavy duty truck battery that currently supplies the coach power rated at 250 amere hours, or a total of 1000 ampere hours of 12 volt current available.
Even though the kit has not arrived yet work has begun. The batteries were removed from the golf cart and connected to a charger to top them off. The batteries are going in one of the compartments that used to hold tools. The tools have been transferred to the tool box that we installed on the car trailer last week. We have fabricated vents for the compartment as batteries give off hydrogen gas when being charged or discharged and that needs venting to prevent fires and explosions. The vents are so constructed that they will not allow water, splash from the road, when raining, to enter the compartment. The cables to connect the batteries to the existing circuits have been fabricated and are in the process of being installed. The battery hold down devices have been made and are waiting for the batteries to be installed tomorrow.
The hold downs for the batteries are important. One of the major causes of battery failure is when batteries are not tied down and bounce around. The shock of bouncing damages the plates in the battery and causes failure or internal shorts. So care was taken with the hold downs to be sure that they would secure the batteries properly. The next concern is the weight of the batteries and where they are going. The compartment picked for the job is the one right behind the right rear wheel. This means that the right rear corner of the coach has just become 456 pounds heavier than it was before. This will certainly effect the rear wheel tire pressures but most of all could effect in a negative way the ride height of the coach.
To check this we will measure the ride height and record it. That will for these purposes be from the ground with the coach on a level surgface to the bottom of the rear bumper on each side. We will place the batteries in the compartment and then jump up and down on the rear bumper to settle the coach. Then measure again. Who knows we might have to find a better place for them or split them up. Any difference more than an inch will make me rethink the position of the batteries.
Well next week we should have the system up and running and be able to tell you what probems we ran into along the way.
Till then, keep camping.
Brad & Lucy, and yes of course Kitty Kat Earl