Solar Power for your RV
Solar power with your RV provides the ability to go “off grid”, dry camp, be out in the wilderness – and STILL enjoy some of the amenities of “modern life”. RV Solar power can be a worthy goal, but there are pitfalls. If you read Tom Dansby’s excellent article on the topic of RV solar power, you’ll note he starts by recommending Solar Bob’s blog. Having read Bob’s blog, I began to become dejected as I saw adding solar power to my RV as a major (and expensive) project – one where many installers were not skilled sufficiently to insure the job would be done right – and I for one did not feel that I had the expertise to execute well on my own.
Note: I’m updating this RV Solar Power article on 9/22/16 to correct an error I was made aware of and to add some additional experience as I am back “on the road” and have spent a bit more time “dry camping” – and plan to do much more soon!
All that changed when I started to consider PORTABLE solar power for my RV…
Portable means you park, you take out your solar panels and you point them towards the sun, period, done, fini! The upside – no involved install on the roof of something you may not keep forever. No concerns over how and where you park (what if you’re under a tree in the shade and you have solar panels on the roof??). No involved wiring from the roof to the batteries. The downside – your solar panels *could* grow legs and walk! (But so far, that just has not been a concern.)
My approach had me “out the door” for a total cost of $1092. Each time I dry camp, setup time requires a grand total of about 5 minutes! There are NO installation costs or headaches associated with my approach. Allow me to share by video, then you can see the specifics on what I purchased and why I selected each piece within the entire setup.
Lets break down the components of my solar setup…
I used to have a set of 6v AGM batteries. After about 2 years, one went bad. I reverted to a cheap 12v deep cycle that I knew would NOT do the job with solar panels, so I went to the workhorse, old steady of the industry – Trojan 105-RE (click link for recommended vendor at best price). My total cost by going through “The Solar Biz” (including delivery charges to Billings, Montana was about $350.) These (2) batteries are wired in series, providing 12 volts to my RV and deliver 225 amp hours of energy.
Renogy makes great solar panels
I chose Renogy (link goes to the new 100w system, read on for info on the 200w system) for my RV Solar Panels based upon their reputation and cost. Their reviews are STELLAR and their prices blow away the competition. You’re able to connect (by alligator clips) up to 2 100 watt “suitcase systems” to one set of batteries – in essence providing 200 watts of power to the batteries and my RV. Each comes with a solar controller (the thing that controls how much voltage / current is sent to the batteries). It is easy to set up and provides a current readout – which at peak sun (in Montana in September) produced upwards of 5.7 amps from each suitcase, so the total production (at peak) was 11.4 amps per hour. Renogy also has a GREAT tech support department easily accessible by phone – and they walked me through the initial setup in minutes!
The links provided in the images and text above and HERE will enable you to learn more about the Renogy suitcase panels and see Amazon’s price on them. (Full disclosure: I am an Amazon affiliate, if you plan to purchase – using my link will not cost you any extra, but it does help to cover my costs for bringing this website to you.)
Each suitcase system includes a well… suitcase which is very slim and easy to store when the panels are not in use. Also – the panels ARE not injured by water (if it starts raining), but the solar controller should (and can be) easily sheltered. When it is cloudy, very little current is produced (well under 1 amp per system), so don’t leave the solar panels out when rain threatens.
My only concern regarding these panels is the fact they only come with 10 ft. cables and maneuvering the panels to “see” the sun is sometimes a challenge. They do however have quick disconnects called “MC4” cables. (see photo)
I just ordered (for about $68.) cables that will extend each solar suitcase to a total of 20 ft from the batteries. I believe this is plenty of room to move in almost any situation. The cost for using extender cables? 1.5% power is lost in the extra 10 ft. of cabling – but with some creative adjustments (tech support will help) in the solar controllers, the batteries can STILL be charged as the panels have a max output of 19 volts.
IMPORTANT – There is a 200w system (approx cost $640) coming VERY soon. For those with greater energy needs, it will be a GREAT solution. It is not yet available as I write this.
Generating Power is great, but what was I going to do with it?
My needs when I’m “off grid” are simple. I want to be able to run the furnace overnight (if needed). Run lights when needed. Keep my cell phone and laptops charged, and run on occasion a motor for my air mattress and my water pik. I have no need (nor expectation) to run the microwave, A/C, or even a TV (I get most of my tv through the computer anyway). With those goals in mind, I settled in on a Wagan 400 watt pure sine wave inverter.
Monitoring the System
Here is where the purists will disapprove! Instead of a trimetric 2030 (the industry standard for monitoring your batteries to see how they’re charging/discharging), I elected to forgo the (approx.) $200. cost (with required accessories) for my system. I opted for the Innova 3721 battery system and charging monitor for a grand cost of about $13 bucks! Update: I also (finally) purchased a simple digital multi-meter so I can test at the battery terminals directly.
Here is my reasoning: Using my 12v (cig lighter) receptacle next to my bedroom TV I can monitor voltage. Here is what I found:
Typical voltage measured during the day during peak charging hours: 14.36 volts (as much as 14.63 has been observed by taking randomly timed measurements)
Typical early evening voltage (with all lights off and nothing plugged in): 12.92 volts
Typical early morning voltage (after a night of keeping my phone and 2 laptops charged AND periodically running lights on): 12.29 volts
Lowest observed voltage (after a night where the temperature dropped to the high 20’s and the furnace ran off/on much of the night): 11.95 volts
What does all this mean (to me)? Well, it is my understanding that the batteries are 50% discharged when they are producing 12.2 volts. Note my lowest was 11.95v (using the remote 12v testing device). The next time I experience these conditions, I will check the batteries directly on their terminals to see if in fact I’m dipping under the 50% discharge line. Again – this dip occurred only one night, for a few hours as the furnace was running frequently and temperatures dropped into the 20’s. Naturally my first concern was to avoid any kind of freeze in my plumbing!
Rather than wire a trimetric – a wiring nightmare in my view – into my system, I have chosen to rely upon this basic voltmeter and do what it takes to stay over 12.2 volts. I have now tested the system on three separate occasions – for one day, then for 5 days, then for 4 days. On the longer tests, I can affirm I am “self-sustaining” – using as much power as I produce as each morning the voltage was amazingly close to 12.29 volts. The only exception was the night I opted to “hammer” the furnace to keep warm and that did push the voltage under 12 – a voltage level – and temperatures with no hookups – I’d prefer to avoid.
I give credence to “solar bob’s” words of advice – but I then yield to those who have installed many solar setups and have a track record of satisfied customers who are not even adding in the voltmeter that I purchased. I decided I did not want to “fly blind”, but did want to insure I had some way of measuring the batteries output – but by a method that did not involve adding new wiring from the battery box to the living quarters of my RV.
In closing… I hope you found this information helpful. I’m here to provide real-time feedback and I appreciate yours in the space provided below…