How Much Solar Power Do I Need For My RV?
By Pete | My Husband’s Corner
These RV tips and hacks are essential for going solar! If you have been hanging around here for very long, you probably know we do a lot of boondocking. When we decided to take longer camping trips we needed to re-think our power needs so I asked myself the question, “How much solar power do I need for my RV?”
I realized answering the question was more complicated than I expected … BUT … that is good news for you because I created this simple RV solar calculator to determine the answer!
Psst we’re compensated…see our disclosures.
How Much Solar Do I Need?
Here’s how we determined the amount of solar power we needed for our RV boondocking trips … and recommend you do the same.
- Go boondocking and ONLY use your RV battery(ies) as your power source
- Operate all of the electrical equipment in the same way you want to operate it while using RV solar panels (normal usage here, no conserving so you get a true reading of how much power you will need from your solar panels)
- Determine the number of days you can operate before your batteries are drained
- Your RV batteries have a certain amp hour rating … that number indicates the total capacity of the battery … but, you can only use around 75% of that capacity because the voltage drops to a level that will not provide power at a necessary level. For our experiment, we have two group 24 lead acid batteries, each battery has an 80 amp hour rating.
Here’s the math for our RV batteries that are in good condition:
- 80 amp hours per battery x 2 batteries = 160 total amps available from both batteries
- 160 total amps available x .75 capacity = 120 total true usable amps from both batteries.
- 120 total true usable amps from both batteries / 4 days before our batteries were drained = 30 amp hours per day average need
Knowing how much solar power you need for your RV is directly related to maintaining the best RV battery health you can, so, check out our other post, How To Choose, Use And Maintain The Best RV Battery.
Knowing our typical demand:
- Now we know our typical demand is 30 amp hours per day.
- The next question is, what size solar panel has the capacity to meet our demand, that depends on the sun.
- This is also important information if you want to use AC power from your outlets when you’re off the grid. You’ll need to know how to install a power inverter in a camper.
What the sun will provide:
A 100 watt solar panel produces approximately 6 amps per hour in direct summer sun without clouds.
Assuming we get 5 hours of direct sunlight, we know a 100 watt solar panel will produce 30 amp hours per day.
For our experiment, 5 hours of direct sunlight without clouds x 6 amps generated per hour = 30 amp hours per day that the solar panels are generating to recharge our RV batteries.
Our determination:
How much solar power do I need for my RV? Our final personal determination: For our specific power demands, we need one 100 watt portable solar panel to recharge our RV batteries during our boondocking camping trips under normal conditions.
For reference:
- We have all LED lights, as we discuss in our camping lights post.
- Moderately use the RV water pump.
- Rarely use the RV heater.
- Play CDs with our RV stereo system a few hours each day.
- Charge three personal electronic devices.
- Occasionally operate a laptop computer.
In other words, we are relatively conservative concerning our power usage.
After you print your FREE copy of our RV Solar Calculator (below here), you can learn more about our decision making process in our Portable Solar Panels For RV Camping VIDEO post which shows you how to set-up, monitor and use portable RV camping solar panels.
Print This RV Solar Calculator
How To Determine: How Much Solar Power Do I Need For My RV?
Materials
- RV with its normal batteries
- Electrical equipment you want to operate using solar power
Instructions
Determine the amount of solar power needed for RV boondocking
- Go boondocking using your RV battery(ies) as your ONLY power source
- Normally operate all electrical equipment. (Note: DON’T conserve … the demand load must be accurate to get a true reading of how much power your solar panels must produce)
- Note the number of days before your RV batteries are drained
Here’s an example for our RV batteries
- For our experiment, we have two group 24 lead acid batteries, each battery has an 80 amp hour rating.
- (Note: RV batteries have a certain amp hour rating indicating the total capacity of the battery. Approximately 75% of that capacity can be used because at a certain point, the voltage drops to a level that will no longer provide power.)
The math to calculate how much solar power you need for your RV
- ____ amp hours per battery x ____ number of batteries = ____ total amps available from your RV batteries
- ____ total amps available x .75 capacity = ____ total true usable amps from both batteries
- ____ total true usable amps from both batteries / ____ days before batteries were drained = ____ amp hours per day average need
- Here’s an example of our math for our RV batteries that are in good condition
- 80 amp hours per battery x 2 batteries = 160 total amps available from both batteries
- 160 total amps available x .75 capacity = 120 total true usable amps from both batteries.
- 120 total true usable amps from both batteries / 4 days before our batteries were drained = 30 amp hours per day average need
- Now we know our typical demand is 30 amp hours per day.
What the sun provides
- 100 watt solar panel = approximately 6 amps/hour in direct summer sun (no clouds)
Here’s an example of our calculation of how much the solar panels are generating to recharge our RV batteries
- 5 hours of direct sunlight x 6 amps generated/hour = 30 amp hours/day
Our final determination
- Our need: 100 watt portable solar panel.
Notes
After I answered my question, How Much Solar Power Do I Need For My RV?, I began to research solar panels that would be able to meet our power demands.
We ended up purchasing a Renogy 100 Watt Solar Panel Suitcase and we love it!
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If you are asking yourself, “How much solar power do I need for my RV?” it is probably because you are thinking about doing more boondocking which is what we do almost every single time we camp!
Our Boondocking Setup
Check out our video: The Perfect RV Boondocking Campsite Setup!
What do you think?
Leave me a comment, question or suggestion below. I’d love to hear from you so let’s chat.