Solar Math · Solar Panels ·

Which Solar Panel Do I Need?

Overland Solar is the portable solar solution that you can take anywhere.  Each system has built-in charge controllers that are the perfect answer for RVs, boats, remote cabins and camps, expedition vehicles, and really anywhere you want free silent power. But which system is right for you?

 

Before we get started...

Please note that although the battery in your vehicle is 12 volts, it is not designed to have a slow power draw like a deep cycle battery. For this reason, we recommend having a separate deep cycle battery to collect your solar energy. Personally, in my Jeep I have a sealed (AGM) 12 volt battery mounted with an inexpensive 400 watt inverter. Most RVs and boats have deep cycle batteries in addition to a starting battery.

Physics for Everyone: Amps, Volts, Watts

  • Amps: the flow of electrons, used as a measurement of current
    • Think of the flow of electrons like water flowing through a pipe. 
    • The larger the flow, the greater the amps.  
  • Volts: Ohm’s Law says Voltage = Current x Resistance  
    • If you increase the voltage through a circuit when resistance is constant, the current goes up. If you decrease the voltage, the current goes down.
  • Watts:  Power = Voltage x Current
    • Watt is a measure of Power.
    • We carry 4 different solar panels, 60, 90, 150, and 180 Watt Panels.  These numbers represent how much Power you could collect in 1 hr of perfect, glorious, sun.  

Who cares about Physics? What can I charge?

  • A Television uses 3-4 amps/hr. With a 12 volt battery, you could run a TV for about 9 hrs if you had a 90 Watt panel in the sun for 5hrs!  
    • How the math works: 4 amps x 12 volts = 48watts.  
    • Say you had a 90 Watt system charge for 5hrs (450 watts/ 5hrs), you could run your TV for 9hrs (450 / 48 = 9.3hrs)
  • Now you need to roughly estimate what devices you would like to run while on your adventure
  • Some examples: RV fridge uses about 1 amp/hr, 5 LED bulbs use 1 amp/hr, TV 3-4amps, etc.

60 Watt Tri-Fold Solar Panel

  • Most compact system available (18''x41'' unfolded)
  • 10.6 lbs
  • This is the panel I throw in the Jeep when I head to the woods for a couple days. This panel can put out 5 amps into your 12 volt battery (5x12=60Watt!) in 1hr.
  • Examples: Run a couple LED interior lights, watch movies on the laptop, run a small 12 volt fan, and charge a phone.

90 Watt Tri-Fold Solar Panel

  • 25' x 41'' unfolded
  • 17.2 lbs
  • Can put 7.5amps into your 12 volt battery (7.5x12 = 90Watt) in 1 hr (requires perfect conditions).
  • Easily fits in medium RVs, larger truck campers, boats for real world power in off the grid locations.
  • Examples: Run LED interior lights, charge laptops and handheld devices, run RV fridge.

150 Watt Tri-Fold Solar Panel

  • 27''x60'' unfolded
  • 28.6 lbs
  • Perfect panel to keep in your Class B RV (camper van).  
  • Able to deliver 12.5 amps into your 12 volt battery in 1hr.
  • This unit is a great way to watch your flat screen TV/DVD, charge your electronic devices while powering interior lights and other RV components all night.

180 Watt Tri-Fold Solar Panel

  • 33'' x 60'' unfolded
  • Weight: 35.25 lbs
  • Deliver up to 15amps/hr
  • Plenty to power for larger boat and RV battery banks.
  • As with our other panels, the ability to simply move the panel to face the sun a few times a day can effectively double the amps to the battery
  • One customer decided to buy two 180 Watt Tri-Fold Panels for his large 40 foot RV after comparing the cost of a 400 watt system to be installed on his roof. Overland Solar’s product was a quarter of the cost and instead of a 400 watts system (giving him ~160 amp hours), he can move his two 180 watt portables a few times a day giving him 300 amp hours. Almost DOUBLE!

Disclaimer:

It is impossible to exactly determine the quantity of solar power collected. These numbers are derived using laws of physics and are based on perfectly sunny conditions. Even on the sunniest day, an occasional cloud will slightly decrease total solar energy collected. Our panels still generate power on rainy, cloudy days (I live in Seattle and am familiar with said weather conditions). This makes it exceedingly important to be able to move the panels throughout the day to follow the sun (something that cannot be accomplished with roof mounted solar panels).

Most importantly…

Overland Solar provides endless power and freedom.


Back to News