System Sizing by Actual Use
RV, BOAT or Off-
Our recommendation is for you to go out and "boondock" in your RV, Boat, Off-
Let's say you were able to "boondock" for two days before you noticed your batteries getting weak.
First we have to determine what your batteries storage capacity is. Let's say you have two (2) relatively new Group 27 deep cycle batteries that are rated at 100 amp-
Once we have established what your batteries storage capacity is we divide it by the number of days you "boondocked" (in this example it was 2 days). So, 160 amp-
Now we need to determine how many solar panels you will need to replace that 80 amp-
A 100 watt panel produces an average of about 6 amps per peak sun hour, or about 30 amp-
Given the above example, you would need three 100 watt solar panels to fully recharge on the average day.
It is our experience that most Boater,Rvers or Off-
A further, highly recommended approach would be to purchase and install a Battery Monitor.
These devices record your consumption and give you a reading that tells you how many amp-
System Sizing by "Rules of Thumb"
BOAT, RV, Off-Grid Solar System Sizing by If you are unable to go "solar junkies" in order to determine how many amp-hours you consume on the average day, then using the following "Rules of Thumb" works fairly well also:
1. Use a minimum 100 watt solar panel for basic battery maintenance on Trailers and Fifth Wheels. (See our Bare PV Solar 100/10)
2. Use a minimum of 200 watts of solar panels for basic battery maintenance on MotorHomes. (See our Bare PV Solar 100/20)
3. For the more Conservative consumers of electricity: Allow 200 to 300 amp-hours of Battery Storage Capacity and 200 to 300 watts of Solar Panels. (See our DIYSolarWareHouse 100/30/10 or our DIYSolarWareHouse Solar Plus 100/25/8/6/Pro+)
4. For the more Liberal consumers of electricity: Allow 400 to 600 amp-hours of Battery Storage Capacity and 400 to 600 watts of Solar Panels. (See our DIYSolarWareHouse Solar Plus 100/45/4/2)
5. For "Hard Core" Solar Junkies with Mobile Offices: Allow 600 to 800 amp-hours of Battery Storage Capacity and 800 to 1000 watts of Solar Panels. (See our DIYSolarWareHouse Solar Off-Grid Plus2 100/60/2/2)
Bear in mind that you can start with one or two solar panels and add more later if needed. This is made quite easy with our DIYSolarWareHouse System Cores and the use of one of our Combiner Boxes.
**Below is a great tool from Midnitesolar to size your strings**