- The boat has two deep cycle wet cell battery banks; 240 amp hours and 120 amp hours.
- The boat has holding plate refrigeration which draws 5 amps. The weather was very warm so the frig compressor ran more than usual; 8+ hours a day. The lap top computer was used for navigation and draws 5 amps. Most lights are LEDs.
- When motoring, the panel was usually disconnected from the controller so the smart regulator would get an accurate reading of the battery bank condition thus achieving max output from the alternator.
- The dual bank controller shuts off power from the panel when the batteries are fully charged. i.e. After 4 or more hours of motoring.
- The Remote Display of the dual bank controller was used to collect all the data.
- Our mode of cruising was to anchor for 2-4 days at a time and move on to another anchorage. We did not dock and use shore power during the three week cruise.
- The tilt angle of the panel was rarely changed; usually about 45 degrees. The panel was rotated for optimum sun angle about 4 times per day.
Date Amp Conditions of the day
7-7 46 At dock, shore power on
7-8 39 Motored 4 hours, partly cloudy
7-9 17 Motored all day, cloudy tried solenoid
7-10 26 Cloudy, motored 1 hour, sun 5-6 hours
7-11 55 Mostly sunny, travel day – under sail
7-12 64 Mostly sunny, at anchor
7-13 79 Mostly sunny, at anchor, reset meter when rewired batteries
7-14 70 Mostly sunny, at anchor, panel not turned for part of the day
7-15 49 Cloudy morning, sunny afternoon, motored for 2 hours with solenoid on
7-16 51 Mostly sunny, motored 2 hours with solenoid on, topped off batteries
7-17 34 Mostly cloudy, at anchor all day
7-18 47 Mostly cloudy, motored 2 hours
7-19 20 Hazy, cloudy, motored 2 hours
7-20 71 Sunny, at anchor
7-21 80 Sunny, at anchor
7-22 67 Mostly sunny, ran engine 1.5 hrs, topped off batteries
7-23 39 Mostly cloudy, at anchor
7-24 73 Mostly sunny, at anchor
7-25 68 Mostly sunny, at anchor
7-26 16 Hazy, cloudy, motored 4 hours, topped off batteries
7-27 26 Cloudy, hazy, motored 9 hours, batteries charged
7-28 42 Mostly sunny, motored 2 hours with panel connected, batteries charged
Definition: amp hour – amps produced or consumed in one hour
Average amp hours per day produced under various conditions:
Overall (22 days) 54 amp hours
Sunny days at anchor 71
Cloudy days at anchor 37
All days at anchor 62
Days engine was used 35
Max amp hrs for a day 80
Min amp hrs for a day 16
Max amps output 10.5 amps
The 130 watt panel generally met our power needs for the duration of the cruise. We occasionally ran a small deficit of amp hours during an extended anchorage but never used the engine alternator to charge the battery banks except when motoring from place to place. On days when the engine was used we often had an excess of power generation from the 75 amp alternator and the 130 watt solar panel.
The solar panel is very sensitive to cloudy days and to shadows. The panel output on sunny days exceeded it rating. This is the nature of mono-crystalline solar panels.