Solar Panel Calculator

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As a general rule, you will need 10 watts of power for each output joule of your fence energizer. For example: 3-joule energizer = 30 watt solar panel. Use the calculations below to determine wattage needed for your energizer and location.

calculateAhperDay
Step 1: Calculate the Ah per day needed

Determine wattage of the unit.
Battery voltage x Energizer amps = Watts
12v x .29A = 3.48W
Watt hours = 3.48W x 24 hours = 83.52Wh
Determine Amperage Hours
A= W/V
Ah = 83.52WHr/12V = 6.96 Ah per day

Step 2: Determine peak sun hours for your location.
For example, average sunlight near Blairsville, PA = 3.68

PeakSunlightHoursMap

Step 3: Calculate which solar panel will provide the Ah per day you need.

Now divide the Ah that you need (from Step #1) by the number of Peak Sun Hours per day

Example: 6.96Ah/ 3.68Hr = 1.891A

This means that a panel that produces 1.9A is what you want. Determine Panel Size:

A = Watt/Volt
Watt = Volt x Amps
? = 12V x 1.9A

=22.8 Watts - Always add 20% to take account the real world conditions.
=27.36 Watt Panel - Round to 30 Watt Panel.

Unit (joules)
Amp (energizer)
Wattage (energizer)
Wh used per day (energizer)
Ah per day (energizer)
Voltage Battery
Sunlight Hours
Amps Needed
Solar Panel (watt)
1J
.10
1.14
27.36
2.28
12
3.68
.62
10
2J
.18
2.16
51.84
4.32
12
3.68
1.17
20
3J
.29
3.48
83.52
6.96
12
3.68
1.89
30
6J
.7
8.40
201.60
16.80
12
3.68
4.57
70
12J
1.1
13.20
316.80
26.40
12
3.68
7.17
100

Battery Recommendations:
Deep cycle batteries are recommended for solar powered fence systems. These batteries are designed to be discharged over a long period of time (100 hrs.) and recharged hundreds or thousands of times. To maximize battery life, deep cycle batteries should not be discharged beyond 40-50% of their capacity. For example: A 3-joule solar fence energizer would work without sunlight for 8.6 days and only use half the capacity of the battery.

Solar fence products
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