How to count solar panels

Calculation is very simple, mainly knowledge other than calculus.

First, look at how long it takes you to fully charge the battery. Assuming it takes 4 hours to fully charge, then 48/4 = 12A is required per hour, meaning charging is necessary. the current of solar panel is 12A;

Then we know that 18V solar panels are usually used to charge 12V batteries, then the power of solar panel is 108W of voltage for the solar panel;

You can use this method to calculate the wattage of the solar panel according to your own ideas;

Known: 1 hour = 3600 seconds, then 18 / 3600 = 0.005 hours

Answer: 1. Operating power consumption: 3.3 A * 0.005 * 12 V = 0.198 Wh; Standby power consumption: 3.5 * (1-0.005) = 3.4825 Wh;

Power consumption for 18 hours: 3.6805*18＝66.249Wh

2 According to 50% Consider the depth of discharge:

Because as: 66.249/12V/18≈0.31A, 80Ah*. 05＝40Ah

Then: 40/0.31≈129 hours; regardless of the depth of discharge, it is 258 hours.

3. The working voltage of the 25W battery panel is generally 16V because the power consumption in 18 hours is 66.249 Wh,

Then the battery panel: 66.249/12*16/. 4* 1.2=26.4996Wp

25*2 is greater than 26.496, which can meet the demand (may be a bit wasteful).