by admin | Jan 11, 2014 | Tech Updates
By: Jerome Auza Last week was a very good opportunity to test my small solar energy system and how it would fare in cloudy weather providing power for two computers. I started with fully charged batteries on Monday connected to a 600 watt pure sine wave inverter and two laptops with 65 watts and 85 watts power supplies. I guessed that the two laptops will only consume half of their rated power consumption during use between 9AM to 6PM and would be on standby during the night and therefore consume little power. The 100W solar panel should be enough to power them during the day and keep the batteries charged assuming the panel gets enough sunlight. But it was cloudy and rainy most of the week. The setup worked fine until Friday morning when the inverter shut down due to low battery voltage. At 9AM, I can see that the batteries have charged up a bit so I turned on the inverter and plugged the 85W laptop only. By noon, the inverter shut down again which means the power generated by the panels is not enough to power the laptop and the inverter, thus draining the batteries. The weather was still very cloudy. I let the batteries charge until Saturday without any load but by 5PM Saturday, the battery is still considered less than 40% charged based on the indicators of the solar charge controller. The weather, was still cloudy most of Saturday. This got me into thinking that I should be able to see if my setup is charging or discharging the batteries when a load is applied....
