The solar batteries’ charge didn’t catch up yesterday. So this morning, I wait, drinking coffee in the dark, for the sun to come up. More of a pain than anything else because I have to find a place to prop a flashlight or just do everything one handed.
I’ve mentioned the issue of our solar system “faulting out” in several previous posts. I’d like to get a little more specific on this issue so if/when any of you set a system up you might save yourself a few headaches and dark evenings and mornings!
Our system consists of 3-15 watt panels, 2-12 volt car batteries, a charge controller, wires, 2-12V lights, and an inverter. For this post we need to talk about batteries and the charge controller.
Below is the type of charge controller we have.
The overall charge of the batteries is shown via the red LED display. We make use of the 12-V inputs and the inverter plug.A brief and very basic aside-just in case you don’t know (I didn’t before I started messing with this stuff) An inverter converts or rather inverts DC (direct current) to AC (alternating current). Most of our electronics and appliances in the US run off of AC power. It is the type of power that comes out of your wall outlets. Your car’s electrical system, just like our solar set-up, is a DC system and is powered by a battery. When you plug your phone in to charge in your car you are using an inverter.
Back to the controller…A charge controller’s job is to maintain a battery’s charge; to not let it get too low or too high. Both conditions in the world of batteries equals damage. In the case of low charge; early battery death. In the case of overcharge; fire and/or battery explosion.
The optimum battery operating range is between 11.7-14.5 volts. If the batteries’ charge is above or below this range the controller shuts the system down. If above it won’t allow anymore charge to come from the panels. If below, it will not allow the batteries to be used. This condition is what I am referring to as faulted.
The manual says 11 volts-my experience says anything below 11.7 and my lights don’t work.This morning it read 11.4.
Difficulty maintaining a good charge has been an issue every winter. The assumption is (at least it was ours before living with solar power) that if the sun is out, batteries are charging. That is not completely untrue, even with limited light they do charge some.
However, one of the differences between full charge and slight charge is the quality of sun light.
I never considered quality of sun light before but have found it is an important factor in using solar.
Solar panels gather energy from sunlight. Then some magic that can only be explained by physicists occurs:
Anything that gets in the way of those sun rays impedes the collection process. In our case that would be hazy, partial or full cloud cover.
I took these pics this morning and this was the way the sky was all day. Tonight I checked and my system had gained .3 volts and is still in low voltage/unusable mode.
Tomorrow will be more haze and clouds and I do not expect to gain much in the way of charge.
It’s time to do some research to determine if we need more batteries or more panels or… My husband and I have been talking about this and are both beginning to believe something larger is amiss, although we are not sure what. I will post updates as I find them. If you, my friendly readers, have any suggestions, please feel free to post them in comments!