The charge controller is a part of all solar or wind energy sytems. A charge controller is needed for your system. It is connected to your batteries and the panels. Our charge controller was mounted on our wall. Now it is downstairs in the cellar There are many different brands and types and it can get complicated. I am not the most knowledgeable person on this subject. I just know what we use and how it works. We have had all together three different ones.
The charge controller does just what the name says. It controls how much of a charge that goes into your batteries. It will stop the charge coming in from whatever power source you are using when your batteries are at full charge. It would ruin them to be overcharged. In the beginning with only two lead acid batteries and one 55 watt solar panel using this small charge controller was fine. At that time we used to charge the batteries with a car parked next to the window. I remember being able to do this myself. Using jumper cables.
As our system grew we added a better type of charge controller. It is made by Xantrex, which was a good quality brand. We used it for many years and still in fact, have it. This one was able to be used as our system grew. My husband always planned on adding a wind turbine so he kept that in mind when purchasing our various components. Each component is costly so you want to make sure that what you buy will be able to be used as you build your system larger.
Once we had the wind turbine up we had to make sure our charge controller could handle all the extra power. It took us a long time to get the turbine up. I will be posting about that on a future blog post. Once we got it up we had to do something with all that extra power. That brings us to our present charge controller which is a diversion charge controller. It does not mean it cuts off from the charging source when the batteries are at full charge. It keeps charging but will direct that energy somewhere else. It has a built in heater that turns on to use the power up so it won't over charge the batteries.
It was on our wall while the batteries were up here. Now they are downstairs in the battery room with the new the batteries. This controller will be hooked up to eventually sending the diversion load into our water heater that will heat the water instead of turning the heater part on. We have a brand new water heater and a pressurized water tank in the water room just waiting to be hooked up. I can't wait for that myself! That means that we will have running water in the house. I am promising myself that we will get it in this summer for sure. I have a brand new washing machine all hooked up and ready to wash.
The most important part of any off the grid energy system is the battery bank. The energy (or power) comes from the sun (hydro, or wind, or wind and sun both, as in my case) through the solar panels or wind turbine then goes through the charge controller and then into the battery bank. The charge controller does just what the name says, it controls the charge going into your batteries so they do not over charge. If the batteries are already at full charge, our charge controller, which has a diversion load on it, that means it diverts the power to another element. This charge controller has heating coils on it so the extra power goes to that. Eventually it will be hooked up to the water heater and the extra power will heat our water. At present our water is not piped in the house yet. Hopefully that will be done soon. Our plan is to have water collectors on the roof of the house as well as the electric water heater in the cellar.
Back in 1999 when we moved here lead acid batteries were the best option for off the grid home set up. We started out with two and added two more later, even though the experts say not to do that. They say it will cause your batteries to have a short life. Contrary to that advice, our batteries were great. Never had a problem with them and when we replaced them years later, they were still usable. We gave them to friends of ours who used them for their golf cart on their homestead. Those lead acid deep cycle batteries were 6 volt, which were sold for fork lift trucks at my husband’s place of employment at the time. So we got a good deal on them with his employee discount. I am sorry I don’t have any photos of those batteries but at that time I did not have my digital camera and I couldn’t afford to buy film then. Those were tough times getting started here.
A few years later my husband designed a website and I listed products for a friend, who was a solar installer. He paid us in giving us 24 lead acid 2 volt batteries that he was given by a customer who was switching over to being grid tied (connected to the electric company grid with no battery bank). These batteries were very clean. The plates had no build up on them at all. They originally had been used by the railroad and then the homeowner, of course. So we were the third owners of them and they worked flawlessly for over ten years.
It was just in this last year they started not holding the charge very well. They still didn’t look dirty inside, but they could have been. They needed to be equalized and we had no way to do that process. By putting each battery on an automotive battery charger and letting it trickle charge (very slowly charged) for a couple of days or however long it takes till they reach full charge. Then let it sit for a couple of hours with no load on it. After that it needs to be tested with a hydrometer. I imagine they can be sold to someone who is on the grid and has the power to do that. We could not carry out that process here.
When these batteries were charged, I would hear them bubbling all through the afternoon and night. That bubbling is what cleans the plates as it chips away at the sediment on the plates. Eventually the sediment will settle on the bottom of the battery and build up over the years. Someone can empty the battery out and clean the inside by hand. Then refill and charge. It is a lot of work, especially for 24 batteries, but can be done. We just couldn’t do it here, or knowing my husband, he’d have done it.
Since the batteries are the heart of our system, keeping them clean and filled with distilled water was essential battery care. Testing them, dusting them off and paying attention to them was important to keep our system running. These batteries served us well. I am proud to say we never abused them or misused them at any time. My husband is very critical of every element of our alternative energy system, especially including the battery bank. About a month ago we replaced those 24 lead acid batteries with 2 LifePo4 batteries from Battle Born Batteries. We were using our generator daily due to the batteries not holding the charge any longer. Using the generator is the last thing you want to be doing! I will be writing more about these batteries in a future post as I learn more about them. We plan on adding to the battery bank with more of these new batteries. The nice thing about them is you can add to them one by one if you need to. Yes, two of these batteries have replaced our 24 lead acid ones! If you are curious about how that works, keep an eye on this blog because I will be telling you about it soon.