Maintaining And Replacing The Solar Batteries

Batteries Come And Go

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Our solar batteries have been dying, over and over, through the years. We have come to learn that the primary reason has been the summer heat. This has only recently become clear to us. There were other reasons at times, more readily obvious, and some that were not. For most of the time it has been elusive and confusing, mysterious, as to why some, or all, would weaken and die.

In May of 2017, while topping off the batteries, I discovered that one was completely dead, so I immediately bought a replacement in town at AutoZone (for $144) and installed it. Then I hopped the plane to return east for the summer.

After our return in November I topped off all of the batteries. Some did not need any water which is not a good sign. Some were showing metal above the acid/water line and that is not good. Three weeks later about half tested bad so I removed eight of the worst. My 16 battery system is comprised of two 48 volt DC strings. It is okay to remove one string in a pinch. The bad ones are like rotten tomatoes; they can pull the good ones down to their level.

I immediately went looking online for new GC-2 "golf cart" batteries and found a good deal at solar-biz.com. $1760 for 15 brand new Crown GC-2 6 volt batteries that were getting good reviews. That included shipping. 15 of the same at AutoZone would have cost $2160, plus shipping (gas in my car).

I then built a solid but removable ramp from the driveway up to the deck, wide enough for my hand truck. Good thing I did that. When the load arrived on December 12, the trucker absolutely refused to help.

By the end of the day, the new double string 48 volt system was up and running and it was a beautiful thing. (Our Outback Inverter inverts the 48V DC into 110V AC.)

So now I had 15 batteries sitting on the edge of our driveway. I kept two with good readings as spares. A week or so later, I put five into my car and took them to Morongo Basin Recycling in town. The owner, Roberto Plascencia, paid me $123 for 13 batteries and then followed me home in his pickup to retrieve the rest.

In early February I completed hanging an almost air tight floor-to-ceiling enclosure of semi-insulated "Grabber All Weather" blankets around the batteries, the solar electronics, the computer and the air conditioner. This was designed to keep the desert heat out while directing all internal heat towards the AC as its cool air flowed into and around the forementioned objects. Heat tends to rise; cold air tends to fall, hopefully to settle and flow around the batteries.

I topped off the batteries on February 6 and they didn't need much. "Topping off" means untwisting each of 48 cell caps, three cells to one 6 volt battery, looking inside each with a flashlight, and filling with distilled water being careful not to let it overflow.

I did so again on March 12, five weeks later, and they were fine. I don't know why I was being so conscientious.

In early April I completed the installation of a canopy over the front of the solar utility house which will keep that front in complete shade during the heat of each day throughout the summer.

The final topping, the only one that really mattered, was done on May 7. Two days later, I was heading east.

A dozen times through the summer it did reach above 100 degrees, always in the evening after the AC had been shut off by its timer.

On our return, I am going to add two hours to that timer. Even if that consumes too much power and causes it to shut down, it will recover when the sun hits the panels in the morning. However, the computer probably will not recover on its own, so I'd rather that not happen.