Monday, June 10, 2013

Our Solar Update

Hubby lining up the new batteries in the box. 
We ended up replacing the battery bank. The batteries, L-16's, were 6 years old. Everyone was telling us that 6 years was average lifespan for them.  Well, we guess that 6 years is ok since we are still learning about caring for batteries, but we hope to do better with this new bank of batteries.

The new batteries starting to be wired. 
When we went to Interstate Batteries to buy a good quality hydrometer, we had the opportunity to talk briefly with the battery tech. We learned quite a few things. First, check batteries with a hydrometer right after they have had a good charge. Second, we will be able to recover, thus use, the four best batteries of the old array. We plan to use them on a different project. The four lesser quality batteries most likely not worth putting the effort into them because of the amount of power that would be needed to recover them. We plan to give them to a friend who has a very large solar array and thus has the capacity to shock them good. Maybe he will be able to recover them enough to use them for something.

We ended up replacing the battery bank with 6 volt golf cart batteries, instead of L-16's. Reason....they are a lot lighter and easier for us to handle. Frankly, we are just too old to tote around L-16's anymore. We purchased 8 batteries because we will be moving the Stecas off to their own system (4 batteries). We already have the right number of solar panels up, so we don't need to change that. The system for the Stecas will have their own four panels. By the way, we use unisolar panels. We opted for them because of the sun situation we have here. We live in a forest (thus panels can get partially shaded during the day) plus the days are often bright-overcast rather than clear sun. the unisolars are better under these conditions.
The old L-16 batteries. 

Back to the action.... we managed to lift four of the L-16's out of the battery box and into a storage shed. After that we were pooped, so we left the other four in the box for another day. We still had plenty of room to install the 8 new golf cart batteries.

Our system is set up for 24 volts, so we wire 4 batteries together in a series. Then the two groups of four are wired together parallel. All that use to be a foreign language to me, but I'm finally understanding that stuff! 


  1. That looks like it is literally backbreaking! Would it be possible to push a transmission jack, or engine hoist close enough to hoist up the batteries? In home care settings, there's commonly used lift, called a Hoyer Lift, to move patients from their bed to a wheelchair or shower chair. Might watch for one on craigslist or swap meets, might help. The pace of all our technology has been so fast - except for battery tech. Lead/acid is so archaic compared to electronics. I salute your growing expertise with your off-grid energy management!

  2. If we owned a hoist, then we could have used it. Guess we could have asked around to borrow one. But our thinking has gradually become self centered, looking towards ourselves to get something done. And we are looking at the future. In around another 6 years, those new batteries will be up for replacement. So we have opted for a battery that we can readily handle.

    Over time, we have come to use less and less electricity. So really, L-16's are overkill for our needs. The golf cart batteries will do nicely.

    Lead/acid is archaic, but they do the job at a lesser cost than other batteries. Down the road from us some people bought lithium batteries because they were told they were maintenance free. Those folks knew nothing about solar, so the sales pitch sounded great to them. Anyway, they paid through the nose. And it turns out that the batteries didn't last.

    There are indeed other batteries out there that work better, last longer. But the cost is extremely higher. And availability is difficult for Hawaii. L-16, marine, and golf cart batteries are readily available here. Our golf cart, 6 volts, cost us $88 each. Far, far cheaper than L-16. And over years, it will be considerably cheaper to go with the golf cart batteries, at least for now.

    Thanks for the compliment about our growing expertise. Learning about solar comes from necessity. While we read everything we can, there is still much not published about solar systems and battery care. But we are learning, on the job, so it goes. Plus we are learning to use less!!!!

  3. Yeah, you are wise to stay with lead/acid batteries. I read somewhere that those huge batteries in Prius and other cars are being "re-purposed" for home battery service, but too bad for the poor sap who pays $3500-4000 for a car battery every three years. I'm sure that natural gas won't come to Hawaii anytime soon, with reason being "?earthquake danger" (Southern California Gas thinks differently. I hope the technology catches up someday!