My Work: Living on Solar Power - Part 10

Dec 2002

Despite all our improvements, we still weren’t getting the performance out of our system that I thought we could. The NiCads were tough, but they were 40 years old and even jumping out the weak one in each string didn’t improve them as much as I had hoped. Plus, 100 batteries took up a lot of room and I was getting tired of recording the voltage on each one every month or so and adding water every three months. So, an unexpected, very lucrative writing contract started me thinking about batteries.

After much research we decided on Surrette lead-acid batteries; a Canadian company with a good track record (www.surrette.com). They had several different models, but the distributor I called recommended one that was not on their website: 2V, 2770 amp-hours. That sounded pretty good to me since we were operating on about 400 amp hours at the time.

They were 31 inches high with an eight inch-square footprint. That would require some modification of our battery cabinets, but they would take up one-fifth the room of our NiCads. Six batteries to replace 100. Sold.

We installed them with Hydrocaps that capture the hydrogen normally given off during charging and return it to the battery, cutting down greatly on the need for adding additional water. Six times the capacity, a 10-year guarantee, less maintenance, and less space. Ain’t technology grand?

I was a bit sad to leave the land of NiCads for lead-acids — it was the same feeling as replacing the kid’s aging Macintosh with a DOS machine, but I saved the best 20 NiCads for the barn, just like I refuse to give up my own Mac.