First off, if you’re unfamiliar with Lindsay Publications, get yourself acquainted. Unforunately, they’ve ceased to publish books, but copies can still be acquired online. Their collection of books is a treasure trove of Maker knowledge from yester-year, and “Secrets of Lead-Acid Batteries” is no exception.

I first came across this book while taking a course in sustainable energy at ITP. I possessed several car batteries I had accumulated over the years and I wanted to put them to good use. This book was an invaluable resource in helping me to identify whether the old batteries had value in terms of storage capacity, and how to rejuvenate them to be put back into good use.

The technology behind lead-acid batteries has been largely unchanged for the last hundred years, and the batteries themselves are so pervasive because they’re easy and inexpensive to manufacture. Author T.J. Lindsay sifted through reams of ancient publications and distilled them into a practical 48 page manual for folks looking to use these batteries as an alternative energy source. It was first published in 1979, at the peak of the back-to-the-land movement.

The book starts with a brief explanation of the chemistry behind how lead-acid batteries work. He explains that with proper use, a lead-acid battery should have a relatively long life. The problems come when the charge and discharge cycles are stressed beyond their recommended rates. This damages the plates within the battery and lowers their efficiency.

However, lead-acid batteries that are damaged can often be at least partially restored through various recharging and discharging methods. By varying the voltage, amperage and time with which the battery is charged and discharged, new life can be breathed into it. Lindsay goes into several methods of doing this, and in plain, simple language.

Using this book, I was able to rejuvenate three car batteries for use in a small solar charging setup. The book also told me how to determine when a lead-acid battery needs to be charged or discharged based on the output voltage, and I built a series of relays to switch between batteries based on those values. It’s a highly practical book and I recommend it if you plan on doing projects with lead-acid batteries.