BATTERY

I had to replace the battery in my car last week. It was over seven years old, which is like 114 in battery years. My (perhaps abnormal) respect and affection for this simple device drove me to extend its life well beyond its enjoyable time. Not unlike what the medical profession does to the aging American population – extending life without regard to quality. But, I digress.

The common car battery is a simple, yet still miraculous device. Lead plates, bathing in sulfuric acid allow electricity to be pushed into it or pulled out at will. Even better, you can trickle the power in and then suck it out like mad when you start the car. It requires little maintenance other than the addition of water and lasts a pretty long time, unseen and under-appreciated.

My large affection for the battery stems from my years in Mexico, where two photovoltaic (solar) panels provided the power for my house and an adjacent guest cottage. A “bank” of six car batteries absorbed the sun’s converted power during the day and released it to run fans, lights, a water pump and even radios and a blender, as needed. With the increased work load came increased maintenance. Water must be replaced daily – lost not from evaporation, but from gassing-off of hydrogen and oxygen after electrolysis during the charge cycle. A wonderful device that evolved from the submarine service – the Hydro Cap – eliminates this water loss.

More battery bits: A “12 volt” battery is really 6 cells of 2.25 volts each or 13.5 volts, when fully charged. I’m not sure why the 12 V car system became the standard or why it is called a 12V battery. Some of us older folks can remember when lots of cars used 6 volt systems. The best way to measure battery charge is to test specific gravity of the acid solution. This is made near impossible by the new “maintenance free” batteries. Most low performance is caused by sulphur getting stuck on the plates as sulfates. This problem can sometimes be remedied by charging with high (24+) volts, instead of the usual 14-16 volts. Batteries rarely explode and only under extreme rates of charge will the H + O + spark = bang happen. The media has made us fearful of this and most everything else.

The rate of charge and discharge are critical to maintaining good plate function. When done manually, it approaches an art form. But these days, computer driven charge controllers eliminate all the guesswork, both in home 12 v solar systems and cars. Many solar systems have switched to the new “gel” type batteries, which never need maintenance. They won’t discharge fast enough to be used in cars, though.

So, next time you mindlessly start your car, maybe give a nod of “Thanks” to your faithful 12VDC battery. Assuming you even know where it is.