Seems I dropped the topic of batteries into the blog (Sacrificial Anode) out of the blue. I was told by my son to ‘go back and give it some context. Then tell us what happened’. So, here:

Living off the grid means generating or harnessing your own power at the simplest definition of the term and we have done so. Our system consists of 8 solar panels on a 20 foot pole next to an even higher tower with a small wind turbine. We can, on a blustery, sunny day, generate 180 watts at 48 volts, enough to keep us ‘juiced up’ and with some to spare for charging the batteries.

That natural electricity (48 Volts DC) is channeled into a charge controller and then delivered to the house electrical closet or the batteries by way of a 100 foot cable as thick as child’s wrist. I have 12, 8-D industrial fork-lift-type batteries which together store about 600 amp hours. That power (still DC) is then ‘inverted’ to 120 volts by way of the Outback inverter (situated in the closet) and fed to the house circuits. I can also feed the house circuits by way of the genset.

The gensets (we have 3 but use only two and only then, one at a time.) not only power the house directly but also power battery chargers so that the batteries remain full. That means that we can turn on the genset only when we need to (when using a heavy load)or when the batteries need charging. Most of the time we run off the stored battery power.

We make more natural power in the summer and less in the winter.

Batteries, however, are the weak link in the system. The technology is old whereas the inverter/charger solar/turbine array is relatively modern and the gensets are technology somewhere in between.

A diesel genset kept up and maintained well would last the rest of my life for the amount we use it. So would the solar panels and the sophisticated side of the system (inverter, etc.) probably. But batteries have a very limited lifespan. Especially the cheaper and more common lead & acid types which are what we have. They die young.

I put on 8 of the 8-Ds last year and added 4 more just recently. Until last year, I was relying on 8 older 6 volt batteries that made up my second bank historically speaking. The first bank we had was 48 x two-volt batteries that were salvaged from BC Hydro after reaching the ripe old age of 15 or so years. They gave me three more years before I had to scrap them.

Some batteries will last five years of light use (car battery) and others will last twenty years of heavy use (large 2 volt batteries that each weigh over 150 pounds and cost over $500 each). I’d need 24 of those.

So the last battery blog was basically about me doing maintenance by way of upgrading the battery system. I’ll have to do it again in about seven years if I do a good job caring for them, ten years if I do a great job and as short as five years if I screw up. Screwing up is easy, especially in cold weather.

Batteries need to be cared for more in cold weather and, of course, that is when we try to go some place warm. We never take our batteries with us in the winter (together the 12 weigh 18-1900 pounds) so I have to rely on something else to keep them happy. That is why we have the relatively poor performing wind turbine. Even tho it does not make much juice, it makes enough to keep the batteries happy in the winter – whether we are here or not. So it is a critical part of the system.

The other day I was taking my eight older 6 volt batteries off-line and putting on the four new 8Ds (12 volt). Connecting batteries so that they add up to 48 volts is critical. That is what the system is designed for. So, I did. So far, nothing too scary although it is all too easy to touch battery terminal ends with a wrench when you are on your back and working under a low counter in a small space. But it went well.

The scary part for me is when I wire in the #3 bank of batteries (the 4 new ones) to banks #1 and #2 that have already been in service for the last year. When I do that, I am basically adding 200 amps to 400 amps and making a potential ‘arc-of-death’ if I do something wrong. I hate that.

So, I checked and checked and then I checked some more. Then I quit and went back at it the next day repeating the checking until I was ready to attach the final battery cable to the inverter and marry up the whole system. And I checked again. When it was time to drop the cable on the battery terminal, I was pretty confident. So, I checked again.

As I was finally getting close to the terminal with the potentially lethal connection in hand, Sal walked by and yelled ZAPP!!

It is always a funny joke. We love that one. Whenever one of us is doing electrical work and concentrating hard on NOT dying, the other waits until the moment of truth and yells ZAP!. Good fun. Hahahaha.

In a few more years she’ll be yelling ‘contact!’ instead as she applies the paddles to my stopped-still heart.