Out With the Old! (Batteries, that is…)
by Cam Mather
Living off the grid is absolutely amazing, 364 days a year. There is simply nothing like the feeling of accomplishment and contentment running a typical North American home completely with the sun and wind. The technology of our solar panels and wind turbine still amaze me. Standing by the PV array or under the wind turbine is a deeply spiritual experience for me. I’m harnessing nature and making it work for me… keeping my food cold, washing my clothes, lighting up my house at night, all without burning coal or having the impact of so much grid-generated power. I still wonder at water coming out of my tap, pumped from deep in the ground by the power of the sun.
The one day a year that living off the grid isn’t so wonderful is when I’m doing an upgrade or installing new equipment. Don’t get me wrong – there was nothing quite like the thrill of erecting a 100 foot tower with a new wind turbine on the top. It’s just that the work to get it there was a bit overwhelming. There were lots of things to deal with, stuff to coordinate, details to remember.
Last week we upgraded our battery bank. I had someone coming to pick up the old Ni-cads that were part of the system when we bought this house 12 years ago, and I had the new lead acid batteries here ready to go. My friends Sandy and Hans and Jake were here to help with the heavy lifting.
I also installed a new MPPT charge controller and a battery monitor. The battery monitor acts like the gas gauge on your car to give us a better idea of just how much energy we have stored for cloudy periods. The old batteries were installed with bus bar with a number of inputs from the solar panels and wind turbine, and all of this wiring and equipment had to be torn down and removed before the new batteries and equipment could be installed.
I woke up early several days last week and began running through the process in my mind. Did I have all the right bits and pieces to make it work? What order should I do everything in? What was my Plan B if things didn’t work? The house would be without power for the day, so I had to make sure that the water tanks were filled, and we took everything we would need out of the fridge and freezer so that we could keep them closed while they were off for the day. Not being an expert in this area it felt like attempting to do brain surgery… without the 10 years of medical school.
Michelle commented that she had read that surgeons actually go through the same things in their heads before surgery. Imagining what the procedure would be like and visualizing each step in the process. Removing old batteries and installing new ones and various new electronic equipment isn’t brain surgery, but it might as well be for me.
As it was the work crew got here early. The old batteries, which are heavy brutes, were removed without a hitch and we got the old ones in promptly and had time for coffee and muffins before I started with hooking everything up. The only glitch occurred when the tires on the trailer being loaded with the old batteries began to lose their inflation and it took some work with jacks and a tire inflator to get them back in shape and able to handle the weight.
All in all though it was an amazing day. My theory is that the sense of accomplishment is directly proportional to the amount of stress leading up to the job. In this case there were a number of days in the week proceeding the battery exchange that I woke up at 3 am going through each and every possible scenario and thinking of a strategy to deal with it. Michelle suggests I can lean to the “negative” side in anticipating problems. I like to think of it as leaning towards the realistic side and having a “Plan B” should anything arise. And even when everything goes according to plan, there’s no downside to having been prepared.
The new batteries are amazing. They give us almost 4 days of electricity on reserve for cloudy weather. They take up a fraction of the previous monster-sized batteries, and I’ve already built some shelves for the extra space in the battery room. Now I can relax for another 364 days.