Sunday, May 4, 2014
More off Grid updates
One thing about coming home after a long absence, there's plenty of things to catch up on. The good part is catching up with friends and family. The less good part is catching up with all the little projects around the house.
Some projects were pushed back as more immediate concerns were dealt with. My last little emergency concerned the veggie van. Somehow the veggie tank refused to heat up. As I'd have to burn that expensive store bought motor fuel until it was fixed, the veggie tank became a priority. After several days of head scratching and systems checking, a tiny vacuum hose was found to be disconnected. Problem solved.
The solar electric system isn't working at 100% efficiency. It's been working somewhat, and I've had the use of a backup generator so more pressing issues got attention. You don't paint the trim on your house while the attic is on fire.
The battery bank badly needs an equalization charge. The house runs on a dozen deep discharge batteries. Over time some of the batteries get out of balance with the others. For a variety of reasons, they end up with a lower voltage than the rest of the battery bank. That really hurts the efficiency of the whole system. The charge controller shuts down too early as the high voltage batteries signal that they are full. Then the lower charge batteries suck down that surface charge, hurting the whole bank's capacity.
When I was connected to the grid, it was easy to equalize the battery bank. First the battery water would get topped off. Then the grid would be used to over charge the whole bank. Over a number of hours, the sluggish batteries caught up to the rest of the battery bank. Top off the batteries again and it's good for a number of months.
Of course, now I'm off grid so things are little more complicated. The generator I've borrowed does not top off the batteries like the grid could so equalization doesn't happen. Bummer. It is possible to do it with the solar panels and the charge controller, but it's been too cloudy too long to make that happen. One way is to test each battery until the lower voltage ones are found. Then they are put on a charger and brought up to speed one at a time.
Along with making sure the batteries are equalized, I'm going to check all the connections for corrosion and clean them up as needed. Battery maintenance might sound like a pain, but once done I can forget about it for months.
Regular readers of my blog may remember a second smaller solar electric system was set up to run all my small loads. The solar panel is just sitting out in the driveway, but it is hooked up. Now that my long ladder is unfrozen from the ice it can be mounted up high where it'll get more sun. Getting only partial sun now, the system is only getting partial use. Even so, it's nice to have. When the main system is shut down for service, the small one can still run my Internet cable modem, wifi, and Vonage phone.
Getting totally off-grid has required a number of tweaks, but it's worth it. Even having to run a generator more than I'd like, it's still been cheaper than being on the grid.