Update: Well, it looks like I did more damage than I thought. The energy monitor worked for about a week. Now the numbers are all over the board. I talked with Outback about getting it repaired. They "might" be able to repair it, for 90% of the original purchase price. I've decided not to replace it with the same model. I'm not a fan of black box electronics that are not repairable. Instead, I'm going to build my own. The electronics behind are actually relatively simple, the parts are affordable, and I can build it to my own specifications. It won't integrate directly with my outback power system, but I will get over that part. More on my progress later.
Original Post:
OK, I did not actually ask for a battery monitor for Christmas, but I am really glad we finally have one. A couple of weeks ago we bought a Flexnet-DC battery monitor manufactured by Outback Power. The bulk of our energy system is made by outback, so it seemed like an appropriate brand.
Getting the monitor hooked took some work (and one rather significant mistake) but we finally have it running and collecting data. I think I have mentioned before that not having access to system performance data has been driving me nuts. This is only partly due to my own neuroses -- there are also valid reasons. First and foremost is that fact that we will likely need to replace our battery bank in the next year. The current batteries are dropping off like flies. They have been undercharged for there entire life which is a common cause of premature failure. Before we drop a few thousand dollars on new ones, I want to get a better idea exactly what we need so we don't make the same mistake again.
Hooking the monitor up turned out to be quite the challenge. The original wiring was a bit of a rat's nest, so I took the opportunity to clean everything and make sure every wire had a purpose. It was debatable on a few of them. Overall the install went well, but I did make one significant mistake. On connecting the windmill back up to the battery, I shorted the wrench across the battery leads. This seems to have rendered one of the three monitoring ports useless - a major bummer. What it means overall is that I can't monitor the wind mill and solar separately. I can live with that. I didn't cause any more damage than I think.
So what have we learned so far? Well, the windmill has been burning about as much energy as it has been creating. The problem is, it has a dump load connected to it so the batteries don't get overcharged. Well, the charge settings for the solar are high enough that they trigger the wind mills dump load even if there isn't any wind. I talked to the wind mill manufacturer about it. They recommend disconnecting the dump load, so I'm going to give that a try. The wind mill has an alternative mechanism for avoiding overcharge - it slows itself down. Between that and the fact that I have never seen the wind mill come close to over charging the batteries makes me pretty comfortable running without the dump load. The monitor has only been active for a few days. We'll see what else we learn as time goes on.
