Monday, October 06, 2008

What a day

What a day
I'm fascinated by this stuff...

Here's another trace, showing my battery bank voltage over time. Much more lively than the last one.

The morning starts off at a fairly low voltage, after a dead calm day and night previously, and as the wind picks up during the day, so the voltage jerks it's way upwards on wind power.

The big trough at lunchtime shows the effect on the battery of the water being heated by the central heating system.

That big drop, at about four thirty is the water pump - topping off the main engine fresh water header tank & filling the freshwater pressure tank.

The peak, starting just before five o'clock, is the effect of the main engine's 24V generator kicking in, from when I ran up the main engine.

From six or so onwards is various lights and the telly drawing power down.

What a day - windA pretty windy night helps keep the voltage over the green line. Anything over the green line is good, as the battery refresher kicks in at that point.

As a matter of interest, I've also shown a chart of the wind speeds for the same timeframe, taken from the Sotonmet website.

The clue as to the function of the red line on the monitor screen is shown in the panel on the left of the screen.

The idea is when the voltage drops below this line, the generator is automatically started & run for a time. It's set artificially high purely for testing purposes.

And yes, before you ask, there will be a 'sleep' function - so the generator does not suddenly start at an unsociable time.

So far, I've managed to show the oil light correctly, turn on the fuel pump etc. (sort of the ignition) and run the starter motor from the PC.

The problem is, I've not been able to do this properly, or in sequence, for a variety of reasons I've still to iron out.

The biggest issue, so far, is that I started the starter motor running with the PC, but then it wouldn't turn off without me pulling the wire out at the generator (after a short sprint).

I suspect I might need a tougher relay to handle the high current there before I try that again.


  1. Wow all of this is quite fascinating... but I do have to ask how are you controlling all of this from your PC?

  2. Hi Marc

    I'll post this once I now what I'm doing (don't want to appear a complete fool).

    This is a guy who's electrics know how has not really gone much further than putting plugs on domestic appliances and changing the odd battery or bulb.



  3. Tim you aren`t interested in a seafresh H204a desalinator, a friend of mine has taken one off his bopat (in good condition)240 volts 303 galls a day

  4. Hi Rob

    Thanks - if the price is really really good.

    Else it's a bit early for me to be thinking about desalinators.



  5. Hi Tim he is looking for about £900 bearing in mind that the new price is around £4000 and its in (what looks like to me) good condition so an offer would be most welcomed im sure I would think! but is it big enough? ( 300 galls a day) and it is a bit early for you I guess. money better spent on other things. Just a thought anyway, you know how it is you pass it by and all of a sudden someone wanted it :o)) take care!