Boat bits (Mostly techie, sorry)

So today I wondered how best to sort the problems. Firstly the air lock, I got out the manual for the water heater and after reading it, I realised it’s either plumbed in incorrectly, or I don’t understand the system very well. This has nothing to do with the air lock, and this wasn’t mentioned anyway. However after reading the engine manual, it does say to open a certain valve before filling with water to avoid air locks. Duh!! RTFM Paul. So I did that and it helped, but didn’t completely solve the problem. I ran the engine for an hour and the temperature stayed constant, so I think it’s ok. Anyway, I’m going to be replacing the hoses shortly so can go through the whole process again then.
Yesterday I traced all the wires for the solar and wind generators to make sure I understood how they are wired in. then last night I turned off the charger before bed, and just left on the equipment we would run on a normal night passage, mast head light, AIS, radio, fridge etc to see how much power we consumed. The charger said 25Ah over about 8 hours, which seems very reasonable. Once up I put the solar back on, and we were fully charged within a few hours, thats with my rubbish solar panels that only generate 200W in total, and then only in very bright sunshine. Typically they put out about 5 amps total. The big thing is the wind gen, this is wired into the main battery without any switch, or even a voltage regulator. It’s hard to know what it’s doing, it can generate up to 30A of charge at 14V, it’s basically a car alternator with windmill sails. It has been quite breezy the last few days.
I’m looking into the whole battery charging business thing, as this will be important when we head off, many cruisers spend an hour or two running the engine each day, this is a very bad idea as it costs a lot, is noisy, makes heat and doesn’t do the engine any good. The problem is that boat batteries are very complicated to charge, you have to work within very tight restraints to get the charged fully but without damaging them. Generally you spend most days discharging to 50% then recharging to 80%, however you need to get a full charge in every so often to stop them degrading. On top of that they should be equalised once in a while to stop sulphation. As I see it connecting 3 or 4 generators of power, via individual intelligent regulators that measure current flow and voltage, before determining what voltage to try to generate or current to supply, is asking for trouble. Also I have two banks of batteries, 4 for the house and 1 for cranking, both banks are never going to be in the same state.
Still I’m enjoying learning about these subjects. Ask me any question you like about lead cell construction 😉

So off to town to buy the bits I need, I was very pleased to buy a relay and associated cable from a garage on the edge of town, without speaking any Malay, and him not speaking English. img_2890

From the garage I bought a litre of acrylic paint for the boat, this should be good for 6 years apparently, the blue paint I put on the side in May has faded on the side of the boat that gets most sunshine. It wasn’t a fancy paint, but I have been assured that normal acrylic paint is by far the best to go with. Very cheap too.

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I also picked up 8 metres of radiator hose for the water heater, this should leave me with 3 metres spare I can take for a trip around the world before throwing it away. I picked up a strip of 12V LEDS that I plan to install in the cockpit so we have a bit more light for dinner, but yet to work out where or how to install them.

Finally, back to the mast problem, I mentioned how I’m putting 12V into the cable at the bottom of the mast but getting nowt out at the top, well I had an idea, if I swapped the positive/negative of the wires around at the base, and use the mast as a ground I could work out which wire had the break in. Sure enough, it was the positive wire, because by sending +12v up the old negative wire, and using the mast as the negative, I could light up the lamp. Of course I don’t think I can use the mast as a return, sending an Amp or more through the rigging might cause some corrosion. But I’m thinking I could drop a wire down to the spreader lights and use that as the negative return. It’s not often I have both lights on anyway. The cable that has failed is the expensive Ancor pre-tinned ‘Marine’ cable !

The rigging hasn’t shipped from Florida yet, so I expect we are here for another 5-7 days min. So on Thursday we’re going to leave our berth here and head to an anchorage called “The hole in the wall” for an overnighter, then onto Rebak Marina for the weekend, or longer, until the rigging arrives, when we will drop down to Telaga Marina where the rigger is based. Hopefully the rigging will be fitted in one day, and early next week we will be off to Thailand.

Paul C.

 

 

3 thoughts on “Boat bits (Mostly techie, sorry)”

  1. Wind generators; bane of my life!

    Unlike solar panels, which can be left open-circuit without any issues, wind generators need a load or they’ll spin out and launch themselves into orbit.

    Generally you’d take the 3-phase unregulated output to a controller and “dump load” inside the boat. The regulator produces the float/charge voltage and if the battery can’t take the power, it’s diverted to the dump load (usually a resistor/heater element).

    In your case, it sounds like the dump load and regulator are completely built-in. I presume it’s a three-wire connection to the battery? (-ive, +ive and v-sense)?

    I’ve seen issues when multiple systems are trying to charge the batteries. If you’re in a marina and paying for electricity, you don’t really want the solar regulator or wind regulator to back-off because the AC charger is putting power into the batteries. Likewise, if you’re in a hurry to get to full charge, you don’t really want the AC to back off while the solar panel trickles in a few milliamps.

    You probably know all this. 🙂

    1. Hi Dermot, yes it’s complicated. I haven’t had any experience with wind generators before, but I like this one, it spins fast in light winds and is practically silent, which is the main thing I had against them. It’s an Aerogen A6 capable of 30A at 45knots, but more realistically 6A at 15 knots. It has just 2 wires going straight to the battery bank, so I think I need to look at this. They suggest a switch to short it out when charging is not needed, I don’t have anything to dump the power into, and I don’t want to create anymore heat than we already have here. Of course that would be different if I bring the boat to the UK or Ireland 😉 The PO was quoted for generator and regulator, but only was billed for the generator, I can’t find any regulator, so I’m a bit confused. There must be a default regulator fitted. I also need to re-check the wiring, as I think it must be wired bypassing the shunt as it doesn’t show up on the battery monitor as supplying any current.
      I have emailed the maker to try to get more info on this. Will post updates

  2. Hi Paul, the genny will put out three phase power at voltage that’s proportional to the speed. So I’d say the regulator is built-in. The lack of a sense wire on the battery is a bit of a nuisance though. If the regulator wants to fully-charge the battery, it’ll put out 14.4 volts but there’ll be some loss in the cable due to the current (I^2 R losses). As a result, you might see a .1 or .2 volt drop between the voltage at the back of the genny and that at the battery. The Vsense wire is useful because it brings that battery voltage back to the genny without any current demand (and no loss) so the regulator can see the voltage at the battery rather than at the spades on the back of the genny.

    If there’s a built-in dump load, you should see some sort of heat sink in the case. The usual aluminium plates, which keep the dump load cool as the wind passes over it. Like the cooling fins on a motorcycle engine. There may be some just for the regulator diodes, which will be quite small. The dump load resistors will require serious heat sinks.

    Shorting it out is handy, but be careful doing that at full load/speed. I had a windmill which would take an hour or so to spin back up when the short-circuit was removed. I think something got magnetised in there, and it would need a while to recover.

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