idlerboat 116 Posted August 7, 2013 Share Posted August 7, 2013 I have two 100 watt panels, and an air X. The engine has a very small 35 amp hr alternator. Small both in terms of output and physical size. I recently installed a MK70 battery monitor by mkove . It is ...gasp...Australian made ! Mine is a very early version (as far as firm ware, ((which is upgradeable)). So far it is working very well. This unit dosnt have all the systems controlling elements that some of the mega bucks ones do, but I didnt want them anyway. It does have the shunt analyser as a seperate unit with a thermometer that you install in your battery compartment. This also alows for very short "sense leads" giving greater accuracy, because the out put from the shunt analyser is only a data stream to the head unit. About $200 aus, last time I looked. There are now Chinese units at $37 aus, that a couple of boats here have now trialed. This is early days, but at the moment it seems that even though the chineese ones do "adjust on the run" they are not as accurate as the Aussie one, and have less readable parameters. As a tool, for battery and power system management, a battery monitor is brilliant . ___________________________________________ No more lies !! ------------------------------------------------------- To the subject at hand, when cruising we never have had to start the motor specialy to charge the batteries. The reality of using the motor for sections of our passages has been enough to back us up. If you are medium load, and refuse to use your motor , no matter what, then I would go to 400 watts of solar. Besides if you have the space, they are so cheap now,, why wouldnt you ? But remember....its all a waste of time if you dont have the battery capacity. I have about 460AH of AGMs for house, a further (off line) 100 AH AGM for my anchor winch, and a standard sealed lead acid Engine battery of 170 AH. __________________________________________ A word about wind gennies....first I love them, and always have starting with land bassed stuff...way to many years ago, so you wont get a subjective anwser about noise from me. To me I hear the rise and fall of the wind (did you know that rigging noise drowns out wind gennie noise above a certain speed ? ) Second some marinas make you turn them off as a condition of entry!!! Third, for the first time ever, on our last cruise, a boat owner came over and told us to turn it off at night. Aparently the noise upset her mental state and made her have bad dreams..... Fourth, even in high winds the swirling action of the wind around boats in a marina realy drops the power output. ___________________________________________ OK now for some marina bassed numbers. In the last six days. All my power, except for the heater is on 12v boat supply. I have used 252.38 amps. I have input of 122.51 amps. My net position of battey usage is 65.73% of usable AH The greatest usage is the telly !! Followed by the fridge. The sun angle is at the lowest (I cant be bothered setting up a tilting panel system) The days have been mostly overcast. Wind speeds have been stronger than most of the year. (For a few hours a day). ___________________________________________ Summary.. Dont expect real numbers when bassed in a marina. Wind gennies come into their own for passage making, especialy at night. Go for the most watts of solar panels that you can comfortably fit. Make sure your battery bank matches your expectations. Use less power. Link to post Share on other sites
idlerboat 116 Posted August 7, 2013 Share Posted August 7, 2013 While its on my mind... For smaller boat owners with say less than 20 HP engines, be very carefull about retro fitting big alternators. They do blead off a large amount of HP. If your prop size and pitch is set to get the max from your engine (good thing), then at full revs, a bigger alternator trying to recharge flat batteries may bog your engine to the point of trouble. Usualy seen by large black deposits in the water and the engine not reving up to full speed. The problem is, you will only know this if you have flattened the batteries. After that, you can only deal with it by disconnecting the alternator (which needs to be done in a certain way not to damage it) OR make sure that you have a seperate engine battery, and never draw off it..and can switch the house bats out. .......... Link to post Share on other sites
Guest Posted August 29, 2013 Share Posted August 29, 2013 Morehere http://www.cruisersforum.com/forums/f14 ... 517-2.html Link to post Share on other sites
idlerboat 116 Posted August 30, 2013 Share Posted August 30, 2013 I can roughly summarise all of that...and other sites and opinions. AIR X loud. Lower start up speed usualy means lower top end amps out. ...and mostly quieter. Higher top end amps, higher start up speed. It makes perfect sense due to internal resistance, given the = size of the blades. Smaller blade with more blades (5) usualy sames as low speed units. (But they dont make a noise like the ASIR X but they do make quite a loud noise (like wind blowing through tree branches). AIR X in a marina enviroment...forget it. On open water in 15 knots plus....brilliant. AIR breaze and the rest will generate more power in a "non sailing" situation. If you want the power for anchorages and marina use, go low start up, otherwise you may not get any ! We only use our AIR X for passage making, and particulaly at night. The opposite of solar (windy an dark) Even then, dont be fooled....there can be long pieriods of no wind and no sun...... As an edit...this whole debate realy is about finding the unit that best suits your cruising habbits. Link to post Share on other sites
Island Time 1,235 Posted August 30, 2013 Share Posted August 30, 2013 air x is no longer available, so can't enter the discussion of what to buy. the nearest equivalent is the silent wind one. IB, which blades do you have on your air x? black originals or silent wind blue ones? if it's the black ones you would notice a huge difference if you upgraded. lower startup, reaches Max output earlier, and hugely quieter... Link to post Share on other sites
idlerboat 116 Posted August 30, 2013 Share Posted August 30, 2013 Hi IT, yep, using the airx as a bench mark only....fact is all of the new machines are going for lower start up, because that is the cruising style of most boats now. (Air x is an old idea of long distance cruising from the 80s) No havent changed becaues the newer blades simply have a larger swept area.///or broader base cord. Gives them more torque, slower top end speed, and a little bit quieter. For me , I want Max power when cruising at night under sail. I want to see 15 plus amps comming in. ...and I love the noise ! There is (to others) a large range of bolt on blades for early air machines. They may solve some of your problems. Do remember that wind generation technology and power generation technology is only changing by fractions these days. ( I would love to see the next quautum leap). It is much more about what is usable wind speed for your situation...and maxing what you have to suit. Having done stand alone, remote power stuff...you can have the biggest spec machine you care to pay for.............but if you dont have the wind speed, you wont get the amps..... Whats worse, is that if it is designed for (as I have mentioned) high wind speeds...you may get diddly squat. No question...bigger blades more power......more blades...more torque....but more high speed resitance and slower speed. That why wind water pumps have heaps of blades for slow speed high torque. Electrical generators need high speed. gear boxes to take low speed high torque to high speed burn up HP. Large commercial units use this only because they cant run huge blades at high speeds. ( and a whole lot of smaller units is not cost affective) Sorry IT a ramble for others to understand why this whole wind thing is not just a case of the latest advertising. sorry ps Max output earlier, ....no they dont ! They reach lower output quicker, but not the top end output (35 amps). By virtue of their greater length they spin up slower. Greater length = slower speed. Slower speed = less amps. But they have greater torque so the friction of power generation is easier for them...to that point. Again, the reason for these blades is that for most people they just dont have high wind speed. As a further point....it is usefull to look at power to wind speed ratios. It is an upward curve, not a straight line. Again, the truth is that most boats use(expect) wind gennys to operate at a wind speed that is lower than they would even except as a solid sailing breaze. Link to post Share on other sites
Island Time 1,235 Posted August 30, 2013 Share Posted August 30, 2013 sorry IB, I don't agree. my experience is that I replaced my air breeze blades with a set of silent wind blades. they are approx the same area, but about 10mm longer (from memory, I could measure). they are a balanced set, and much smoother and better finished than the standard ones. they are also stiffer, start earlier, and achieve Max output in less wind, for whatever reason. they are also considerably quieter, a fact that we are often asked about. I think that these blades are a more efficient design, due to shape, stiffness, and finish. seems to me that the silentwind gens are now one of the few that can do 30+ amps. they are still relatively quiet, and, if/when the air breeze fails, that's what would go on next. start at a low wind speed as well as high output... Link to post Share on other sites
idlerboat 116 Posted August 31, 2013 Share Posted August 31, 2013 Hi IT, thats what it is all about, personal expirience. I have just measured a pair, up the row here, and compared them to mine, so yours must be a differant model. I would be very interested in what you have, becuase the gains thet you have mentioned are amazing given how hard it is to get efficiencies of that kind at this end of the wind genny world. I must say that balance for starters is not likely....the old air x are within a gram or so. The only possibility would be "spun balance" that is like wheel weights on a tyre. That does not work unless it is done on the actual genny (to take out very small shaft bend). Smoother ? not sure. Stiffer BAD !! The design of most modern "clever" wind genny blades is to have a carefully set degree of flex. The flex acts as a kind of "feathering" to allow the wind genny to stay at a more constant speed. Stiffer blades make the genny speed up to overspeed electrical shut down sooner. That is why stiifer blades are advertised as being better....because they do provide more power....but not in a good way. You will see that large scale wind gennies will have blade flex of up to 22 degrees. In a strong wind it is fantastic to see the curl on these things. I would consider it possible that given greater stiffness and perhaps even finish, that you may gain half an amp .....IF the blades were the same dimensions.... I dont belive that it could be anymore. As I have said.... all the after market blades that I have seen have a broader section close to the base (hub). This gives them a greater start up ability, but slows their top end speed. (and all that I have seen are longer ..by a lot more than 10 mm) Link to post Share on other sites
idlerboat 116 Posted September 1, 2013 Share Posted September 1, 2013 Further tooo I have done some more measuring. The various after market blades here range from 100mm to 150mm longer, than the original. They are not the "blue blades" that IT mentions. This is a link to what I think is the blades that he is talking about. http://www.silentwindgenerator.de/54.html It has their power curve graphs. (theres versus original) I cant find any dimensions anywhere for these blades, but if someone can , can you post it here please. The vast majority of "happy customers for after market blades, mention only noise (much quieter) but with no referance to a change in output. The fewer "unhappy customers" seem to be unhappy with the change in performance specs. BUT, first who knows what those blades are....(a few companies make after market blades) and second, I can find no referance to performance at all in after market blades except that quoted above. It is interesting that the gains on the graph are between the 7ms to 11 ms (wind speed). This may make a differance to you. That is about 13.5 to 21 knots of true clean wind. (These are wind tunnel tests) To be fair to this company a rough average of about 60 watts or 5 amps, in a perfect world............. This is not a bad gain, and should be considered. You will also see that they both start to generate at the same point. (wind speed). You could get a start up at lower wind speed, but it would by virtue have much greater drag and a lower RPM at higher wind speeds. (and that is what most of the newer generation of wind gennies do). Link to post Share on other sites
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