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Post by bradblazer on Mar 5, 2008 1:06:15 GMT -5
Very interesting system and good tips.
I'm not sure you will realize fuel savings proportional to the RPM reduction by using taller gearing. The engine will still be producing the same horsepower just at a lower RPM. It will save some fuel and maybe some wear due to reduced friction. The torque being produced by the engine will be higher so the noise level may be a wash.
Brad
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biggkidd
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Post by biggkidd on Mar 5, 2008 9:19:14 GMT -5
Man Oh Man Super info Ron. It sure is nice of you to explain all this in terms my simple mind can understand. It sounds like some of the other guys are learning a little too. This has been such a cool project. The next thing to do is to make a bigger charger. But with all I have learned from you & the other guys it should come out better. I am still going to add one or two more alternators to this one and make sure its running in the right direction. Then I am going to reroute my batteries. I found that they will last longer and have a more equal draw if they are in groups of four. Not to mention wired a little different than I have them. This is an on going learning experience for me. I would like to keep this charger as a portable unit. When I build the other one it will be stationary. I would like to find out what type of alternators would give the best service and highest output over a long time. What ever parts I use I would like to be readily available from local sources. The stuff I built this one out of was all junk I had laying around. All the help I have gotten from you guys on this site has been exceptional. I can't thank you enough. I know I would like to hear some about building a welder out of batteries / alternators etc I bet the other guys would too. I have never seen that done. Ron & Brad, The engine has an adjustable throttle like a lawn mower. When I turn it down the noise does go way down. Far as I have been able to tell it doesn't change the charge output. When I first start it the charger is under strain (by sound) but after a little while I can cut it back. Should I let it run wide open or back it down? You can tell from sound that upon first starting the alternator is maxed out. But in say 30 min. it backs off a bit, from max charge to say 90%. KIDD
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Post by Ronmar on Mar 5, 2008 21:24:44 GMT -5
Kidd(sorry, this is a long one:)) It is kind of hard to judge by sound. You really need to know the current output from the alternators, and the alternator temperature. The load could be dropping off as a result of the batteries needs lowering as they absorb a lot of charge current quickly. As the batteries take a charge, the load from the batteries applied to the alternator drops. With less load, the voltage regulator on the alternator doesn't have to send as much current to the field winding in order to maintain it's rated output voltage of around 14.5VDC +/- .5V?. Current to the field winding is directly proportional to the alternator output, and the mechanical load the alternator applies to the engine. Do you have a way of measuring the current out of the alternator? Unfortunately most inexpensive auto amp gauges only do +/- 60A. What you really need is a 100A amp gauge for each alternator. It could also be that the 70A alternator is overloaded trying to feed that several hundred amp hour battery bank, and it is overheating(especially if it is turning backwards?). As it heats, it's output and it's load applied to the engine drops. An IR thermometer should be able to tell you the temp it is running at. Another way to tell if this is happening is to measure the voltage out of the alternator when it is charging your battery bank, and compare it to the alternators low/no load regulated set output. To find the set output, Hook up the alternator to a single 12V battery, say the fully charged battery from one of your vehicles, and start up the engine. Measure the output voltage that the alternator is producing hooked to this battery. Since the battery is full, The alternator should be delivering very little current to it, and the volt regulator will be holding the voltage at it's regulated output level, usually something around 14.5VDC. CAUTION! Never disconnect a battery/load from a running alternator. Sudden reduction of load = voltage spike which can frag the diodes or the regulator itself. When you are charging the battery bank, the voltage regulator is trying to drive the output voltage up to that rated voltage. As long as the voltage is lower than that no-load voltage, it will drive the field as hard as it can to get to that voltage, and a high current output is a result. If you check the alternator output voltage after you hear that engine load decrease, and it isn't at or near the rated voltage output, then most likely the field is getting all the current the regulator can give it, and is starting to overheat and thermally limit the output of the alternator. The voltage delivered determines how fast and which direction current will flow. If the bank voltage is 12.3V and you apply 12.3V, no current will flow. If you apply 12.7V, lets say hypothetically 50A will flow into the batteries. If you apply 14.5V, a LOT of current will try to flow. Since the batteries want more than the alternator can produce, the voltage out of the alternator won't be able to reach it's set point because the alternator cant make the current fast enough to maintain the rated voltage. If the alternator is overloaded, it's voltage will drop, and a point of equilibrium will be reached with the batteries. The alternator will deliver enough current at a particular voltage to match the batteries current demand at a particular voltage, say that 12.7V at 50A. Unfortunatly, the regulator wants to be at 14.5V, so it is feeding ALL the current it can into the field to get to this unattainable goal, and is cooking the alternator in the process. As the batteries charge at whatever rate the alternator can produce, their voltage will come up. As it does, the alternator's voltage will also come up to deliver that same 50A, or whatever it is capable of putting out, until the voltage reaches the alternators regulated output and it starts to limit the output current to keep the voltage from exceeding it's set point. Your alternator may be starting out delivering 80 or 90A, but at this rate, it is quickly overheating and it's output is falling to a level it can sustain. Overloading is hard on any alternator, even a good one and will shorten it's life. Good alternators cost good money. Leece Neville www.prestolite.com/ are reputed to be of good quality, but you will need a large one to keep from overloading it. Another option might be to install a custom regulator, that is set for a lower voltage, so the alternator is not running at it's maximum output, but is set at a voltage to deliver a current more within it's rating, like that hypothetical 12.7V and 50A. As the batteries reach that level, and start to peak, the alternator will cut back it's output to keep it at 12.7V. You then switch in another higher voltage, that again delivers a comfortable 50A. When the batteries reach this level of charge, and the alternator starts to limit the current to maintain voltage, you again up the regulator set voltage, until your optimum battery voltage is reached. This is called step charging and is used to keep a small charger power supply within current limits when charging a large bank. You are still charging at a 50A rate, but the alternator and regulator will be doing it without being overloaded. As for welding, that is easy. Put two 12V auto batteries together in series for 24V and hook up your welding cables. Negative to the ground clamp and positive to your stinger/rod holder. A pair of charged regular size auto batteries is good for about 30-45 minutes of welding. I have even seen jumper cables used as welding cables in a pinch. There are a few manufacturers that make portable MIG guns that hook to batteries placed in series. Add a 2LB spool of flux core weld wire, and you have a molten metal squirt gun that can weld anywhere you care to lug a couple of car batteries:) Northern Tool sells 2 different types. Here is a link to one of them(search their site for "mig" to find the other one). www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200305299_200305299With some voltage regulator magic, you can up the output of a 100-150A alternator to get it to 30V. Hook up welding leads and go to town. Rule of thumb for welding 1/4" plate is 1/8" rod and 100A of current... Ron
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biggkidd
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Post by biggkidd on Mar 5, 2008 21:53:06 GMT -5
Ron, Do you have a way of measuring the current out of the alternator? Unfortunately most inexpensive auto amp gauges only do +/- 60A. What you really need is a 100A amp gauge for each alternator. I do have a amp gage hooked up. Its just a cheap 60 amp. I couldn't find any higher local. I am planning on one for each alternator. It could also be that the 70A alternator is overloaded trying to feed that several hundred amp hour battery bank, and it is overheating(especially if it is turning backwards?). As it heats, it's output and it's load applied to the engine drops. An IR themermometer should be able to tell you the temp it is running at. I'm sure its maxed out when it first starts. But it never gets hot to the touch. I've worked on cars all my life and it no where near as hot as one under the hood of a car or truck. Most times it starts charging at the same voltage as the batteries and slowly works up to 14.5-14.6V. As the voltage comes up the amp draw goes down. As for welding, that is easy. Put two 12V auto batteries together in series for 24V and hook up your welding cables. Negative to the ground clamp and positive to your stinger/rod holder. A pair of charged regular size auto batteries is good for about 30-45 minutes of welding. I have even seen jumper cables used as welding cables in a pinch. There are a few manufacturers that make portable MIG guns that hook to batteries placed in series. Add a 2LB spool of flux core weld wire, and you have a molten metal squirt gun that can weld anywhere you care to lug a couple of car batteries:) Northern Tool sells 2 different types. Here is a link to one of them(search their site for "mig" to find the other one).Thats good to know. ;D I bet I use that down the road. That link is good too I might just have to get one this summer. KIDD
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Post by Ronmar on Mar 6, 2008 19:30:36 GMT -5
I'm sure its maxed out when it first starts. But it never gets hot to the touch. I've worked on cars all my life and it no where near as hot as one under the hood of a car or truck. Most times it starts charging at the same voltage as the batteries and slowly works up to 14.5-14.6V. As the voltage comes up the amp draw goes down. KIDD Well if it is approaching the rated/regulated voltage, then it sounds as if that decrease in apparent engine load is due to the battery charge peaking and the alternator cutting back the current output to maintain regulated voltage, just like it is supposed to. If you have a throttle, then you could really cut back on the engine RPM(untill you just note a decrease in charge current) and still maintain a positive current flow into the batteries at a greatly reduced engine RPM. After the work I have done building my own slow speed diesel generator this past year, I am really convinced that slow speed is the way to go for peak efficiency. It is also really cool to listen to the diesel ticking over at 650 RPM:) Ron
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biggkidd
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Post by biggkidd on Mar 6, 2008 20:58:36 GMT -5
Ron, I'm betting you have a listeroid eng.? Way cool I'd love to hear about it. I want to build one in the future. KIDD
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Post by Ronmar on Mar 6, 2008 22:07:13 GMT -5
A listeroid is exactly what I have:) It is a 6HP single cylinder with a 5KW head belt driven. At that HP, it can sustain a 3KW load 24/7, and does that for about 1/8 gallon per KW/HR. At that rate, 55 gallons of stored fuel goes a very long way. Since it is indirect injection, this can be augmented with just about any liquified hydrocarbon(used motor oil, veg oil, biodiesel, whatever). If it can be sprayed thru the injector, this thing will burn it:) It's large spinning mass and slightly oversized generator head means it can start inductive loads like a much larger generator. Very simple, very few parts, VERY easy to work on and very robust. Here is a pic of it in the "Generator Room". It is my backup generator and will keep the lights, sat tv, pellet stove, reefer and freezers runing as well as the well pump. with some carefull managment, we can run the electric range and microwave, so lights, running water, heat, food and cooking almost as normal. The cooling system uses thermosiphon to circulate the coolant(no water pump). Since my house is all electric and the hot water heater by itself at 4.5KW, is more load than the generator can handle, I have a liquid to liquid heatexchanger on mine instead of a radiator or cooling tank. this allows me to transfer all the cooling system waste heat into my domestic hot water tank. I figure if I am paying for the fuel, I might as well get everything out of it that I can:). At a max output of about 17,000 BTU per hour at full load, it takes about 1.5 hours to heat a 50 gallon tank from 60F to 120F. Pretty slow recovery, but you can do a lot with a tank full of hot water. Once the tank is fully heated, any excess heat can be dissipated into the house or outside depending on if we need it inside or not. About 12,000 BTU/HR at typical load which is as much as my pellet stove typically puts out. On the generator, about the only thing we are missing is the electric cloths dryer(about 5KW)... Here is a diagram of how it will be plummed(havn't finished the piping to the hot water tank). Ron
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biggkidd
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Post by biggkidd on Mar 6, 2008 22:23:01 GMT -5
Ron, That is awesome. Where did you get the engine from? I have been looking at them for a while now. Sooner or later one is in my cards. It sounds like you have the system pretty well worked out. Another thing I have been looking into is Modern steam engines. I might just try and build one from scratch. A low pressure unit only though. KIDD
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biggkidd
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Post by biggkidd on Mar 7, 2008 17:38:10 GMT -5
Well it doesn't look like I will get to play with my power system this weekend after all. Its been raining all day and going to continue for another 24 + hours according to the forecast. So I guess we are staying home this weekend. Bummer. If it clears off early tomorrow we may still try. I'm not sure I want to though cause we would tear the heck out of the road. I would sure love to show up and see GREEN GRASS GROWING. That would sure make my day. We planted grass just before we left last weekend. KIDD
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Post by Ronmar on Mar 7, 2008 17:49:30 GMT -5
Ron, That is awesome. Where did you get the engine from? I have been looking at them for a while now. Sooner or later one is in my cards. It sounds like you have the system pretty well worked out. Another thing I have been looking into is Modern steam engines. I might just try and build one from scratch. A low pressure unit only though. KIDD I bought mine as a short block and flywheels from a vendor in portland. I bought the cylinder head from another person in Kansas. The vendor in Portland is a good guy to deal with. I think he also sells on E-bay under the business name "Powerfull solutions" I think he sells complete kits(including cylinder heads) now. There is a lot of confusion as to how the EPA will be interpreting the teir regulations toward these small slow speed engines, so some are getting out of the import business as the fines levied will be steep if someone at the great beuracuracy that is the EPA should determine that these engines don't meet the applicable stationary engine regs(which they don't appear to). But the numbers of engines is so small, and their displacement is soo small, I don't think the EPA is looking too hard at them. There are others that are still importing them though. I went the kit route after quite a lot of reading at utterpower.com about inconsistent assembly practices in India. The kit engines have never been test run, so you have a chance to validate the assembly and fix the problem, and remove any possible casting sand from the inside of the case, before you possibly thrash the new bearing and bushing surfaces. You could probably make a real efficient battery charger with one coupled to a 3 phase generator and a rectified output and custom regulator. Basically turn it into a really large 14V alternator. All the efficiency of a AC generator and the convenience of an auto alternator. I have always liked steam engines, but before I went the route of building one, I think I might take a stab at a stirling engine as part of a focused parabolic array(recycled sattelite dish) solar generator. Ron
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red
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Post by red on Mar 7, 2008 22:46:59 GMT -5
[quote author=biggkidd board=conpro thread=1202349997 see GREEN GRASS GROWING. That would sure make my day. We planted grass just before we left last weekend. KIDD [/quote] Hey Larry- I can hear the grass growing from here! Get ready to start mowing ;D ;D -Ed
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biggkidd
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Post by biggkidd on Mar 7, 2008 22:54:09 GMT -5
Hey Ed, Best laugh I've had all night. KIDD PS Can you tell I'm clueless where it comes to all this power - - - -? I know we can cuss here but I'm trying to think clean my two year old has started coping and I have a trash mouth.
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red
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Post by red on Mar 7, 2008 23:09:43 GMT -5
Kidd- Kids are just so amazing ... It just freaks you out when they quote you two weeks or two months later and at just the approiate (spelling) time. I can't wait until you start building and it ain't even my place! BTW does Ronmar just blow you away with all this techical stuff? I use to think I knew something.. . Gotta stop hanging around here! -Ed
Ps nothing make grass grow faster than rain that is if the rain doesn't wash it away ;D
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biggkidd
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Post by biggkidd on Mar 7, 2008 23:15:36 GMT -5
Ron, You could probably make a real efficient battery charger with one coupled to a 3 phase generator and a rectified output and custom regulator. Basically turn it into a really large 14V alternator. All the efficiency of a AC generator and the convenience of an auto alternator. Where can I find out how to do this? I have a good 5KW generator head off the gen. I used the frame from. The engine threw a rod after 15 years of HARD service. Guess I got my monies worth I paid a rebuilt Holly 4 for it. ;D ;D That I did in my shop. I saw one of the open box engines on Ebay for 1300? I wonder if thats a decent price? I would rather get a complete kit though. Your help with this project has been great!!! KIDD
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Post by Ronmar on Mar 8, 2008 1:50:31 GMT -5
Here is who I got mine thru. cgi.ebay.com/6-HP-JKSON-Listeroid-Lister-diesel-engine-block-head_W0QQitemZ110229706584QQihZ001QQcategoryZ11754QQssPageNameZWDVWQQrdZ1QQcmdZViewItemThat price is a complete kit, all parts needed to complete a runable engine, and that is pretty close to what I paid for all my partsto complete my engine. The pics there are even from the kit engine article on the utterpower website. This engine also has a bronze idler gear which if setup correctly makes for a little more long lived geartrain. The beauty of the kits are that all the parts will be useable. If the engine was test run in india, it could have sand damage to the main bearings, that if not immediately replaced could damage the crank journal... I know it sounds silly to have to tear apart a new engine to inspect it, but the assembly standards in india can be pretty lax, so it is really the way to go if you want to know that the engine will last. If you can rebuild a 4 barrel, you could overhaul one of these things blindfolded. As for the generator mod, A 3 phase head would be more efficient as there would be more cyples per revolution when all the rectified DC was combined. A 2 pole single phase head at 3600 RPM has a single AC cycle per revolution(60HZ). A single revolution of a 3 phase head will have a whole cycle per revolution for each phase. An auto alternator is a 3 phase head. If you take 120VAC and run it thru a bridge rectifier, you will get 60VDC. The voltage output of the AC generator like the automotive alternator is dependent on the ammount of field current you(voltage regulator) feed it. If you only feed it enough field current to put out 29 VAC, and you rectify that, you will get 14.5VDC. In this case, you might be able to use an automotive regulator to sample that rectified DC and provide an appropriate field current to maintain a 14.5VDC output. The diode rectifer would have to be large enough to handle the large currents that the generator is capable of outputting. Since it is a single phase head, there will be a lot of ripple when you rectify the AC output. A rectifyer takes the downward humps in a sinewave and just flips them upward. Single phase rectified AC would look like this and have lots of ripple(14.5V worth). You might not want to charge batteries with this without adding some filter caps, and they would have to be big as filtration is dependent on the current provided by the supply. Properly Filtered DC would look like this, basically DC with a very little ripple. In a 3 phase head, since the cycles occur every 120 degrees they overlap considerably, there is a bunch more energy in the rectified output. When combined, the ripple is considerably less noticeable. This is basically what the output of an auto alternator looks like. All the tops of the cycles overlap so the actual ripple is pretty small so they typically don't have any filtration on their output. That is why a 3 phase head would be more efficient to convert to a charger and require fewer parts. But with filtration, a single phase generator head should work. If you can get that old generator head putting out AC again, you might be able to use an alternator voltage reg and some large diodes and large filter caps to make a DC charger out of it... Ron
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