The AlternatorGenerator, First Attempt. 48V Battery Charging

you can take a 12 volt car alternator connect it up with a small gasoline engine and recharge a 12 volt battery bank and that works but what if we want to recharge something else I have a 48 volt battery bank so is it possible that I could remove the voltage regulator from this have a higher voltage run into a charge controller and then recharge a 48 volt battery bank I don't know I've never seen it done before I've never tried it we're going to try it together in this video here we go foreign hi everyone I'm David and I'm on a mission to take my house and garage off-grid I'm going to talk for the next few minutes about the theory of operation which might get a little bit boring so if you want to just skip to the build go ahead and Skip forward at this point this is a car alternator I picked this one up for 100 bucks on Craigslist oftentimes car alternators have voltage Regulators built in so they're always putting out that 14.4 volts or so which is really nice for recharging a 12 volt battery and that works great for a car and if you have a 12 volt system you can use that right out of the box in my case I have a 48 volt battery bank I'm going to try removing the voltage regulator so that I can try running this up at a higher voltage I don't know if it's going to work but if we can get it to say roughly 80 volts out of this alternator then I can send it into something like this a solar charge controller yes I happen to be using a victron one that I've had from previous projects but many voltage Regulators can work for this job it doesn't have to be blue I'm going to quickly run down my theory of operation but please forgive me if I screw something up because I'm not an electrical engineer so if you have this in a car it's connected to your 12 volt battery Bank the aluminum casing of this is grounded to the negative side of the 12 volt battery inside is a voltage regulator which I think is nothing more than a pulse width modulator so it is sending out pulses of 12 volts to the field winding which is the rotor the rotor is the part that turns it rotates it's the electromagnet depending on the duration of those pulses we're going to have a larger or smaller magnetic flux depending on how large or small that is we're inducing more or less voltage on the stator or the stationary windings which are around the outside so if you're revving this alternator really high because you're accelerating the pulses are going to be very small so that the output of this continues to be 14.4 volts but if you are sitting there at idle and the RPM is very low the revolutions per minute are very low then the duration of the pulses will be longer in duration so it continues putting out 14.4 volts now if a car typically idles at 800 RPM and if this is say a two to one ratio between the crankshaft and the pulley on the alternator then we're talking 1600 RPM so if 1600 RPM is the smallest RPM that this would ever see then that might be the pulses might be continuously on at that point and so I know that I need to rev this up higher than that this gasoline engine is a predator from Harbor Freight this is self-governed to 3600 RPM mechanically and a lot of the small engines are now potentially I might be able to get 80 volts out of this alternator if I spin it at 3600 RPM but I don't know if I can that means I could direct couple this to the output shaft of the engine now that would be great because it eliminates the belt but I don't know if 3600 RPM is going to be a high enough RPM when I was looking up the RPMs for alternators I was finding that some of them can rev all the way up to 1200 RPM so I'm going to hook this up with a pulley so that I can spin this higher so I'll try spinning it up at seven or eight thousand RPM and that should ensure that I get over 80 volts I I hope it does but I will check with a tachometer later when we're actually running and see at what RPM I need in order to actually get that 80 volts out and it should be noted that I'm going to put a constant 12 volts to the rotor to the electromagnet for the purposes of this test okay if any of that was confusing don't worry we will dive into it a lot more in the video to come with all that out of the way let's talk about the parts we're going to use well this engine is the 224 cc engine from Harbor Freight this one typically retails for 200 I was going to purchase the 212 CC slightly smaller than this but this one was on sale for 170 dollars when I walked into Harbor Freight and the 212 CC was standard price of 160 dollars so this was ten dollars more and you get more torque and slightly more horsepower but the torque curve is earlier so anyways I picked this one up instead I think it's going to work well for our project now the alternator I jumped on Facebook Marketplace and Craigslist and I searched for alternators and there were dozens available within just 40 miles from my location so there's tons of alternators out there I wanted one that looked pretty decent so I bought this for one hundred dollars it typically sells for 350 dollars and I think it's rated for 220 amps so this has a serpentine belt style pulley on it it's an eight Groove pulley but I had already purchased some parts for a different alternator that had a six Groove so I'm going to be using a six Groove pulley on the engine and a six Groove belt to drive this and over here we have a solar charge controller this is an mppt or maximum PowerPoint tracker this is a victron model it doesn't have to be blue you could purchase a different brand but I don't know what the maximum voltage that this will come out at this charge controller can take up to 250 volts coming in so that should be high enough for whatever voltage we get out of this but once we actually rev it up I'll be able to measure the open circuit voltage and make sure before connecting the solar charge controller because if this puts out say 300 volts DC then I can't use this charge controller with it I don't think we'll get that high but just in theory I took this to my local auto parts store they chucked it into a machine tested it and it passed so I know it is a working alternator so that is the basic parts that we'll be using now let's get into the alternator take it apart and try to get it ready for this build it's a AutoZone Duralast which uh you know it's a rebuilt alternator and this has a slightly different style stator that I've heard sometimes nicknamed six phase even though that's not exactly accurate here we go uh one two three four and five six wires coming up from the stator so I believe the way that this is designed it's a three-phase in y configuration but there are two windings which wind up being in parallel positive post here coming off of the positive heatsink so in this case we have three pins we've got the voltage regulator built into this box and then our brushes you can see the plastic bushings here they're trying to insulate the positive plate of the rectifier from the aluminum housing because the aluminum housing is negative the negative of the rectifier is connected directly to the aluminum housing and over here we can actually see a couple of these stator windings coming up so you can see that stator winding inside here okay let's see if we can take off the voltage regulator okay so here's our brush assembly we have two brushes in there and then they're soldered outside the voltage regulator is crimped on right here it might also be soldered but let's just cut that off go so there's our voltage regulator removed I'm not sure if that's a normal solder joint that might actually be braised to me it looks like the braised point is just the very tip so I'm going to try grinding off just the top eighth of an inch and then that might release it so I might be able to pry that open now and all of these are ground away so hopefully they'll release when I try to pull the bridge rectifier up and off so this is the positive plate going to the positive terminal but underneath it is the negative plate that the diodes are connected to foreign ER has two spots where it's screwed down one spot is to the aluminum housing so we're going to be able to keep that the other spot was on the voltage regulator which is right here but we're removing the voltage regulator so we're going to lose that so I don't know what I'll do there potentially I could JB Weld or something along those lines but we'll see how secure it is and then cross that bridge when we get to it those popped off did you see that see that there nice there we go there we are so all of them broke free and we were able to pull this uh Bridge rectifier off so each one of these circles is a diode and as you can see we have a lot of diodes here they're embedded into the aluminum plates as a heat sink the top aluminum plate turns into the conductive path for the positive post the negative is the bottom one since we have six wires coming up we should have 12 of the diodes each wire is going to need two diodes yeah one two three four five [Applause] and are there any on the back side one two three four five six that'll probably be enough the plastic also indexed into the aluminum housing I think I'm okay with that uh this is a three-phase stator but there's two sets of windings in parallel they don't get paralleled until the bridge rectifier so I have to establish which wires are going to which uh phase so we've got a clamp on there so that's part of the same phase that's part of the same phase so we have three wires that are all connected to the same phase so this is an external Bridge rectifier similar to this one it's just this one is two bridge rectifiers that are joined in parallel on the DC side now this is the housing for the brushes this is the positive side and this is the negative side now the negative side is going to go to this post down here which is negative to the entire case but the positive side is going to be free floating so I need to use a new attachment because I'm not going to use this voltage regulator anymore so I need to do something else so out of my parts bin here I pulled a couple of little pieces I'm putting these things together facing up because I don't want it to go down and short to the housing and to make sure that stays in place and doesn't fall down and short I'm going to add a little bit of Loctite and I'll put a little Captain tape on here now in order to get this in place we have to hold those brushes down so there's a little hole right here and I'm going to stick my finger in to press the brushes down against their spring and as you can see the the brushes are now pressed down let's go pull that off there we go so now we've got our positive side and our negative side negative to the case and the positive side is floating there 12 volt battery connected to the inner field coil as you can see it's sucking that in it's making an electromagnet which is going to generate the flux that we need foreign foreign we have the crimps done on the end of each wire as you can see all the ones on the pink phase I ran with red and all the ones that I marked out in yellow I ran in black wires foreign I wanted to make a base for this build so I took two scrap pieces of plywood these are half inch thick and I cut them down to 20 inches by 24 inches and then I spread some wood glue on them and glued them together you can see I'm using several screws here and I'll let this dry overnight foreign I'm setting up the circular saw to trim the edges of the base so that they are nice and flush now the town did lose grid power during this snowstorm but since I operate most of the time off grid I didn't have a problem in fact I'm running both the shop vac and the circular saw off the same phase of my Schneider inverter we've got our platform it's uh been screwed together for two days we took out the screws we put on some little rubber feet on the bottom so now we've got a nice platform to build everything out there we go so we're gonna go 10 inches off the edge I'm just Center punching it right now [Music] [Applause] well the last video that I did on a small gasoline engine the the whole Contraption kind of walked away on us with the vibration so several viewers suggested getting some kind of rubber Mount so I ordered these off Amazon and hopefully they do the trick these will go in like that I wound up drilling these a little bit larger just because I mounted the engine for the break-in cycle I did that while I was waiting on a few more parts I'll be using these nuts to hold the vibration damper down to this metal plate that means I'm going to have to recess the wood for the nut to fit so the plate will sit flush on top so in order to do that I'm going to use these fostner bits and here's a 7 8 that'll be plenty of space so here's my metal plate I don't want to bother painting it so what I typically do with bare metal is I add a little bit of oil on it this is a I don't know that type of oil I've had this can a long time foreign flange nuts with the little nylon insert to hopefully keep it from vibrating off that looks pretty straight in line with each other now we can lay it in with the nuts down in the recesses you see we have a little bit of play these are one and a quarter inch screws and the board should be one inch thick now that I doubled it up foreign I mounted this little meter up here it's both an hour meter and a tachometer so it'll measure RPMs and it just wraps around the ignition coil did that off camera but you know great it's time to work on this side of the engine now something to note this is a counterclockwise rotation engine so watch the shaft as I pull see that it's turning counterclockwise but this alternator is a clockwise rotation now it'll actually produce power in both directions but the trouble is that the fans are oriented a certain way so the fans really want to be turning clockwise to have proper cooling across the stator so we want to turn it clockwise but this is a counterclockwise shaft so we'll turn the alternator like that and now both will turn the proper way in order to get the correct distance on here of where to put the alternator I think it will get the pulley on the shaft so this is a three-quarter inch shaft on the 212 and 224 Motors uh it has a keyway so we have a Long Key that we can put in there I checked online for hours and I was unable to find a three-quarter inch with keyway Serpentine pulley I could use a v-belt like this this is a clutch with a v-belt and it fits the three quarter inch shaft and I could replace the pulley on the alternator and that's uh commonly done with a lot of projects that you'll see out there but I didn't want to do that I really wanted the high surface area of the serpentine belt so instead I found a serpentine pulley and I'll leave a link to this in the description below now this pulley is made for a power steering pump it is a six Groove serpentine belt pulley now this won't just slide on um the spec sheet says that this shaft is three quarters of an inch which is 0.750 inches the spec sheet for this pulley says 0.748 so we should have 2 000 of an interference fit between the two there we go it's not going to just press on just by hand I purchased a little tool kit for a power steering pump pulleys so I've never done one of these kits before all right so don't know which one will fit turns out I don't have the right size adapter the shaft on the engine takes a 5 16 by 24 inch thread and unfortunately that's just not in this power steering pump kit so it must not be a common size for power steering pumps looks like I'll have to make something this is a 3 8 inch Bolt now it's a piece of all thread but so I'm actually really excited about this little part uh it's fun being able to make something uh I don't have a lathe but I think it'll work off that uh drill press so let's give it a shot first time uh doing this setup so let's see here this is the adapter uh came in the that kit there we go so that is supposed to take place of this type of thing but now I have the right thread all right finally I had no idea that pulley was going to be such a pain to get on but now I've got a part to do it again if I need to so the back edge of this pulley needs to line up with this line that I drew on the ground there we are and now we'll tension it by pulling is move that over to the next hole and then that should be better be more tensioned and I'm just making this up as I go that might be too loose as well wow this is taking a lot longer than I expected if you're still sticking with me thank you so much for doing so we finally finished what I think is the mechanical side of everything and now we're going to switch gears to the electrical side so we have all of the wires coming external but now we're going to focus on those external components the full Bridge rectifier capacitor Etc the electrical side of making all these connections the stator has two windings so we have the three phase from one winding and we have the three phase from the second winding we also have this one going to the field coil which will create that electromagnet these need to connect up to something so let's look at some of the components we've got acquired first thing we're going to need is this it's a full Bridge rectifier and I got two of them because we have two stator windings so the stator windings go to this full Bridge rectifiers from there they're going to have to jump to some bus bars to combine the DC side we're going to need a capacitor to smooth out that waveform make sure that it's a nice steady DC and then I even picked up this DC to DC Buck converter which outputs 5 amps 12 volts which that will hopefully power up our field coil this is a 40 to 160 volt DC input and 12 volt output I hope we're going to fall in that range so that all this works now I don't necessarily think it's going to self-excite I kind of hope it will you know that would be awesome but I might need to jump start it with a little 12 volt battery uh and just hit it for a second get everything up and running and then the battery can go away but we'll find out together now the thing is that full Bridge rectifiers get hot so we need a heat sink and that's why they're set up on the back side for heatsink so I happen to have this big heat sink here so this little pink thing this is kind of a thermal pad to help transfer heat it's a big aluminum heat sink so I'm thinking that the bus bars and the capacitor will probably be mounted over on this side and over here I'll probably toss in the uh big heat sink and I can put something like this together Maybe so that these things can transfer to the heat sink that way this uh these wires that I already have on here they can reach so I'm going to Mark the holes [Music] again on there nice and tight this will be our DC to DC Buck converter foreign I'm going to torque that down with a socket so I'm just waiting until I have all of them on there so as you can see all the Reds coming out from the alternator are going to one of the full Bridge rectifiers the exact position on here doesn't matter so long as it's on the three-phase side over on this one you can see the three-phase side has a little sine wave little swirl mark on there and the other side is marked positive if I can get it to focus there's a little positive symbol and a negative symbol so that's the DC side so next I need to make my wires from these bus bars and they're going to travel around the side and then go up to this main positive and negative posts on both of these full Bridge rectifiers since I'm using 12 gauge for the three phase I thought it would be suitable to use eight gauge so this is eight gauge and then I'm combining it with these ring Terminals and I love these ring terminals because they're Marine tin plated and they are UL listed as well so this one is an eight gauge by number 10 hole and then these ones are a bit bigger they're eight gauge by 5 16 and all of that information gets printed on them so anything that's 10 gauge and smaller I can use a handheld ratcheting crimper like that but anything that is eight gauge and bigger so for my applications I go from 8 gauge up to 4 ought I use this hydraulic crimper over here and they have all the different sizes they have half sizes over here it's just a really nice set it's it's complete and I don't have to look for anything and then when I'm done because the die has that eight gauge printed on it it will show up on the crimp when I'm done the right size foreign I've got my two bus bars in place the wires are nicely routed around and they're running to the full bridge rectifiers I did turn this one I thought it kind of worked a little bit better and this is the supply wire of hopefully 40 to 160 volts is what this can take I hope I can hit 80 volts and then the 12 volt out to the coil well since this is an alternator it's producing alternating current so the AC comes down into the full bridge rectifiers and comes out as DC but I'm told there's a little bit of a ripple in it so in order to clean up that Ripple and really make it nice and steady of a DC direct current I picked up this capacitor as you can see I definitely should not be hitting that 450 volts DC and it's a thousand microfarad so we got to mount this about right there in between the two bus bars and then just have a little lead jumping down from both looks like we're going to need a two inch hole that off I don't know if I've ever used the two inch this is probably the first time well we have our cool hole there and I'm just doing this in case I need to remove the capacitor I don't want it to completely get destroyed so I figure a little capped on tape might help an M5 by 0.8 I made up two little wire leads and they're coming off from the studs on the bus bars uh these are 10 gauge I really don't know if it matters what gauge because the capacitor is not going to be moving a ton of current it's just leveling out what's happening so we'll get this on I found a couple of Fasteners the capacitor did not come with fasteners the capacitor has some flat spots down here on the studs next we're going to have our take off from the last two posts and it's going to go out to our charge controller but in this case I have no idea what voltage we're going to have I don't even know if this whole Contraption is going to work and I don't know what current we might be able to pull from it so how am I supposed to size a circuit breaker so I just went big with the circuit breaker this is a 125 amp circuit breaker and I'll adjust it as I need I'll adjust once I know the current and voltage that I'm working with I can purchase a better circuit breaker for this application but in the meantime this will just be an on off switch so I'm going to turn the circuit breaker like that that way when the wire comes off I can secure the wire to in a couple of spots down to the board then this will just snap on the funny thing is I'm putting in all this effort and I have no idea if the whole thing is going to work in the end trim that out a little bit hopefully it fits oh and I'm hitting this little wire there these bus bars are really cheap really inexpensive they're tin plated brass they're very thin I know that the Amazon listings sometimes have these listed as 250 amps or 300 amps which is totally bogus I wouldn't use these in over a 100 amp application they're just going to get hot and I've seen it happen I've tested them here on my workbench they they get hot so there's much better bus bars for high amperage applications please don't use these cheap bus bars on your main inverter and battery connections they come with these little plastic acorn nuts to go over the top foreign tape across the top there we go well this is my victron charge controller it's mppt or maximum PowerPoint tracking it can take in up to 250 volts and it can output up to 100 amps to the battery I added on this little DIN rail box on a previous build with a treadmill generator but in this case I'm going to remove this 16 amp circuit breaker which I don't need anymore and I'm going to run the wires directly from here to the input terminals we're going to do a test run and just see what happens with like the belt and whether or not we get any kind of voltages off of this so the circuit breaker is off there's nothing connected to the end of the power wires that exit the contraption so clearly that belt is too loose that'll need to be tightened and both AC right now both AC is just half of a bolt we just finished the first test run the good news is nothing blew up the bad news is there's definitely way too much slack in this belt I'm going to loosen that and then I can swing over to the next hole and put some more tension on this belt foreign I want to be able to measure the RPM of the alternator so this is the tachometer and we'll just take a piece of this reflective tape so now I can measure that as it spins around the belt has a lot more tension so I hope we solved that issue and we've got our little piece of reflective tape on the alternator so that we can measure the alternator's RPM the other thing that I noticed during the test run is that it would not self-excite the field so I will have to help it so right now I'm hooking up the victron charge controller to this 48 volt battery and this battery is around 30 percent state of charge this is the victron app and it's going to let us see the incoming volts and amps and the outgoing volts and amps and wattage so that's just telling us what this charge controller is doing so the charge controller is currently on it has connection to the battery but the circuit breaker on the generator is off again this circuit breaker is currently off so we're not outputting anything turn this on foreign at this point we've been running for five or ten minutes [Music] we go did you see that your lid up face people looks like they have 66 volts there's 90 volts on the DC side that's awesome this is the big truck map and I currently have it set for 15 amps okay put this on it's reading the 90 bolts that's awesome brought this voltage down and we're at 15. so what happens if we double it we go to 30 amps I'm still doing it [Music] let's see [Music] walking around here particular and everything good write it down looks like we're maxed out right now this is three days 3 300 RPM it sounds a little bit smoother I think we probably let the idle come up a little bit 400 . all right I'm gonna turn it off now so I turned this off and I want this to keep running a little bit longer to help cool off the coil wow it worked and and not just work I mean I actually think that worked pretty darn well I mean there were so many unknowns going into this project we're using a car alternator meant to recharge 12 volt batteries and we got it to charge a 48 volt battery we're powering the field with a DC to DC Buck converter I mean the concept all came together and didn't fail didn't blow up uh I think that was a pretty big success I'm excited about it uh let's talk about some takeaways what do we learn well even when I set that charge controller up to 100 amps we did not stall out the engine which tells me that we were probably taking everything the alternator had to give us which was about three kilowatts now surprisingly maybe not so surprising to some but that's about what we could get in a car that is a 215 amp rated alternator typically at 14 volts that's about three kilowatts so we're getting the same even though we're pulling a different voltage from it uh the concept of spinning the alternator at a higher RPM to get a higher voltage that concept worked I wasn't sure if we were going to get up to 80 volts or not and we got up to 90 volts um so how could we get more out of this well I'm not sure I want to maybe we're running uh the engine at its peak of fuel economy I don't know yet but if we wanted to we might be able to supply a higher voltage like 15 or 18 volts to the car alternator to excite the field that would create a larger magnetic flux and we might be able to pull more current through the stator at that point uh another takeaway would be well right now we have two full bridge rectifiers in parallel uh potentially I might be able to hook those in series and then direct drive the alternator uh directly from the shaft and that would save us a little bit off of the belt uh whatever amount we might be able we might be wasting from the belt but we got three kilowatts out to the battery and we have uh about a two percent loss in the victron charge controller uh I don't know how much loss we have in a belt but maybe 10 percent and this being a 6.6 horsepower engine we were that's I think 4.8 kilowatts uh so you know I mean that tells me that the alternator is doing at least 70 percent efficiency but we didn't stall out the engine so you know potentially the alternator might be doing slightly better than that but I have a feeling that we're probably right on the limit of what we could do out of this setup now the alternator I bought off Craigslist for 100 bucks and this was 170 but we have a lot of other things into it so I'd say we probably have four hundred dollars or so into the full build not including the charge controller so now that we actually ran it and we got some numbers I know that we certainly don't need the expensive victron charge controller I could probably do this with a lot less expensive charge controller setup given that we only have the 90 volt open circuit so you only need 100 or 150 volt charge controller but overall the whole setup worked really well let me know if you guys want me to run a fuel economy test on this setup and we'll see how many kilowatt hours we get per gallon of gasoline we burn and what did you think I mean did you think all this was going to happen because I certainly had my doubts along the way I wasn't sure if we'd get slippage on the uh pulley uh to the shaft of the engine given that it's a press fit with no keyway I wasn't sure if we'd get slip on the alternator given that I'm using a six Groove belt instead of an eight Groove belt but you know we didn't it all it all worked we still had more vibration than I would like the platform still moved around when we put it under really heavy load so if anybody has ideas on how to mount this in a better orientation to transfer less vibrations I'd love to hear those suggestions if you need to purchase any of these items I have affiliate links in the description below those don't cost you any more but they do help out the channel if you choose to use them well thank you everybody so much for watching if you enjoy the videos please like subscribe comment and share

Channel: DavidPoz

Views: 833,139

Keywords: 48V, 48, alternator, conversion, build, diy, how-to, how to, solar, off grid, off-grid, charging, battery, battery bank, eg4, lifepower4, lithium, lifepo4, 51.2v, 12v, car alternator, stator, rotor, 6-phase, 6 phase, 3-phase, home, backup, back-up, PMA, predator, 212, 224, 224cc, max, 6.6hp, 6.5hp, hp, serpentine, pulley, belt, installation, rectifier, full-bridge, bridge rectifier, parallel, victron, charge controller

Id: CL8W5hipaLM

Length: 49min 6sec (2946 seconds)

Published: Thu Mar 30 2023