Home Built Generator Battery Charger Using Permanent Magnet Alternator 6.5 Hp Engine

What do you think about this video?

schickmann: What did you use to create tension on the belt to keep belt tight? I can see the bracket on the lower lobe of alternator...but what is the adjustor on the upper lobe attached to?

Life is illusion: Could you please tell me what is the difference between the size of magnets in 100amp alternators and 60amps alternators? Do 100amp ones have bigger/stronger magnets or just thicker and longer wires are used for windings?

goodcat1982: homebuilt? lol please. All you've done is connected 2 pulleys from and engine and a PMA 

NathansBackwoods: Why is it geared down, to get more current you want to put an over drive from the engine to the alternator.

bigchad007: Couldn't you get an Alternator with a regulator built in?

mipmipmipmipmip: IT IS NOT VERY QUIET!!!

Szh Zoni: @dougaustintx if i want to move alternater with a 3000 rpm motor , so which motor will u suggest me,, and if i attach a gearbox then ?? please reply me,

darion gordon: U did not make that

AlternativePowerMan: Also, when working with these little engines, don't exceed the ratio number of 500. 1 HP can power 500 watts of electrical power. A lot of the retail generators seem to use this number. It seems to be a good rule of thumb.

callmeshane303: Nice set up - bit too springy and flexible for my liking - the parts have a tendency to fatigue, crack and break. I myself would be inclined to spin the alternator at it's maximum RPM, at the motors maximum RPM and set up gearing to that effect. I'd also fit in a lever with a spring to release belt tension when starting and to allow the belt and pulley system to act as the infrequently used clutch.

bartybollocks: Nice build, I am about to build something similar, had you considered using a centrifugal clutch?

Dino Pasic: use hho as power for generator, i think it can also work on hho only, but if it is used as second fuel source it is good also

Kargaroc286: it would be better to have an external regulator, so if anything fails, you don't have to replace the entire thing

Rayxl1: Mine's going OK now I've given it a 2 to 1 reduction from engine to alternator.

bodybuildingking: A battery charges more efficiently SLOWLY then it does quickly. This rule applies for every kind of battery out there.

MrLagros: Nice video! Thanks for sharing. I just built a homemade battery charger my self. I think I'm using the same engine. Check out my video for my battery charger and other solar/wind projects.

OBXSOLWIND: Nice well done!

bowtau9: Sorry i meant over 20 + amps , Can you regulate the charge to the batteries with this type of set up , without the gm type alt ? Nice set up .....

Dnuccio95ZJ: cool

bowtau9: Is that 21 v i see ? Wow.

dougaustintx: Well Nathan, as you can see , with the engine only running at 2150 rpm it was still putting out 40 amps and the battery was already fully charged, so it really could have used an even larger pulley on the alternator to slow down the charge rate.

dougaustintx: I bought the permanent magnet alternator on Ebay. Search terms: " MAX AMP PMA Permanent Magnet Alternator Generator QC12F " I don't currenty use this PMA to charge batteries as it was putting too high voltage into the batteries, even running the engine at its slowest setting and putting a 7" pulley on the alternator in an effort to reduce RPM's and voltage. I removed the PMA and installed a standard high amp GM alternator with a built-in regulator to control the voltage.

Jay Roy: nice idea :)

TheWindMillMan: love the rev counter were did you get it great kit I love back yard engineering and tinkering love the video thanks for sharing it with us andy

aaronanalog: Use an old Moped motor for better results. 2stroke 12,000 rpm and you can gear it how ever you need to. + it uses less fuel.

dougaustintx: @bigchad007 Actually, I don't think there are any PMA's with internal regulators, at least there weren't when I put this system together. The typical automobile alternator regulates output by reducing the voltage to the rotor, which reduces the magnetism acting on the field coils. In a PMA, the magnets on the rotor are always on and working at maximum.

dougaustintx: @zoni3 I don't know what kind of alternator you are planning to use, but I can tell you that most alternators will take a lot of horsepower once the load is applied. I would not go with less than a 6 hp engine. If you live near a Harbor Freight store or can mailorder one, they put their 6 hp engines on sale for about $90 fairly often. Run the engine as slowly as you can to conserve gas. I would not run a gearbox due to the complexity and lack of long-term reliability.

doctorh2005: Is this really running by itself? Is it possible to connect to a Fiat Punto car??? Please get back to me!! Thanks!

BlanchProductions: put a smaller pulley on the alternator, that will give it some boost

dougaustintx: @Redneckology Hehe... yeah it is. You have a sharp eye. I was trying to keep the base as light as possible, and the "recycled" road sign has some good back bracing built into the extrusion.

AlternativePowerMan: Hey good work keep it up. Personally I am not a fan of PMA. Typical automotive alternators use electronic regulation which works really nice in these little air-cooled engine setups. With PMA you gotta put more effort into sizing the pulleys, watching the engine RPM, connecting the alternator after you start the engine. Still, nice setup. What were you using for power load?

rts: Wow, some commenters have no clue about under/overdrive pulleys. The 12,000 RPM moped motor suggestion was funny though. Just apply the same principles of an auto transmission shifting from low to high gear (overdrive) and you'll understand. Maximum output at the lowest engine speed possible is the goal. No point in constantly over buzzing the engine unnecessarily for sustained periods, not to mention, it burns more fuel and engine longevity.

NathansBackwoods: well it makes more sense to me to make it charge as fast as you can, might as well get full use out of what you have, just my opinion.

dougaustintx: It was almost 40 amps going into a battery that was already fully charged! The problem I had was the PMA was putting out about 17 volts with no way to regulate it other than making the engine run much slower, or adding a whole bank of batteries to create a bigger load. Thanks for looking.

Håkan Andersson: ive got one of my one i bilt it my self and i have a 100 A alternator and it works great i have not put up pictures or films on it on the web

dougaustintx: If I were still using the permanent magnet alternator, I might consider a clutch to eliminate the cogging effect at startup. I switched to a regular high capacity car alternator early on. With the car alternator (non-permanent magnet) I have a way to regulate the charge going to the battery. I still feel like an over-center type of lever engagement would be better and more reliable than a centrifugal clutch.

jacktheripped: @wiredforstereo that's why you can get 85 horse power from a 250cc Rotax ;)

gaspowerrules: @dougaustintx r theese motors reliable the 6.5 from harbor freight

NiteStar131: Fantastic work, you have a great set-up and are indeed a lucky person indeed

simonspaz: It's always best to run it on part throttle, not so much tickover/idle. At idle the piston rings don't have enough compression to make a full seal and eventually this leads to glazing of the bore and that in itself gives poor compression and will mean lower output. I used to get this on old police cars when they had excessive idling. The only option was the re-hone the cylinders and put in new piston rings.

Juston Townson: I have a harbor freight engine as well with a Omar from windblue and use this to charge a large bat. Bank. When batteries are at 60 percent I don't need to worry about over voltage, but yet I am putting in the amps needed to charge the batteries. This engine as run my camper for weeks without shutting it off! I have an external tank that will go a week with it just above idle! I love this stuff. LOL. Nice work.

Brian Pena: lol i have that same mother for my go kart (from habor fraght)

tom rushmore: ive got a pma from windbluepower and use it as a bike generator spinning it with a bike and a belt and found the belt has to be tight which mine isnt that tight but yea can light lightbulbs and charge small batterys within time its just a fun project to learn about electricity

dougaustintx: @TheWindMillMan In case I didn't answer this for you before, I got the little Tiny Tach at a local lawnmower/outdoor equipment place. They usually have 2 or 3 different styles, but they are a bit pricey (around $35). I think Briggs & Stratton makes one that is cheaper. I was kind of hoping Harbor Freight would carry some small electronic tachs for about $8, but that hasn't happened yet.

Ty Matthews: You don't think putting 50 amps into a dead battery will destroy it? Batteries are not like gas tanks or water balloons... it's not a matter of "filling up" as quickly as possible. It's a chemical oxidation/reduction process with fundamental physical limits as to how fast they can be charged. Over doing it, which you clearly are attempting to do, will likely cause it to overheat dramatically. This in turn will almost assuredly result in a nasty explosion, sending acid everywhere.

dougaustintx: The idea is to have STORED energy for use when you need it. It's kind of hard to store AC, but batteries do just fine with DC.

Home built generator battery charger using Permanent Magnet Alternator 6.5 hp engine 4.7 out of 5

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