More Efficient than ever! Alternator Generator fine tuning, Part 3

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Күн бұрын

Can we charge a 48V off grid battery bank with a 12V car alternator and small gas engine?
Video Part 1 was building the alternator generator project: • The AlternatorGenerato...
Video Part 2 was fixing problems, answering questions, and running our first fuel economy test. We also checked for over-heating issues: • Viewer suggested upgra...
This video is part 3, and we find the sweet-spot for fuel economy.
Video, Honda EU6500 Inverter Generator: • Not what I expected.
I bought a 12V car alternator off of craigslist for $100. Next was a Predator gas engine from Harbor Freight. In this case, I purchased the 224cc MAX engine, which is 6.6hp. The 212cc 6.5hp engine would have also worked well for this build.
The goal is to make a dedicated generator that can recharge my 48V battery bank. I'm using the EG4 LiFePO4 batteries, which is a little more than 30kWh. Sometimes, during the winter, the solar production doesn't keep up with my loads. That's when I need to supplement my solar with some generator run-time in order to recharge my battery bank. Yes, 48V generators exist on the market, but they are thousands of dollars. I built this generator for about $400.
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Previous Video making a battery charging generator from a free treadmill motor: • DIY DC Generator: char...
Disclaimer:
My videos are in no way intended to be instructional "how-to" lessons. I am simply documenting my project for informational purposes. Property damage, personal injury, or death may result, even when following manufacturer's instructions. I cannot be held liable for such damage or injury. It is YOUR OBLIGATION to ensure that you are complying with any local and federal laws as well as code and permit requirements.
David Poz, LLC

Пікірлер: 331

@ThatCarGuyYT 7 ай бұрын

I came back to thank you for your video. I live in the middle of nowhere in Italy and when I saw your first video I decided I wanted to build a very similar setup just in case I needed one for my solar system. I am a mechanic and a very good fabricator but know nothing about electronics. I called a friend who is an electronic engineer to help , showed him the video and we decided to give it a try. Since I’ve access to waste oil I decided to go with a full size old diesel car engine(VW) and my friend made me go with three alternators since we have the power to pull them and basically free fuel. He made a complete system that is made to not overcharge the batteries , turn down the breaker when batteries are full and shut down the engine 5 minutes after to let the alternators cool down and a remote start system. We have been without power from the grid and basically no sun for 6 days and I’m providing electricity to 3 neighbors and thanks to your video I was able to charge my batterie efficiently and almost for free (except the electronic and beers for my friend ). So I really wanted to come back and thank you!!!

@DavidPozEnergy 7 ай бұрын

That sounds like a fantastic project. Thanks for sharing.

@johnhufnagel Жыл бұрын

If there is a part 4, hopefully it'll be changing the pulley ratios. you should be able to get data on the alternator that tells you what RPM it needs to spin to make maximum power. from there you can calculate the pulley size needed to get the engine spinning at it's peak torque.

@billmiller4800 Жыл бұрын

I was coming to comment the same thing. The efficiency nerd in me makes me wonder how far can you go? I also wonder about 2 alternators on the same engine as you had thought at the start.

@swss12 Жыл бұрын

Except the alternator isn’t the same anymore. It’s custom. So data sheet is nothing now

@WimPrest Жыл бұрын

I would be willing to bet the OP and the the two current commenters $100 USD each that David had already done a shit ton of math and research before deciding on a pulley ratio. That kind of math doesn't make for good KZfaq entertainment though, so I'm glad he left it out.

@WimPrest Жыл бұрын

That being said, if you've got compelling math to show him otherwise, I bet he'd be open to it. Saying "go figure it out" means you've already assumed he hasn't ;)

@skirnir-atf Жыл бұрын

Same idea. Engine is 6.6Hp, which usualy conected to 3.2KW alternators (chek comercial solutions, and you find correct ratio). But here we take only 2.2KW from 6.6Hp engine, what mean it`s underloaded and fuel efficency decreasing. By lowering RPM we reduce engine power and increase efficency. Unfortunatly we reduce voltage, and Victron don`t like to load alternator at low voltage. Possible we ned pulley ratio 2.6-2.8 to 1 P.S. I am using old car alternator and it self priming. Due to age, alternator steel save some magnetic force and even without priming it`s produse 2-3V at High RPM

@vincentrobinette1507 Жыл бұрын

One thing about these small engines is, is that they have fixed ignition timing. Sometimes, adjusting the RPM gets them closer to an operating point, that makes their preset ignition advance optimal. An engine is always more efficient, if the timing is correct for the RPM and load. Under light load, the engine is more efficient at lower RPM, and at full load, (wide open throttle) you want to allow higher RPM. At full load, 3,000 RPM might be the best efficiency point for this engine. (Brake Specific Fuel Consumption)

@peterfranco6610 3 ай бұрын

Brake Specific Fuel Consumption👍 This.

@ShafaqIftikhar-pw9ld 3 ай бұрын

@@peterfranco6610lol😂

@mickhelliar2502 10 ай бұрын

Love your work mate. A few things I can recommend. 1- The power supply has a little trim pot next to the output, you can turn this to increase or decrease the voltage, which can increase or decrease the output. On my similar setup I got an 18v power supply and adjusted it down, but that depends on how much you can increase your output from it. From memory, they adjust up to about 15v. My unit was a 10A 18v boost buck converter.If possible go to this way 2- with the converter, the little trim pot can be uunsoldered and you find a similar resistance panel mount type. You then install this, with converter in a box, with panel mount voltage and amp meter. The reason for doing this, is you set engine rpm, then adjust the voltage and hence current which is sent to the rotor. This way you control output from the converter going to the rotor, which means you are driving the rotor and adjust alternator output that way. That's how power stations do it

@rilufuzz Жыл бұрын

This is definitely one of my favorite projects you've done to date!

@jasonbroom7147 Жыл бұрын

This is the coolest series of videos I've seen on KZfaq. This could be turned into an excellent documentary showing people what goes into making a generator, especially one that outputs a specific voltage.

@amilcareheredia8008 Жыл бұрын

This is something I have though of before! Thanks for making it happen!

@dirtriders3615 Жыл бұрын

Awesome man been watching you for a long time. This specific idea had my attention just to not use the charger in my inverter. Great video

@ryanroberts1104 Жыл бұрын

That is definitely better fuel economy than I would have guessed. A lot of people try to do this and keep the alternator 12v with an inverter...and the efficiency is awful. It may also be increasing in efficiency as the engine breaks in - you need a good 25+ hours on it before it's fully broken in. (There should be a noticeable drop in how much metal you see in the oil around that point) The Honda test you did is surprisingly good too - inverter generators are not the most efficient when they are not running at near full load. An old style non inverter generator may produce an extra KWH!

@ShafaqIftikhar-pw9ld 3 ай бұрын

Thankyou for the update inspirational!!!!

@BenBartlow Жыл бұрын

Love your videos and projects David. This series is quite interesting. For your next project I would love to see you make some power storage devices specifically one that uses water and gravity to store electrical energy. Or something else if you have a better idea

@NoelBarlau Жыл бұрын

Great stuff, David. I really enjoyed this build series. Thanks!

@DavidPozEnergy Жыл бұрын

Your welcome. Thanks for sticking through it.

@methods-SE 11 ай бұрын

Dude! You grew a beard and long hair and now you are working on the coolest DIY generator I have ever seen! ... It goes without saying that I am going to copy you. Thanks!

@bimmers50e30 Жыл бұрын

love this follow up!

@joshanderson1019 Жыл бұрын

I love this series and I think that making the ratios 1:1 will get you the most efficiency because that is where the engine and alternator efficiency curves align the best.

@highdesertdrew1844 Жыл бұрын

In the past, most people would do a 3-4:1 alternator:engine ratio, this was mostly because if you're using a 12V configuration and depending on the internal regulator, you need to spin the alternator fast enough for a 1-wire generator to self energize, also some alternators require a certain RPM to start generating.

@mckenziekeith7434 10 ай бұрын

In my experience alternators are much more efficient at high RPMs. If anything I would try 3:1.

@teardowndan5364 9 ай бұрын

@@mckenziekeith7434 Since he is running the rotor on a DC-DC regulator and using a PPT downstream on the DC output side to step whatever comes out down to battery voltage, the rotor is likely running at a stronger field strength and drag than necessary. I wouldn't be surprised if a good chunk of the stator heating comes from unnecessary eddy current losses in the armature instead of the copper. He'd need to fix that with some form of more proper field control before raising RPMs. The alternator is putting out 4kW at 85V or so, which is less than 50Adc. That 50Adc is split between two three-phases sets, which means 25A average per set and each coil carries current about 2/3 of the time, which means about 16A per winding. The windings themselves shouldn't get warm at all under such a relatively light load.

@JeffSkymaster Жыл бұрын

Very cool David!

@Betterstartnow Жыл бұрын

Great content, really like this project!

@_Pearls4Swine 5 ай бұрын

A much bigger flywheel or weights on the current flywheel will smooth out the vibration at your 2600 rpm torque sweet spot. the momentum of energy can not be denied

@rhiantaylor3446 Жыл бұрын

Great outcome. I would be tempted to increase the rigidity of the connection betwern engine and alternator with a horizontal turnbuckle between the two.

@michaelramos3589 11 ай бұрын

Great, thoroughly enjoyed! Still would like to see a direct drive situation. I'll admit, I'm not really comfortable with electricity and don't really understand electrical part of things. Basic electrical sure, mechanical and hydraulics are my areas of expertise. But I'm learning a lot though and enjoying it! Thank you! Keep it coming!

@ThePaulv12 Жыл бұрын

I really enjoyed that. Playing around with essentially settings to get greater efficiency was very eye opening. So, the vibration aside, you should be able to run the engine at peak torque RPM and still get the full rated power by changing pulley sizes so the alternator is rotating at the speed it was in the the last episode. What I'd love to see, is what this engine could do at peak torque vs fuel consumption vs power produced. It is well established that you get the most value out of your fuel if you run near 100% charge capacity so if you can stand the vibration this could be a great fun test. IIRC, Peak torque is usually peak volumetric efficiency (VE) or the point where the ratio of energy consumed vs energy generated is the best (peak power is where the most air and fuel are consumed). Distilled down VE is just a ratio of the swept volume of the engine x the RPM to come up with an amount of air an engine should use if filled perfectly, VS what it actually uses. So hypothetically, say it should use 100CFM air @ 2400RPM but it uses 90CFM then it's VE is 90%. The losses are, air cleaner, intake manifolding, exhaust etc, etc, etc. It is possible to get over 100% VE without forced induction but I digress.

@AbAeterno827 Жыл бұрын

Regular gas generators have a 0,15-0,16 efficiency (from fuel to electricity) given 9.6 KWh/l (of chemical energy) of gasoline. Your Frankenstein reached a 0,135 efficiency with this working configuration....I guess you are reached already an incredible sweet spot. Maybe playing with a transmission ratio between the alternator pulley and the engine will give you some extra % points, but it's all about mechanics and it is usually painful XD

@KL-nj7vi Жыл бұрын

Awesome Dave! You have a bright future in industrial design and R&D if you choose. I think all you need now is a flux capacitor and Michael J. Fox.

@chrismaddox15 8 ай бұрын

Really well done video! Love your scientific analysis. Top rate. I imagine honda's design is so efficient due to its stator directly mounts under the flywheel (permanent magnets used) eliminating the electrical losses of the belt, moving mass of the rotor, and the watts used to power the rotor. Great job sir!

@DavidPozEnergy 8 ай бұрын

Yeah, Honda did a great job.

@jenaugus1982 6 ай бұрын

A rubber coupling to replace the belting and pulley.

@norsk54472 Жыл бұрын

great data points, thankx

@davidgrea Жыл бұрын

Well done great information

@timothytocock2380 8 ай бұрын

Like every one else I absolutely love this series I've not seen anything like this thanks so much I'm going to do this with a second Alternator on my van home the only thing I'm worried about is when my lithium battery is full and charging stops will it damage the Alternator.

@Jan_Seidel 9 ай бұрын

I love your video series! That is something I will take into consideration, when building my expedition mobile. I just wonder if putting 2 alternators in series wouldn't make the system a bit simpler and - more important - long lasting and efficient.

@TechOne7671 6 ай бұрын

I have watched this from the start and fair enjoyed it. If you want a higher output voltage try increasing the excitation volts. This will reduce the current and increase the output voltage but power will be the same. What you need is a AVR to control the excitation voltage, although a crude arrangement of resistor networks would do just fine for a fixed load. All the best.

@gregharris4101 5 ай бұрын

Hello David, I have enjoyed your alternator generator series. Your technical approach, and the fact that your share all your results puts you head and shoulders above most others on KZfaq. I would like to see you continue withe your research. Here are some ideas that may be worth a second look. Your alternator has a 2.1 to 1 advantage over the engine. If you run direct drive with the engine and alternator facing with a flex coupling you can eliminate any losses from the belt and the engine will only work half as hard. This would allow you to inch you RPM's up as needed to keep the voltage above the minimum. Your original target voltage was 60 volts, I think that would still be the best target. Also with the strain removed from the engine you could increase the rotor voltage up to as much as 14 volts. This would increase the output but may require a small fan to boost the heat removal from the windings. I would suggest taking it a step at a time. Start with direct drive and see where you stand. Second step, increase the RPM, etc.

@DavidPozEnergy 5 ай бұрын

Thanks for the ideas.

@scottmuench6855 Жыл бұрын

Great test setup perfect DIY project would be interested to contrast that with the EcoFlow commercially available generator?

@highdesertdrew1844 Жыл бұрын

That's awesome. Glad to see my theory proven out. I don't think it's super necessary, but I'm now wondering if efficiency could be clawed back with a different belt length and different ratios. I will get off my butt and get my Alternator Generator rebuilt and run some tests.

@chimpera1 Жыл бұрын

Hi David. Inverter generators have an internal high-voltage dc bus at something like 400vdc. Could you try connecting your charge controller to that bus to find what kind of efficiency you can get? In theory, you bypass several steps of loss.

@TaaviTuisk Жыл бұрын

Not to mention, that what usually breaks is the inverter. The rest is ok. The 3 phase generator could be connected to the rectifier giving you a 400V DC voltage.

@namechamps Жыл бұрын

@@TaaviTuisk The big challenge is a charge controller which can handle >400V.

@ewicky Жыл бұрын

@@namechamps A PV string charge controller should be able to.

@allornothing7957 8 ай бұрын

I have a 1000w inverter generator with a broken inverter.....

@multicyclist Жыл бұрын

Great work on this.👍 Car alternators efficiency goes up at lower RPMs also. Sometimes by a lot, with of course reduced output. I imagine that your efficiency gains were from both the alternator and engine running at a slower speed. Max efficiency (as well as equipment life) is the name of the game. It is a given you will lose max output but you still can achieve the same charging results by running it correspondingly longer. In the end you will still use less fuel and unit should have an increased lifeo. The one caveat is both the alternator and engine have less cooling available at lower RPMs. So once again temps should be verified to be within acceptable ranges at the lower speed.

@darrenorange2982 Жыл бұрын

It would be really cool if you could do something with the engine heat. That could easily raise this usefulness of this by a lot.

@GeraldMMonroe Жыл бұрын

Agree. Especially for this climate zone. The least sunlight (from snow, clouds, seasonal reduction) happens when he needs the most heat. So if the generator can produce power and also is water cooled by water that is used for heating this could work well. Awkward to diy such a setup but and there are major issues such as the noise and unreliability of a generator.

@Cabinlab Жыл бұрын

I live in Alaska, and added a flange and additional pipe to increase the ambient heat in my power shed in winter. Next step is to add a heat exchanger and hydronic heating so it's efficient enough to passively maintain a high enough average temp to use lithium batteries in there. What ideas do you have besides hydronic heating? Since gas generators are usually under 15% efficiency, there's definitely a lot of energy to utilize

@g-whiz286 Жыл бұрын

@@GeraldMMonroe - What you are leaning to is a cogen system and while it is probably beyond the scope of what David is trying to accomplish, a cogen project would be a great idea. I would start with a small water cooled, low RPM (1800) Diesel engine (like one of those 3 cylinder Kubotas they use in sailboats), direct driving a two pole alternator. This would provide 60Hz power when the engine is running. The hot coolant would be pumped and sent through radiator/fan units to provide heat. Even the heat from the exhaust could be captured using an air-to-air heat exchanger and use that to heat a greenhouse or barn. No reason that one couldn't add a water pump to the same engine for irrigation or pumping water up into a gravity tank. Figure out a way to use methane gas produced by humans and animals for fuel (and cooking) and you would pretty much self sufficient.

@Vigo327 Жыл бұрын

@@Cabinlab I have collected some diesel pickup EGR coolers for an experiment to heat water with generator exhaust (and air heated by the engine casing). An EGR cooler is a premade dirty exhaust gas to liquid heat exchanger and is sized to handle the entire exhaust flow of a ~200cc engine. Time will tell if i follow through..

@eDoc2020 Жыл бұрын

The easy way to do this (not sure of effectiveness though) is to point the engine and cooling system exhaust at the outdoor part of a heat pump.

@unionse7en Жыл бұрын

I'm thinking of using a water cooled engine, it's easier to put the "waste" heat from the ICE engine into the house. Probably the most effective way to increase the efficiency. (winter colorado)

@manoo422 Жыл бұрын

Its a good idea but dont cool the engine below its normal operating temp or your efficiency will take a big hit. Thats why engines have thermostats.

@andreblanchard8315 Жыл бұрын

Look into a water cooled exhaust, a rough rule of thumb for small engines is 1/3 mechanical, 1/3 heat out the cooling system and 1/3 heat out the exhaust.

@Cabinlab Жыл бұрын

On my 4kW generator, I have an EGR cooler on the exhaust. Still need to test, but there's a lot of wasted heat energy available. Even if you used a water cooled motor, you could grab more heat off the exhaust to feed into your hydronic system

@tiboreeb5360 Жыл бұрын

@@manoo422 yes, you dont run the water directly through the engine open loop. you use a closed loop via a thermostat to keep the engine at operating temperature and only drain water that is high in temperature (less volume, more temp) that way it is also better for storage as you heat the top part of your tank first and slowly move the frontier of warm and cold water from top to bottom and dont try to heat the whole volume at once. I would also suggest using a water cooled alternator and rectifier, that way you can harvest the energy losses from it as well.

@nuttyDesignAndFab 11 ай бұрын

ok so if you want MAX efficiency: #1 change the pulleys to run the alternator RPM as fast as is safe (do a calculation of what it would spin at, at redline. might be worth buying an alternator from a sports car with known high redline, I know Toyota would put nicer bearings in those for example). The higher the voltage (more importantly the lower the current) the more efficient the electrical side will be. I guess higher rotor winding voltage could help too, just be careful not to fry it. its also a bit tricky since its technically lost energy. #2 get rid of the RPM governor of the engine, as throttling causes pumping losses. use extreme caution as letting the engine rev without load will destroy it. #3 set the current high and slowly start working down. Unfortunately the peak efficiency RPM of the engine needs to be determined experimentally, but is most likely somewhere between peak torque and peak horsepower RPMs.

@tombloemker9434 Жыл бұрын

Keeping the armature voltage constant is hurting the greatest area of efficency improvement. Love to see the results with higher voltage and lower rpm.

@eDoc2020 Жыл бұрын

I think the engine should run most efficiently at 2600rpm but I'm not sure where the vibration is coming from. Maybe adding another stiffening brace running perpendicular to the existing one would help add more rigidity.

@TheMacroSlacker 11 ай бұрын

Some internal resonance issues in the design maybe.

@worldwideguitarman 11 ай бұрын

It is pretty well documented on other channels that these predator engines have poorly balanced crankshafts. An aftermarket crankshaft, connecting rod and piston would probably allow for lower rpm operation with very little vibration.

@jayreiter268 9 ай бұрын

@@TheMacroSlacker I think you are correct. 48v at 40amp is about 2.6hp. That is normal load for a 6hp IC engine to respond to step loads. At 2600 rpm that is 22 power pulses per second. Each pulse puts a shock on the drive. There is some coupling of the number of poles and rpm of the alternator that must resonate. At 4.8 kwh per gallon his cost is double CA rates. He is powering batteries so there is a 20 percent conversion loss also.

@lynnshowalter1842 5 ай бұрын

Thanks!

@DavidPozEnergy 5 ай бұрын

Thank you.

@chasmarischen4459 Жыл бұрын

Thx.

@lynnshowalter1842 5 ай бұрын

Howdy Davey. I made one of these to charge my first 12v solar system. Used an old Mopar alt. with internal 90deg cooling fins and an external, adjustable regulator. It didnt care which direction it turned. Worked great til I went to 24v. Western PA winters being what they are with almost continious cloud cover Dec. And Jan., its time to build a 24vdc. Being the tree hugger I am, I chose a diesel motor so i can fuel it with used cooking oil. No fossil fuels here! The other difference in my system is the self exciting marine alternator. I understand these alternators are more robust and built to charge deep cycle batteries. Like your genny, Ill be removing the diodes and tapping the fields directly utilizing a rectifier and capacitor to soothe out any waves. Ill be finishing off with the Victron 250/100 controller as well. The victron manages my 10kw bank very well. My batteries are happy, happy, happy! Ive been off grid since 2017. This year I started improving my rain water system and quickly descovered I need more electric to run the pumps, filtration, and UV disinfection. Haven't had a utility bill in 6 yrs, and i do all this on a small 30ft by 100ft small town lot. Best Wishes!

@DavidPozEnergy 5 ай бұрын

Sounds awesome. If you record any of your work, can you let me know where to check it out?

@curmudgeinnak 8 ай бұрын

We live remote in Alaska and would love to build a system like this for our system. We use 24v. I have a few small diesel engines that would work great for this. Down side is I am not good with these kinds of builds lol.

@GREGGRCO Жыл бұрын

What about using several no cog windblue wind mill permanent magnet generators ??

@justinjja2 Жыл бұрын

I wonder how much efficiency you could gain by correcting the power factor? By using just a rectifier and a capacitor you effectively only pull power from the alternator at the peaks of the sine wave. You should be able to improve the power factor (and reduce load on the engine) simply by adding 2 big inductors after the 2 rectifiers.

@jimmurphy5355 Жыл бұрын

Because the alternator is 3 phase, and the rectifiers are full wave, the 6 power peaks nearly overlap, and the power delivery is nearly continuous. Much better P.F. than you get with single phase.

@marklewus5468 Жыл бұрын

This project is really interesting, but you have to consider that a Honda fuel injected EU3200i plus a Victron 120VAC to 48VDC charger (96% eff.) provides 6.86KWh/gal. to the batteries at it’s rated output (~48 amp charge rate). That’s 40% more efficient than the homebrew. Yes, the Honda is a $2500 generator, not $400 in parts. But you have to consider fuel cost based on expected runtime, and reliability. Still very cool!

@DavidPozEnergy Жыл бұрын

Absolutely this is not the most efficient option out there. But it's a lot of fun. Going into this project, I wasn't sure if I could get 3kWh/gallon, let alone 4.8!

@marklewus5468 Жыл бұрын

@@DavidPozEnergy Thanks David for your reply, and for what was a very interesting video series. I really enjoy your channel.

@lonniedomnitz1720 4 ай бұрын

Wud love to see part 4 test an alternator actually wound for 48volts.

@Vigo327 Жыл бұрын

Thanks for this short and sweet video. Im surprised the middle ground was noticeably more efficient. Im not sure whether that primarily comes from the engine side or the alternator side, but it definitely has a noise level benefit. Even though im a ‘car guy’ first i tend to hate the sound of constant speed single cylinder engines droning away. Lowering RPM is the easiest way to address that, if it doesn’t cost you anything else. I once went to great effort to adapt a cable throttle and large muffler to a push mower engine so i could use it on a riding mower with a small crane mounted to the front, without it being objectionably loud. It did work but im thinking round 2 of that project will just be electric propelled instead. 🙂

@CorwinPatrick Жыл бұрын

It's entirely possible that at 2600 rpm (peak Torque) there was too much loss due to vibration. It takes energy to move that mass around. So finding a Harmonic RPM where the vibration is reduced to almost nothing serves to increase the amount being generated

@jonleiend1381 Жыл бұрын

I am sure I the 100th person to mention it but be interesting to see how much better it ran with out the belt. Just a "Jaw Coupling", Spider coupler, direct drive from the engine. I bet that is one of the reasons why the generator works better.

@Enjoymentboy Жыл бұрын

If like to see this with a 3:1 ratio on the pullies as well as with a diesel engine.

@Miata822 Жыл бұрын

Great experiment. I suspect that running the engine slowly under load will cause it to run hot, shortening its life.

@gn02020202 10 ай бұрын

This video brings up a few interesting points. Is the alternator and engine mismatched? Is the alternator too small and therefore the lower RPMs is more efficient. Does second alternator need to be placed in parallel for more efficient energy transfer?

@larryperry2094 Жыл бұрын

Cool video. Ya know you may find a cvt useful. Or maybe a variator and clutch like maybe similar to a moped? Idunno just seems like more rpm control and options for speed.

@danlydick6233 Жыл бұрын

love these videos!

@Adam-ox6zy 7 ай бұрын

Is there a way to balance that engine side pulley to run smoother at lower rpm, although maybe a bigger pulley is the way to go running the engine at lower rpm so you can run the charger at 40 amps

@davidweeks1997 10 ай бұрын

Vibrations are a matter of resonance. Sort your mount points and you can inhibit resonance.

@liam3284 Жыл бұрын

The best efficency of a gas engine is somewhere near that peak torque. A larger engine pully will help.

@Cichyoffgrid 4 ай бұрын

Hello, I did exactly what you did, today I just turned it on and the voltage was 52-53v I also connected the blue ones. but the voltage on the rotor was higher and that's probably why I couldn't load the magazine unless you have another idea what I could be doing wrong

@mikedyble3648 Жыл бұрын

Good videos, some thoughts about efficency. The temperature coefficient of copper is 0.39% per deg C, so the cooler you can run the less power will be lost in the stator windings. Could you experiment with fitting finned heat sinks to the alternator as a first test. For a given power output you want the highest voltage achievable to reduce current. The rotor is drawing a constant 60w, could you strip the alternator and replace the stator winding with rare earth magnets,. Would it be worth increasing the gear ratio to spin the alternator faster, more volts and less current,. I suspect there are quite a few small improvements that could be made. Probably a lot of trial and error to get the best combination, as there are a lot of variables.

@carlosalfaro4105 10 ай бұрын

It already works in rvs with a dc to dc charger in the loop and a battery. Dont know if you could use a smaller battery.

@nefariumxxx Жыл бұрын

Wonder if you can safely run another alternator on a longer belt and have two producing power at the same time from one engine. So, the available amps of current should double in that config(?)

@Alexander470815 Ай бұрын

To reduce the losses you might wan't to remove the MPPT Controller completely. Just go with the rectifiers to the battery and adjust the field current to get the desired charging current. This will remove one additional step of voltage converting.

@coreyellisart6877 11 ай бұрын

David quick question I read somewhere on the growatt spf 5000 that all of the battery cables to the inverters need to be the exact same length

@DavidPozEnergy 11 ай бұрын

Mine are on my setup. It's good practice so that all the inverters see the same Voltage. This only applies if the inverters are paralleled on the output.

@MarcLalondeokewy 8 ай бұрын

Could you use 3, 4 or more alternators and generate more power?

@FringanSthlm 9 ай бұрын

What about a 24V generator, would that make some sort of efficiency difference?

@idronepowerrc7332 9 ай бұрын

Hi, you can will upgrade a new alternator (B8206370B) will work?

@MultiTerpen 8 ай бұрын

Why would you not connect it in series to double to voltage to reduce the cable size?

@johnprice867 10 ай бұрын

How about if it was a straight 12 volt system and an older vertical shaft lawn mower engine?

@MultiTerpen 8 ай бұрын

Could I connect this setup directly to the grid with an solar inverter? Or do I need to have the batteries connected?

@geoffreygriffiths1487 Жыл бұрын

Thanks for this series, it has been very informative. I have started to build an off grid solution for my cabin. I have an old Honda generator that has a 12VDC battery charger built into it and I was wondering if my MPPT charge controller could be used to charge batteries from it. I am a retired electronics tech and this causes me to be much more cautious when connecting things together that were not designed to used with each other. This has answered my question, though I don't think your filter cap is enough. You are right in that the charge controller was not designed to handle a ripple current, it is also not designed to filter the high frequency noise from the diodes, and brushes. You said some comments you got suggested your 1000uf cap was not big enough they were probably thinking of the cap as a reservoir, a common way they are depicted, it is actually supposed to shunt ac current to ground when used as a filter. Not knowing what the actual frequency of the ripple current does not help, because your filter should be tuned to react to that frequency. The easiest way to deal with this is to add smaller caps to the filter. Your 1000uf cap is good at filtering low frequency ac noise but not the higher frequencies of the diodes. I have dealt with this in the past by putting .01 to .1 uf ceramic caps across each of the diodes. This was in a high voltage tube amp. It wouldn't hurt to add a 10uf Mylar cap and 500K resistor across the 1000uf cap as well. The resistor is used to bleed the caps stored energy to ground so there is no nasty surprises in the way of shocks long after the device has been turned off.

@DavidPozEnergy Жыл бұрын

Thank you for your suggestion on the Mylar cap and resistor. Can't hurt, right? So might as well do it.

@geoffreygriffiths1487 Жыл бұрын

@@DavidPozEnergy Your right, and it is cheap peace of mind. The death of digital devices is noise. I have yet to put my oscilloscope on my DC generator (it's at the cabin) but I am sure it is very noisy.

@clarencewiles963 Жыл бұрын

Thumbs up 👍

@dougyoud5944 Жыл бұрын

But the inverter gen + chargeverter is still more fuel efficient right?

@adddad9779 6 ай бұрын

Awesome!!! Given 5 kWh here from the grid is definately cheaper than a gallon of gas how would a grid tied system work? Could I pull the 4.8 kWh from the grid to charge the batteries instead?

@DavidPozEnergy 6 ай бұрын

I built this for off grid setups. Certainly, the grid electricity is cheaper than the cost to run any generator.

@kirkpoland3468 10 ай бұрын

I posted a comment in #2 video that a larger pulley on the motor would help to achieve better fuel economy.

@shedrage9636 Жыл бұрын

My thought on this experiment is: power output has two primary components, the external engine load and the internal friction in the engine that needs to be overcome. At low engine load, much of the fuel burnt, just goes to overcoming the internal friction. I would try to load the engine as heavily as I can without bogging it down. Let that governor work hard! Since you can control the amp draw from your smartphone app, keep adding load till you can add no more. Gather some datapoints at differet RPS’s, extrapolate the efficiency curve and then you can find the optimum.

@davidwperkins Жыл бұрын

My curiosity is whether running 2 or more alternators will provide more electricity. My guess is that each alternator will produce less each. But will they combine for more overall power?

@robgad2271 Жыл бұрын

Mine is about an equal engine, but a 4KW generator instead of an auto alternator. I get 120/240AC that loads up the engine if the use is more than 70%. As I only use it to charge my house inverter system also, there is hardly ever a full load requirement. But the big difference is that mine runs on HHS that is powered directly from the generator output to a 12VDC that produces 30 amps on the 12v side and only draws 2.1A on the 120v generator output, meaning I have a lot more over unity out of my self powered device. On a water electrolyte that costs only pennies per gallon of water, to create it, the hydrogen generator is fairly large with a total of 3 gallons of electrolyte and uses less than a gallon of water per day to run 24 hours per day. The generator runs a little cooler and smoother, and I operate it between 2750 and 2900 RPM. Hydrogen produces a little less horsepower so I use another trick of running the hydrogen through a large aquarium bubbler in a gallon of regular gasoline, which kicks some of the hydrocarbons off into the air stream into the dual fuel carburetor. This size engine uses a lot less water and very little gas per week, but requires oil daily and a full oil change every week. Once a month while doing an oil change take the carb apart and clean it, HHO creates a little sludge like ruining propane that tends to crystalize in the carburetor throat. I haven't bought a bottle of propane in years, I use the hydrogen for the generator, the house furnace, and even the yard BBQ grill. Though you do want to get an Hydrogen generator that separates the hydrogen and oxygen, together in the same pressure vesicle above 15 psi can spontaneously combust. Even through I have a pressure switch to 20 psi cut off on my separated combustible gases, hydrogen and gasoline hydrocarbons are a lot more flammable than anything you want to use lightly. Use them with respect and with all of the safety protocols and they are better than conventional fuels.

@coreyellisart6877 Жыл бұрын

hey David you've been a pretty big help I've messaged you a handful of times through KZfaq about the growatt SPF 5000 you definitely are a wealth of knowledge. I have three of the SPF 5000 inverters all linked together I have three battery Banks 5K each lithium 48 volt 14 s daly BMS. fully charged it's about 58 volts all the way down to 42. I've read that I have to parallel all the batteries as well as parallel all the inverters to one point. it dawned on me what if one battery pack is lower than the other voltage wise. or hypothetically should I top balance all three packs before hooking them together so they're equal voltage. thanks again

@DavidPozEnergy Жыл бұрын

Hi Jon, I'm a big fan of central bus bars. When paralleling batteries, you will want them to be within 0.10 Volt of each other. If they are different Voltages, you will find the highest battery will try to discharge into the lowest battery. Sometimes this can be hundreds of Amps. Once all the batteries are paralleled, then charge them up with a slow charge to 100%. Then you can use them like normal. In your case, you have 15kW of inverters, so you will want to use 400 Amp rated bus bars or better. And, you have 3 inverters and 3 batteries. That's 6 positions on the bus bars. Check these out: signaturesolar.com/12-stud-busbar/?ref=4_rHcgZ9x-TiF- They are a good price. By the way, this is an affiliate link, if you purchase something through the link it will help out the channel.

@coreyellisart6877 Жыл бұрын

@@DavidPozEnergy I'm assuming once they've been top balanced and all hook together technically they will discharge and charge at the same voltage assuming all three separate BMS controllers are set the same

@DavidPozEnergy Жыл бұрын

Yes, they should all move up and down together. This assumes the internal resistance is the same. Same cells, same capacity, same wiring, etc.

@stephennormyle 4 ай бұрын

David I think the pully on the engine is too big the alternators power curve is about 3200 to 4000 rpm and you have the alternator running at 6000 rpm that's way outside of the power curve just think about this .. I you drive your car / truck on the hwy at 70 your engine crankshaft rpm is about 2000 rpm and the alternators rpm is 4000 in the first, second, third test all of them had the alternator running to high an rpm in your case I'd change the pully on the engine to 1-1 ratio subsequently the engine will work 1/2 as hard to run the alternator and get way better fuel economy as well the alternator will still produce the same output.. I love this project and am working on my own as well.. keep up the good work

@DavidPozEnergy 4 ай бұрын

Thanks

@chuxxsss Жыл бұрын

Morning Dave, I love this stuff. You could GEET it ,mate. Your killing the beard to, must be the ex soldier in me understanding that one.😅

@DavidPozEnergy Жыл бұрын

Thanks. I don't know the reference to "GEET", but hopefully something good.

@chuxxsss Жыл бұрын

@@DavidPozEnergy kzfaq.info/get/bejne/qb51ZcRoyL-pnpc.html

@RA-gk5zg 10 ай бұрын

I love this video series. I am very interested in building a similar setup. I have a question, sorry if is is stupid. Can you skip using the rectifier and use the AC directly from the alternator? I don’t know what AC voltage or current comes directly from the alternator. Maybe a simple circuit could make it 220 volts. The AC would be used to power the 48 volt 100 amp charger you showed in another video.

@DavidPozEnergy 10 ай бұрын

The AC coming out is wild 3-phase. It can vary from 40V to 200V, and is probably 300-400 hertz. That huge range isn't really good for anything directly. If you want to power something directly, then the best bet is to buy a standard generator.

@MultiTerpen 8 ай бұрын

@@DavidPozEnergy Could you take the DC out and put it into an Solar inverter to power the grid directly without batteries?

@jadu79 Жыл бұрын

have you thought of trying your big generator with diesel and hooking up the rectifiers on it with 120v out on the two/three phases and doing a test with that? or do you think your MTTP is having problems

@DavidPozEnergy Жыл бұрын

I hope to do another fuel economy test on the big diesel generator going through my AC-DC charger (100A Chargeverter).

@robertchristensen7950 3 ай бұрын

I believe throwing a good sized flywheel on that would help out with kWh per gallon. It's easier to maintain the rotation of a 50-100 pound flywheel than it is to turn that alternator. And a planetary gear set on the motor could allow you to keep the roms down better.

@josse311 Жыл бұрын

Hi David, did You think to use alternator from mild hybrid? There are water cooled types and they are directly for 48V... Usually they are motor-generator, so you can start engine with them. No need to use victron, no external rectifier, ...

@DavidPozEnergy Жыл бұрын

I didn't know about them until my first video in this series when a commenter mentioned it. I think it would be fun to test if I could find one. However, I've got some other generator projects in the pipeline that I'll be working on soon.

@penncapt 7 ай бұрын

Where can I get one of these from a mild hybrid? What do I search for?

@SetchiPaunda Жыл бұрын

Cool. Maybe try a hair pin winding alternator. One like JS alternators sells. Maybe a higher output efficient alternator at lower RPMs. Maybe. Just a thought

@DavidPozEnergy Жыл бұрын

I think this alternator is a hairpin style. In my previous video I show the alternator close-up. kzfaq.info/get/bejne/ebJoipiZztbFfIE.html

@rronmar 8 ай бұрын

And you have re-affirmed the issue with automotive alternators. They were designed for size and not efficiency. As you discovered They reach peak efficiency below 50% load. They do become more efficient when you increase their voltage output. I participated with a similar project a long time ago with a micro-cogen group I was a part of, and we were able to make it fairly efficient, closing in on 1/8 gallon per KWH, but that was in diesel. You will always need about 15% more gas than diesel but should be able to close in on that same efficiency for the same amount of BTU input with properly matched components. When you determined that you were overloaded thru alternator heat output and lowered the load, your chosen engine immediately became grossly oversized for the task(inefficient). The engine will be at peak efficiency at its peak torque RPM with throttle wide open. Peak torque is lower than peak HPRPM… Closed throttle = increased pumping losses. Lowering the engine RPM reduced pumping loss so increased efficiency but lower alt RPM = lower output watts. You could up gear to run the engine at lower RPM with wider throttle but you are still moving 6.6HP worth of air and parts to make 2.5hp worth of output which = inefficient. ~2HP per electrical KW output is a good rule of thumb. You see this throughout the gen industry, a 5kw gen has a 10hp engine. you saw that in your first vid when you went over 3KW, the engine ran out of HP. You want to size the engine to deliver peak torque with the alt just under 50% load(in watts). You also don’t need to run the voltage that high. You are not gaining much over 50VDC. A simple auto regulator uses a zener diode and transistor to regulate the field current. If you regulate that alt to ~50V there is no need to extensively modify the alt and add the external rectifiers and all that other wiring, and you can stick to the air-cooled rectifier on the alt. The problem we ran into was with the alt and engine matched properly, the alt could easily overload the engine as it was only at 1/2 electrical load. We were working on a load limiting reg. We didnt have as extensive a selection of dc-dc charge controllers as are available now, which solves the issue. As you demonstrated the charge controller controls the alt peak load nicely. So engine sized to 2hp per 50% of the full alt KW output, simple field regulator to maintain 50V DC output, DC-DC charge controller set to just under 50% alt output in watts, done…

@whatthefunction9140 Жыл бұрын

Love your look these days. From Mr clean to junior administrative assistant to the office of Jesus

@stubby7934 4 ай бұрын

Might I suggest a Hyundai altermotor from a 2010's Sonata? 95% efficient, should handle 50a continuous at any voltage up to 270v. Dirt cheap if you look around.

@Harbie 5 ай бұрын

I just calculated the kWh price if you would be in The Netherlands... About $2,00 per kWh.. That is really expensive if you compare it to grid electricity, especially if you consider we have negative prices (in a dynamic prices contract, some hours of the day) if the sun is shining and/or the wind is blowing a lot.

@jimdouglasgregory 7 ай бұрын

Could you set up the added to a golf cart to make a gas over electric hybrid cart

@DavidPozEnergy 7 ай бұрын

Sure, but it wouldn't be my first choice. Check out this video to see a solar option: kzfaq.info/get/bejne/gNRxZ7Vi3dunmIk.htmlsi=-cnSc52l3wvmeRH1

@ferchi_creations 4 ай бұрын

Why not more voltaje to the magnet coils?

@etusuku8848 6 ай бұрын

Hi, I made a couple of rough calculations. Your efficiency is not far of what can be gotten when you charge batteries with a Honda 1000W or 2000W generator and a good battery charger. That's pretty good, and much cheaper too. :)

@DavidPozEnergy 6 ай бұрын

Thank you.

@hondabuilder11 Жыл бұрын

What is the model number on the alternator

@billmonday5623 Жыл бұрын

As always you are the great experimenter! I still think you need to use the waste heat off the engine to make it pay off. Micro co-gen. How about a slow speed listeroid engine? There are forums for both. I have a new 6-1 Metro and a 3kw ST gen. I never got to the project. I'd sell you for a fair price. It would be good to see a video of you putting it to work.

@DavidPozEnergy Жыл бұрын

Oh, man... My wife wouldn't be too happy if I brought home another project. But, I'd love to see it. Are you in New-England? If I remember right, those were pretty popular in Maine.

@billmonday5623 Жыл бұрын

@@DavidPozEnergy CT Shoreline area. Your wife seems cool with your projects! If you want something cheep to try CO-Gen I also have a Honda 6.5 water cooled RV generator.

@juststeve7665 Жыл бұрын

did I miss where you posted the part/model number of the alternator here?

@DavidPozEnergy Жыл бұрын

Part 1 video: kzfaq.info/get/bejne/ebJoipiZztbFfIE.html At time 5:25 in that video.

@AnthonyBove Жыл бұрын

From the people that brough you Carpenter Jesus, get ready for Electrician Jesus!

@reasonablebeing5392 Жыл бұрын

I was thinking it but you commented. Uncanny resemblance to the artist representations.

@kesslerrb Жыл бұрын

I mean, it’s just hair and it’s his channel but I’ve been watching since he was buzz-cut, clean-shaven David and have always wondered why he made so dramatic a change 🤷‍♂️

@DavidPozEnergy Жыл бұрын

To answer why I'm letting my hair grow... I'm out of the Army. After having short hair my whole life, I just want to see what it's like having long hair. I started growing it out when I did a long-distance hike last year and just haven't cut it. I might grow it out until I can donate it to Locks of Love. Not sure yet.

@AnthonyBove Жыл бұрын

@@DavidPozEnergy just a playful jab, keep up the great work on the channel!

@powerprepper Жыл бұрын

@DavidPozEnergy Thank you for your service, David. Long or short hair, your content is second to none! Keep up the great work.

@wizbo27 9 ай бұрын

What if you got a buck converter with a higher output to excite the field a bit more, maybe there is more to squeeze there?

@DavidPozEnergy 9 ай бұрын

Maybe there is a little more to gain. I was worried about over-heating the field, so I kept it to 5A, 12V.

@rogerhewett2539 5 ай бұрын

Hi I use a 2008 Prius with a 9000w inverter and 4x95ahr 12v batteries wired on the 12v side of the car as my generator. Do you think it’s possible to run the 208v hv side into 1 leg of a 15kw three phase solar inverter? The same way you did with the alternator?

@DavidPozEnergy 5 ай бұрын

I've seen a video on YT of someone who did that, but I don't remember the name or specifics. I've never tried it so I can't help with details.