How efficient is this Army generator? MEP-831A

good morning everybody it's a nice crisp morning about 18° fah nice layer of frost and everything and I just love mornings like this it feels great we're going to try to do a fuel economy test and a cold weather start on this generator now I've never tested the fuel economy on it but it's supposed to be pretty good so we're going to find out together here we [Music] go hi everyone I'm David and I'm on a mission to take my house and garage off grid I just added diesel fuel uh this is uh straight out of the pump so this is actually got the road tax on it I really should be buying some Offroad diesel I just filled it to the point where the fuel is touching the strainer now there's a strainer in here and this strainer is actually part of the fill tube so it doesn't go into the tank the tank starts a little bit lower and so we can just barely see the diesel fuel and I'm going to show you real close what that looks like so this is the strainer on the back of the generator if we look inside you can see it's full of diesel you can see the diesel fuel is just making contact with the bottom of the strainer so what generator is this this is an mep831a it's a military generator 3 kilowatt continuous rating uh but that is military rating so that is very conservative compared to what a civilian rated generator would be and this is a very early version of an inverter generator so we have a permanent magnet alternator a PMA attached directly to the uh air cooled single cylinder Yanmar diesel engine that three-phase goes into an onboard inverter which uh converts it uh to DC and then directly back into AC we get 120 240 volt uh Pier sine wave out of this now I like this generator because it's so efficient and you actually have the option to manually start it just in case the batteries go dead but they are glitchy so a lot of people uh dislike them for that there's some uh little nuances here there's a lot of wiring and safeties built in to for oil pressure and Fuel and everything else and so if just one thing sends signal it'll shut down to protect itself I'm going to let this run for about 5 minutes after we do a cold start uh so that will skew the results just slightly but it'll be a very small percentage in the grand scheme of it because I'm going to let this run for several hours before we come back and add more diesel fuel we're going to measure how much diesel fuel we add at the end of this run uh so that we can get the fuel economy I put the generator up on some pallets along with some extra little pieces of wood here and there uh to make it level hopefully the results will be the same same before and after uh because we're I'm not going to move the generator it's going to stay right here in this position so let me go inside and I'll show you the charge verter this eg4 charge verter is going through the uh positive and negative cables into my eg4 battery bank and it's running through this victron shunt so the victron shunt is going to measure all the power flow and that shunt is connected through Bluetooth to the app and now this is the app and there's currently no uh Power flow through it so we reset the history and we're going to be able to measure how much energy we charge uh right here on the app ooh so that's uh it's very cold all right all right so this is the charge verter now the charge verter is adjustable so with the DC breaker off I'm going to adjust this and go down to current and you see where it says 100 amps right now that would overload this generator so we're going to adjust that down to 50 amps 50 amps enter so that setting of 50 amps that is out to the battery bank and it's going to be charging at about 54 volts most of the time I have it set to 57 volts as the high cut off and so that's what we're going to do for this generator so now that we warmed up a little bit we're going to turn on the circuit breaker we can see that came up so it's 9:25 in the morning so we're reading what's going into the battery right now and you can see we're at uh 2592 Watts 48.8 amps even though the charge verter down there is set to 50 amps there's just a little difference between them and we're at 53 volts right now this will come up fairly quick to 54 volts and will be a little over 2600 Watts uh probably for most of the time we can look at the history and hey all we've charged it by .1 kwatt hours or 100 wat hours so we'll come back in a few hours and see how we're doing it's the end of the day and the generator has been running all day long and it's time to find out what our fuel economy is it's 4:30 p.m. which means that this has been running just over 6 hours now the first cool thing to note is that it's been running Under full load almost 2900 WTS at the generator 2600 WTS into the battery without me adding any fuel a lot of Civilian generators if you run them at full load they might only last you 3 or 4 hours for the fuel tank that's on board so that's one of the reasons that I like the military uh generators they they have a larger fuel tank for the load that is in there you can always run them for a full shift all right so let's find out what we're doing here we're going to first look at the app on the cell phone the app is connected with Bluetooth to the victron shunt and we'll see what we're doing now and then we're going to shut off the charge verter and let everything idle for 5 minutes before shutting off the generator so here's the app and as you can see we're doing a little bit under uh 2600 watts and let's find out in the last 6 hours we have charged 18.6 kilowatt hours nice so what I'm going to do is I'm going to wait for this to flip over to 18. seven so we get a more accurate number hopefully and then we'll switch off the charge verter and what I'd like to do is I'm going to switch off the DC side but I'm going to leave it connected with the AC to the generator uh and give everything 5 minutes to cool [Music] off and we're at 18.7 so I'm going to switch this off all right we let it cool off a bit over here we'll cut that [Music] off excellent so I'm going to use this jug for measuring the diesel fuel because it has a nice spout for pouring into the generator tank and I have a LED light behind it simply so that we can see the marks nice and easily so four quarts is 1 gallon which is what I've measured to in the past we're going to 1 and 1 12 gallons now at six quarts and let's go pour it in it will probably take all of this so we're not up to the bottom of that strainer yet so we'll keep going until we are so another six quarts which means this is a total of three gallons so if I pull this out you see the diesel fuel is right there and when we drop this in it'll it covers the very bottom there you [Music] go there you go can you see that in the bottom there so we are there all right let's come in close and take a look at how much we have remaining and down here that is two quarts that's three we're a little bit higher than the halfway mark so let's call this 2.6 quarts remaining in the container so we started off with 12 quarts total minus 2.6 so we consumed 9.4 quarts or 2.35 Gall we added 18.7 KW hours into the battery uh so that gives us 7.96 KW hours per gallon so this is a more efficient generator than running my Honda uh gasoline generator I tested my uh Honda inverter generator that's the eu6500 I believe and so we ran that one at a bunch of different ratings in a previous video if you want to check that out I can leave a link for it in the description the very best number that we got out of that was 5.9 kwatt hours per gallon so we got eight on this one and 5.9 on the Honda another data point we can compare is the generator that I made in a previous video so I made an alternator generator using a Harbor Freight engine uh belt driven to a car alternator and in that one the best we could do was 4.8 kwatt hours per gallon so the Honda is certainly better than that one uh but the uh military one is better than both so how do we compare well the military generator is about 35% more efficient than the Honda generator when running through the charge verter to charge a battery uh the military one was less expensive uh I think I paid ,000 for that one at auction and then I did fix it up so I had to put some time into replacing the rubber hoses uh and things not really a lot of money into into fixing it but uh certainly some time the Honda one just worked right out of the box but I think that Honda generator retails for $5,000 so if you can find the Honda one uh for sale at a yard sale or on Marketplace or something like that uh that's probably a good deal overall uh but the military one is 35% more efficient so that's our final number um oh and we comparing the numbers to the alternator generator that I made well the alternator generator was $400 total all in uh but certainly a ton of time that one took the most time out of anything uh so the least expensive uh and the least performance but fun to do so hopefully that gives you uh a good comparison of some different options out there diesel generators are certainly more efficient uh the military one it produces more power right at the generator but remember we have to take into account the losses to charge a battery so in this case I'm using the yellow charge verter which I will leave an affiliate link for that in the description below if you'd like to help support this channel using the affiliate links when you purchase something uh really does help out the channel a lot and allows me to keep doing these videos thank you everybody so much for watching if you enjoy these videos please like subscribe comment and share that

Channel: DavidPoz

Views: 59,119

Keywords: chargeverter, 100A charger, EG4, signature solar, honda, EU6500, fuel test, fuel, diesel, gasoline, economy, power, kwh, battery charging, solar, battery, off grid, off-grid, home, mppt, re-charging, recharging, winter, generator, army, military, mep-831a, 831, yanmar, L70

Id: ZENX9BFIdu4

Length: 12min 45sec (765 seconds)

Published: Sat Jan 20 2024