Using an old Light Tower to Charge Off Grid Batteries

[@junkerzn7312]

I love the generator tests. If you don't have it yet, get a hydraulic knockout punch kit for making holes in boxes. Ok, overkill for plastic boxes but awesome for steel boxes. Though perhaps not entirely applicable to this project given the size of the holes (punch kits usually go up to 2 inches or so). Still, really nice to have. Once wires get too big for wire nuts or WAGOs, there are insulated wire connectors... single side entry terminal blocks and multi-tap insulated wire connectors that work really well for unsecured cabling in relatively small boxes. I also like to use medium-sized powerpole connectors for simple splices of large wires (those are a bit more involved but you get a really solid connection and can be disconnected). -Matt

[@DavidPozEnergy]

Thank you Matt. I do own a hydraulic knockout kit. I used it in my Discover Battery video. It didn't occur to me to use it here. Maybe because the drill bit is so fast in plastic.

[@honeybadger6127]

I never heard the term "chargeverter" before, thanks for that. I've used those cheap meters before, they are perfect when you don't want to hastle with a bluetooth, wifi, network connection just to see how much power/energy has pass through it.

[@mahalkasi]

Love these tests. Hope you do a dc generator someday.

[@BadHaddy]

DC generators are specialty, wildly expensive, and need a complex management system to work with lifepo4. They really need integration with a BMS. I used to run a company that built them for telco and military customers. There's a 5-8% efficiency increase, which is worth it when you're paying VERY high prices for fuel. (Military fuel costs are 5-10x the cost for consumer.) For most consumers, the gains are not worth the financial cost and limitations (limited maintenance providers, replacement options, etc.)

[@jamesray9009]

I love how you managed to get the fuel lines off the tank with out breaking them I was trying to change the fuel pump on my mower , I broke the 1/4 barb from the pump off in the fuel line both to the carb and the fuel tank.. fished the barb out going the carb. replaced the other side cause I then broke an end off the fuel filter , then trying to fix that I broke the shut off valve.. I gave up then haha

[@antibrevity]

Thank you. I wish that you'd included some of your other results in a table or something at the end so that we could have some comparison to your other tests. You refer to the other test with the Kubota, but only those who have already watched that video might remember what those results were.

[@DavidPozEnergy]

I show the results of the old test in the video at two locations. Once at 01:42 and again at 15:29

[@ai4px]

I swear when I saw the headline I thought your were gunna shine the tower lights onto the solar panels. hahahaha

[@DavidPozEnergy]

Haha

[@ravelkoff3549]

me too :D

[@ai4px]

@@DavidPozEnergy Maybe you should do that to test the efficiency.... in the first part of april. Something like 'how to make solar panels work at night". Great click bait stuff on that special day in april.

[@DavidPozEnergy]

LOL

[@ameoba32]

Make sense. I guess generator price is a significant part in generated electricity price. So using these second hand generators, bought cheap, takes price down. Thank you for providing this data, because it looks that kwh/gallon performance fluctuates quite a lot in different generators.

[@stevedutcher3875]

Nice test!

[@WisconsinWanderer]

Thank you David always appreciate your help my best to you and family 😊

[@offgridinthepacificnorthwe3210]

No doubt the Cap based regulation is an issue. Converting that gen head to an AVR is problematic. I am sure that you can find a AVR type head that will fit the engine. I have found that a PFC "Power Factor Corrected" Head is much mor efficient. Having a PFC head that meets your minimum Peak to Peak voltage will increase your efficiency. This is something that a cap based head can not do. I am sure you know all of this. I appreciate all your effort doing these tests. 1.5 hours per gallon @ 7.7 Kwh is good. This shows great potential for the engine. With the right Generator Head I think you have a winner.

[@DavidPozEnergy]

I have not heard of a PFC head. I'll have to do some searching for information on it. As-is, I still prefer to run this than my little home-made rig. LOL.

[@offgridinthepacificnorthwe3210]

My next test is a MEP-025A I bought an NOS for $200

[@arnecarlsson9740]

8 kWh at 15 cents (our rate) each equals $1.20. Diesel is $3.00 here. Power generating companies are doing a great job!

[@BadHaddy]

That is not unexpected. Power plants live and die on 10ths of a percent of efficiency gain. David's setup here is about 18% efficient converting fuel into power. The rest of that energy is made into noise, and heat. (This is why using a generator to run an electric heater is way, way, way less efficient than just burning that fuel in a heater.) Oil fired plants in the US are 29% efficient, per the EIA. Coal plants are 32% efficient, and natural gas plants (combined cycle systems) are way high, at 44%. But this has always been the case. In 1949, power plants in the US averaged 22% efficient, vs today's average of 39%.

[@lloydbrown3825]

I'd be interested in the efficiency of dual-fuel generators running on propane. Of course, you'd have to find some other unit than gallons to compare, given the relative potential energy of propane vs gasoline (and I assume diesel). Maybe $/kwh? I know you have to use generators reasonably frequently. But for someone who is grid-connected, and only needs to use a generator for very infrequent power outages, there's a significant advantage to using propane, namely that it doesn't degrade in storage.

[@WiSeNhEiMeR-1369]

HOWdy D-P, ... Thanks for the INFORMATION COOP the WiSeNhEiMeR from Richmond, INDIANA ...

[@o.martinez4143]

Nice video

[@offgridwanabe]

Nice experiment your fun is work for me lol.

[@meganwinters5163]

Hahaha 😂👍 agreed 💯

[@andrewt9204]

I wonder if that power head can be rewired for 240. Sometimes the winding connections just need to be reconfigured as they're paralleling 2x 120V windings. Not always of course, and I'm assuming you looked at that already.

[@DavidPozEnergy]

I read the manual for this light tower and there was no mention of being able to do that. It's still a possibility, but without seeing a diagram for it, I was worried I'd burn up the stator.

[@BobHannent]

I was confused as to if this was a rerelease of the previous light tower video!

[@DavidPozEnergy]

Nope, a different one.

[@jws3925]

I must have missed when and where you sourced the diesel generator. I take it that it is not an inverter generator, correct? Does it create any "problems" with the charge/inverters? Where did you get the generator?

[@DavidPozEnergy]

I went to Facebook Marketplace and did a search for "Light Tower" in my area. Most are around $4,000 working. I paid $1,000 for mine because it wasn't producing power and the lights were banged up (broken). They are not inverter generators. If I hooked this directly to my inverters, then it probably wouldn't work. The Voltage can fluctuate a lot on these units and that would probably put my inverters into fault mode. So, instead, I use the charger. I charge the 48V battery bank with the generator and this has no problems with the inverter.

[@allstarnb1]

I’m curious, have you opened the generator head? I bet there are two windings in there wired in parallel. These can probably be separated to get your 240v. I didn’t get a good look under the control panel, but those two legs might be wired in there in parallel.

[@DavidPozEnergy]

You are correct, that the two windings are in parallel. Literally, there are two wires under one screw on the terminal block, and another two wires under a second screw on the terminal block. I wanted to re-wire it as a 240V head before the test. However, the manual for this light tower makes no mention of being able to do it. Without a manual, I was worried of burning up the stator. So I made do with the 120V.

[@allstarnb1]

@ Ah ok. If a generator like this can be had for cheap, this is the perfect setup! Dirty cheap power but the chargeverter doesn’t care. Great video!

[@zapcjw]

i would think a large 48vDC forklift motor replacinge one of those heads could make a good system im looking at twinning 2 of the 28-29v DC military generators to make a 48v capable charging system mimicking a large solar bank

[@DavidPozEnergy]

That sounds like a cool project. Please let me know if you build it.

[@bobjarrard]

David, a quick question as to deep cavity double wall insulation. Do you think that rockwool would function as well as the cellulose that you used for your home, especially as to no condensation on the back of the outside sheathing (plywood in your case with Ice and Water Shield on the outside of that)? Thanks, I try to watch all you posts twice so I don't miss anything. Bob Jarrard in Nevada

[@DavidPozEnergy]

No. Rockwool and fiberglass are both Hydrophobic. Cellulose isn't. Cellulose has the ability to absorb and release moisture just like the wood framing and wood sheathing. Also, when cellulose is dense-packed, it stops convection currents inside of the wall cavity, which means less moisture being delivered to the condensing surface (sheathing). If you want to fill a cavity with rockwool, then I'd look at the "smart vapor barriers" for the inside surface. But, remember, when installing these on the inside surface they need to be installed as an air-barrier. This means extreme levels of detail around every electrical box, window framing, interior joists and wall intersections, etc. In my opinion, not worth it.

[@bobjarrard]

@@DavidPozEnergy Thanks David, no one else has made all this clear - as you mention "Too many letters after their names!". Bob

[@DavidPozEnergy]

Your welcome. Insulation is my true joy.

[@keithbarron3654]

Snow on solar panels, could you put ultrasonic cells or rotary vibrator that could be remotely activated to allow snow to fall off cells.

[@markusviel6440]

Do you think a DC Generator would have different Effizientcy and you could use the PV Infrastructure as a Virtual "PV-Array"

[@DavidPozEnergy]

In theory, a DC generator could be more efficient. However, the components are not as common and thus, more expensive. I have built two small generators in the past as DC battery chargers only, and both were less efficient overall. But, I'm still testing some different ideas.

[@trygvetveit4747]

Tip: I got 6 pcs. IBC touts in my garage under my house as a Heat storage, guess you got a large tank innside your house aswell? I use a Yanmar genset also , BUT i use the watecooling to heat my "heat bank" innside my home aswell Regards from cold snowy Norway:)

[@DavidPozEnergy]

That's awesome. What heat exchanger did you use from the engine coolant, to your hydronic fluid? I'm currently looking at some different options. I'll be setting up a CHP (combined heat and power) in the future. Yes, I have a 250 gallon tank under my home that I built. It's connected to three flat-plate solar collectors for heating DHW (domestic hot water).

[@trygvetveit4747]

@@DavidPozEnergy :) First, my system is more complex than first told, But to extract heat from the gen set i use a plate exchanger taken from a scrapped Water-Water heat pump. Just add a thermostat and a controlled valve to take heat from your engine at running temp. My system can take heat from other sources aswell, like now im in the prossess of building å Peterson Wood Gasifirer, and i will modify it to watter cooling.. Like you i got 20kW solar, ca 100kWh battery , a small pelton turbine 2 kW and two homemade solar hot water collectors (i use cheap plate exchangers from china. Btw i use Victron, one multiplus2 8000 and one Qattro 10000 to adjust load from the Generator...

[@trygvetveit4747]

@@DavidPozEnergy Regarding Taking heat from the Generator, i propably will add a EGR Cooler to the exhaust aswell, as i got two from a freind who did not use them

[@DavidPozEnergy]

Sounds great.

[@edgewood99]

In the meantime...its SUNNY outside again...and the whole point is MOOT! (or MOO if you are Joey T. "the opinion of a cow" )

[@thephilosopher13]

11:01 did you wrap it with heat shrink, and then tape it instead of heating it up….? I’m confused!

[@DavidPozEnergy]

The heat shrink is just being used as a sleeve. I didn't heat it up. I taped it so that it wouldn't shift. But, the whole setup was just temporary for the one day, so I wanted to easily take it apart.

[@thephilosopher13]

@ I figured there had to be a logic I just didn’t see lol. You’re quite a clever person 🤷‍♂️ people do seem to be losing IQ points for the last couple of years though!

[@mark_osborne]

I was thinking about belt-driving an old Ford 1G alternator (or something like that), but then I thought to myself -- "that's just stoopid !"

[@DavidPozEnergy]

LOL. we have both done that.

[@robjohnston8632]

Another great video David! As you said the Kohler engine is a bit more efficient. Is it possible and potentially even worth swapping the power heads on the Kohler from the Kubota and retesting? Might be worth doing when you do your heat and power test (CHP)

[@DavidPozEnergy]

I'm looking around right now. I am seeing if maybe a light tower comes up for a couple hundred that has a blown engine, but a 240V head. The Kubota is perfect as is, so I don't want to mess with it.

[@stevec5000]

What is a chargeverter and how is that different from a normal charger?

[@DavidPozEnergy]

"Chargeverter" is the name for one model of charger. It's sold under the EG4 brand by Signature Solar. I linked to it in the description, but here is the link also: signaturesolar.com/eg4-chargeverter-gc-48v-100a-battery-charger-5120w-output-240-120v-input/?ref=4_rHcgZ9x-TiF- (affiliate link) It is a 100A charger that can accept 120V or 240V AC (even 208). It is made for lithium batteries as a CC/CV charger. That means constant current until you hit the set Voltage, then constant Voltage. This is different from an old-fashioned charger that is built for lead acid batteries.

[@stevec5000]

@@DavidPozEnergy OK, thanks. Amazon doesn't carry that but they have a 50A model so do you really need 100 Amps? That seems like overkill.

[@DavidPozEnergy]

Depends on your own setup. Most batteries don't want to be charged at more than a 1/2C. So, if you have a 48V lithium battery (call it 50V for easy math) and it's 100Ah, then you don't want to charge it more than 50A. 50A is half of the 100Ah capacity. My battery bank is over 2,000Ah. If I charge it at 100 Amps, it will take 20 hours to re-charge. But, I could charge it at 1,000 Amps and be done in 2 hours. The limiting factor for me is the generator capacity, not the charger. Charging faster is preferred since nobody wants to listen to a generator run all day. Also, oil changes would be more frequent.

[@arnecarlsson9740]

👍👍👍

[@reginaldpotts2037]

Why don't you look into making fuel with excess solar in the Summer to run a generator in the Winter.

[@beckfordelectrical]

When should we be expecting the load test of the XWPros?

[@DavidPozEnergy]

Did you mean this one: kzbin.info/www/bejne/pHS5YoKLp8h0l9ksi=j7Vmmmkf6hofmJr6

[@beckfordelectrical]

@ that’s for one XWPro. Now we would love to see with both XWPROs. That would be a good idea. I recently bought two but didn’t get the chance to test them as am working abroad. 😂

[@DavidPozEnergy]

OK, thanks. I don't have plans for that right now, but will add it to my list of video ideas. From what I've observed running the past year on two, is they share the load well. Sometimes one has a hundred more Watts than the other, but very close.

[@mornepietersen5512]

Hi How is the wind there in winter time, maybe you could look into wind turbines

[@DavidPozEnergy]

Yes, that was my thought a few years ago. Unfortunately, I'm in a little spot with nearly no wind.

[@ThisRandomUsername]

Nice test! When I saw the values for gasoline I was really confused. It looks a bit like 59kWh/gal and 49kWh/gal for your 2 generator setups. I was wondering how diesel was so much less efficient than gas.

[@DavidPozEnergy]

There is a decimal in there. Maybe I can try a different font to make it clearer?

[@ThisRandomUsername]

@@DavidPozEnergy Yup, figured it out when I went back afterwards. I like that Diesel is so much more efficient, especially for far off grid setups, because you can keep it a lot longer and somewhat replace it with vegetable oil in a pinch.

[@DavidPozEnergy]

Yeah, diesel is better than gasoline for off grid generators. I'll do an alternative fuel video soon (in 2025). Also, I've converted vehicles to run on vegetable oil in the past. If you go way, way, back in my videos you can find some.

[@joesilvasr9733]

Why not charge the battery bank directly with a DC alternator/generator? There are quite a few DC generator heads available. There should be no charge verter losses.

[@DavidPozEnergy]

I've done a couple builds of DC charging generators. The ones I built were not as efficient as this. But, I'm always learning. Do you know of a DC head available that might fit this engine?

[@joesilvasr9733]

@@DavidPozEnergy I'll send you a few links.

[@industrialmonk]

You are still wasting the heat from the water cooled engine's. This could help heat your home and increase the efficiency dramatically. I wish I could get that Kubota generator cheap in the republic of Ireland i would water cool the exhaust & connect it to my house heating.

[@DavidPozEnergy]

I'll be doing a CHP (combined heat and power) in the future.

[@markhischier2750]

​@DavidPozEnergy , I found a low hour Honda 6.6kW gasoline gen from an ambulance ($200). It's water cooled and my home is hydronic with 375 gallons of thermal storage. I'm going to convert to propane to draw from my big tank and bottom cycle it. Running my heat pump at 4kW elec and scavenging the waste heat should give me 90,000 Btu per dollar of propane ($1.85/gal). Way more expensive than grid power through the heat pump (166,000 Btu/$ @ $0.72/kWh)