Post by: Glennman

I have a 12 kW Kubota generator (Wrico) installed in my 1974 MCI. I plan to get rid of the bus, so I'm thinking of putting the generator in my 2002 MCI. Currently, I do not have a generator in this bus.  I only have solar. My thinking is that I really don't need 12 kW, since I would only need to charge my system on cloudy days, etc. That being said, is a 12 kW generator too much power, since it would be charging through a mere 3000W Victron Multi-Plus? Would I only be wasting fuel?

Post by: Gary Hatt - Publisher BCM

I had the 12kW Wrico in my Eagle bus too, and it is a great generator. It is overkill for what you need unless you are running 2-3 A/C units.  It will drink about 5/8 of a gallon of fuel while running, but they are great generators. If you already have one, why not use it?

The downside is that a small 1,000W Honda generator is all you really need to charge your batteries on a rainy day, and it is much easier to move around.  But they run on gas, not diesel, and if left outside, are prone to theft in some areas.

Remember, too, if you install a diesel generator in your bus, it will need a diesel fuel supply and return line, which is a bit more work.  But that way, you are only dealing with one source of fuel in your bus, unless you also have propane appliances.

Post by: Glennman

Thanks, Gary. I watched a video of a guy who found a used 4 kW diesel generator and got it running. I would trade mine for the smaller gas generator in a minute. I hate the idea of installing that beast for what little I would need it. I prefer not to use gasoline either. I'll wait it out for a while and see what comes up in the used market.

Post by: luvrbus

You should be able to buy a used light tower from a rental yard with a good Kubota water-cooled engine in the 4,000W to 6,000W range.  You definitely don't want a noisy, air-cooled China-made 4,000W diesel generator. What does a 12,000W Wrico generator sell for?  I know the 12,500W Onan QD costs almost $20,000 now, including shipping and taxes.

Post by: belfert

You might be a good candidate for a gasoline inverter generator.  I know they won't last as long, and exhaust is an issue, but they work well for smaller loads.

Post by: luvrbus

You can buy a used light tower with a liquid-cooled diesel engine for $500 to $1,000, and they are very quiet.  I bought four for a project from Iron Planet.  I only paid $750 for one with a total runtime of only three hrs.  It had been wrecked.  I didn't care about sheet metal damage.  All I wanted was the engine and generator.  I know you can buy light towers all day long for under $2,000, with 3,000 to 7,000 hours of runtime, and they last over 20,000 hours before requiring service.  You have a lot of engine options for the light towers.  I had two with Kubota engines, one with a Cat engine, and one with a Yanmar engine.  They are only 10-12 HP.  And a quart of fuel will run one for almost two hours.  They all run at 1,800 RPM.

Post by: Glennman

Thanks, luvrbus. I'll have to look into that!

Post by: Glennman

Back when we were traveling from Springfield, Missouri, to Waco, Texas, we had to run the mini-split the night before leaving while it was pouring rain. It was so hot and miserable that we couldn't sleep. By the time we got to Waco, because we couldn't fully recharge the system and were driving in cloudy weather, we ran completely out of power ten minutes after pulling into our friend's driveway. We were luckily able to hook up and get things charged. That is what's driving my inquiries into the whole generator thing.

I got to thinking that, since my mini-split is the largest draw I have, suppose I installed a dedicated 24V-to-110V inverter, connected it to the bus system, and ran the mini-split on that while driving. Then I can just plug the mini-split into the house system when I reach my destination. That would take away most of the need for a generator. What do you think?

Post by: dtcerrato

We sometimes run our roof air on the inverter, with the battery bank feeding it and being charged by the engine alternator, to save fuel on the generator.

Post by: belfert

Yes, you should be able to connect a 24V inverter to the coach's electrical system.  I did it on my bus for a number of years until I switched to 48V for my house batteries and inverter.  I recommend a Victron 24V inverter without a charger.  They are good units that are fairly inexpensive.

On my Dina, I removed the coach A/C as it was badly broken, and very expensive to repair.  There is a large solenoid in the back that powers the A/C system.  I used the solenoid's output as the 24V feed to the inverter.  I ran a control wire to the front of the bus to turn the solenoid on and off.

Post by: Glennman

I'll look into the Victron without a charger. I know this is getting even deeper, and I am somewhat lacking in knowledge, but would a DC-to-DC charger achieve the same goal? Or, suppose a guy connected a 3000W inverter/charger to the bus system and used it not only to run the mini-split but also to charge the house system? Am I crazy?

Post by: belfert

A DC-to-DC charger can also be used to charge your batteries and supply your inverter. However, you will be limited on how many amps are supplied.  Victron also makes these.

Post by: luvrbus

DC-to-DC chargers don't deliver enough amps to replace the power your AC uses.  I see people with four DC-to-DC chargers on large battery banks. I installed the 12/12/50 Victron DC-to-DC charger on my daughter’s RV, which has two 105A LifeP04 batteries.  It won't keep up if you use any AC power while driving.  The DC-to-DC chargers are designed for LiFePO4 batteries.  They are useless on flooded-type batteries, I was told.  Victron’s answer to the problem was to spend another $200+ and use one for each battery.  If an alternator could charge the high-dollar LiPo4 batteries, I would toss the Victron DC-to-DC charger.

Post by: belfert

If using lead-acid batteries for a house bank, you can set them up at 24V and connect them directly to the chassis system.  Your charge profile may not be perfect, but it works pretty well.  You will need to center-tap the battery bank for 12V, and it is best to use an equalizer to keep the batteries balanced.  (I have a no-longer-used Vanner Equalizer I would give you, or charge a token price for.)  I have done this in the past before I switched my house battery bank to 48V with LiFePO4 batteries.

In this case, you would need an inverter with charging, as you would want to replace your 12V inverter.  You really don't want to run an inverter off a center tap.

Post by: luvrbus

If I had to do things over, I would have bought a Renogy DC-to-DC charger, as the higher-end Prevost uses, or a Victron smart charger.  Redarc is a good charger.  You see a lot of those chargers.  I don't know about the pros and cons of the Redarc units.  I know they are expensive. My Country Coach used the Echo charger to keep the chassis battery charged when on shore power.  I like that feature.  It took care of all the fantom draws on the chassis.  I would not own an RV without a generator with all the electronic crap continually being added to them.

Post by: belfert

Generators can fail, too.  My previous generator failed almost every year for four or five years.  We started to carry a Honda EU2000 generator as a backup to keep the basics running.  I finally got sick of the generator issues and bought a Wrico generator.

Post by: Glennman

I ended up ordering a Renogy 24V/2000W inverter. It will be dedicated to the mini-split while driving. I suppose I would still need a generator for boondocking when it's hot both at night and during the day. I now have a 24V mini-split unit (like the ones for truck tractors) in the bedroom that runs on the bus system while driving. It's set up to connect to the house batteries when parked. We can run it on low and benefit from it at night.  The Pioneer mini-split unit is far away, hanging above the windshield, while using a lot of power. I have yet to use it as I installed it just as the cold weather started.

Post by: luvrbus

My Universal marine generator ran for many years, with me replacing only the shutdown solenoid. Powertech had problems.  I helped Sonnie Gray change the head bearings several times. Onan had problems with the magnets coming loose after Cummins bought it.   

What I like about Dick Wright’s generators is that he didn't use all the electronics.  Just plain and simple, and they run forever.  I am not a big fan of Powertech.  Gary's new Prevost bus has had the 20 kW Powertech removed and replaced with a Wrico generator.  I like the Martin generators with Yanmar turbo-diesel engines.  They never give up. That is why the entrainer buses use Martin.  Onan is the most popular RV generator by far due to the service network.  All Cummins dealers will work on Onan.

Post by: luvrbus

I like the Renogy products.  They use a lot of it here in the valley for solar applications.  They are affordable and customer-friendly.  Renogy has a large warehouse and center not far from us in Chino, CA.  People here like that level of support.