Why do we need external Generators?

[overlander63]

Originally Posted by tvoneicken

If I have a good alternator in my truck, what would it take to recharge the trailer batteries from 50% to 80% or 100%? I currently carry a yamaha gen for this purpose but virtually never use it. It would be awesome to save the ~80 lbs.

The usual amp output on a TV charge line is 10-15 amps. Charging two batteries means halving that per battery, so 5-7.5 amps per battery. Putting 30 amp hours back into each battery would take up to 8 hours of running the tow vehicle.
You CAN direct wire to the trailer batteries, which would increase the charge rate, but that would again depend on amp rating of the TV alternator, size of charge line, length of charge line, number and type of connections.

[soddbbuster]

Thanks to everyone who replied. I guess I was thinking of the space that the external generator takes up. Unlike a motor home, an airstream trailer doesn't have a lot of external storage compartments. I did have an airstream land yacht in 91 and the generator made as much noise as a truck engine running on idle. I only used it a couple of times so I'm relying on memory. Also in the forum I've read where the external generators get stolen even when chained down to a tree with logging chains. When staying in parks I'd of course plug in to the electric outlet, but I have some very rural properties where there is no electricity, and no neighbors to complain. I just thought the truck manufacturers would have thought of some solution to fill a need. Just think of all those folks in the northeast that had no electricity when the trees fell on the powerlines. I'd love to be able to power my house with the truck engine... with the appropriate attached gismo.

[dznf0g]

Originally Posted by tvoneicken

The factor that is missing in this discussion IMHO is what the use-case is. If the purpose is to have a gen running all day/night to power air-con or such, then I agree with everything that has been said. What the original question spurred in my mind, though, is the use of the truck to recharge batteries when the solar fails due to weather or similar. If I have a good alternator in my truck, what would it take to recharge the trailer batteries from 50% to 80% or 100%? I currently carry a yamaha gen for this purpose but virtually never use it. It would be awesome to save the ~80 lbs.

You're not going to save any weight....maybe space. By the time you mount the underhood gennie, add brackets, possibly a proper ratio pulley on the crank, add the large guage wire to connect up to....you're going to be at every bit of 80#s, IMO.

[Wazbro]

When they first started making the Silverado Hy-brid it was setup from the factory to use it as a generator, not sure if the new ones still are but they only have a 6000lb tow rating.

[Foiled Again]

Originally Posted by tvoneicken

The factor that is missing in this discussion IMHO is what the use-case is. If the purpose is to have a gen running all day/night to power air-con or such, then I agree with everything that has been said. What the original question spurred in my mind, though, is the use of the truck to recharge batteries when the solar fails due to weather or similar. If I have a good alternator in my truck, what would it take to recharge the trailer batteries from 50% to 80% or 100%? I currently carry a yamaha gen for this purpose but virtually never use it. It would be awesome to save the ~80 lbs.

Honda makes an EU1000 generator which is the size of a bowling bag - and works great to power a battery charger, fans OR your hair dryer. If you're not looking for max power it's handy to have.

Paula

[dznf0g]

Originally Posted by Wazbro

When they first started making the Silverado Hy-brid it was setup from the factory to use it as a generator, not sure if the new ones still are but they only have a 6000lb tow rating.

No they're not. Was not a lot of available amps, and the customer want wasn't there. A contractor or the like could run maybe one circular saw....that's it.

[dznf0g]

Originally Posted by Foiled Again

Honda makes an EU1000 generator which is the size of a bowling bag - and works great to power a battery charger, fans OR your hair dryer. If you're not looking for max power it's handy to have.

Paula

Hmmmm....DW's hair dryer is 1850 watts????????

[ROBERTSUNRUS]

Originally Posted by Foiled Again

Honda makes an EU1000 generator which is the size of a bowling bag - and works great to power a battery charger, fans OR your hair dryer. If you're not looking for max power it's handy to have.

Paula

Hi, I use a solar hair dryer; I go outside for about 30 minutes.

[urnmor]

The one challenge that I see is what if you ant to go some place. You would have to disconnect the vehicle each time; not so with a stand alone generator

[newroswell]

When you start comparing price, watts, weight, price, noise, price, ease of use, price, fuel consumption, it's nearly impossible to beat a Honda EU2000. If you want to run the A/C then you have more to consider. Lots of reading in the generator threads on the best way to power an a/c via generator.

[ROBERTSUNRUS]

Originally Posted by urnmor

The one challenge that I see is what if you want to go some place. You would have to disconnect the vehicle each time; not so with a stand alone generator

Hi, this is something that I'm thinking about because if my next tow vehicle is a pick-up truck, I plan to mount my Yamaha 2400 to the truck bed. I don't think that I would leave my trailer with my generator locked and running anyway.

[Splitrock]

I worked with truck shop service men in my 20's. Those guys had service trucks with semi type engine driven air compressors and storage tanks, engine driven electric generators, and 220 volt electric welders. They could jump start, charge a battery, weld a broken dolly, mount and air up a tire, and power work lights.

Railroad service trucks are set up about the same.

[overlander63]

A few years ago, when there were ice storms and blackouts in the Northeast, a railroad helped out by running a locomotive off the tracks, down the street, and parked it in front of the local emergency services building. It was hooked up and powered that building and several others for about a week. Having to repair the grooves in the pavement was a small price to pay for having power.

As for the engine mounted generator, I don't think anybody said it was impossible, just inconvenient, inefficient, and not being a good neighbor at a campground. And I've charged batteries and jump started cars and lawn tractors using generators.

[dznf0g]

Originally Posted by overlander63

A few years ago, when there were ice storms and blackouts in the Northeast, a railroad helped out by running a locomotive off the tracks, down the street, and parked it in front of the local emergency services building. It was hooked up and powered that building and several others for about a week. Having to repair the grooves in the pavement was a small price to pay for having power.

As for the engine mounted generator, I don't think anybody said it was impossible, just inconvenient, inefficient, and not being a good neighbor at a campground. And I've charged batteries and jump started cars and lawn tractors using generators.

Absolutely, it is doable, and is done all the time with many of my commercial/fleet accounts, both belt driven as well as PTO (not many PTOs, because these trucks typically also run something else with PTO, like a hydraulic pump, etc.)

As stated above, for our camping application, IMO its benefits are very much outweighed by its drawbacks.

[benjisgal]

Be nice, Carl. All of us are apparently not as keen as you are. I love the question and the answers.

[marzboy]

Usually a car/truck alternator is not adequate to re charge a battery. Especially one that is drawn down past 10 amps.

[mike_s]

to run a genset off a PTO, you will need to run some pretty high RPM's. (unless they genset has a reduction gear in it.)

A genset needs 3600 SHAFT RPM to maintain 60hz. that's not 3600 engine RPM, as the transmission reduces the shaft RPM.

I don't know if PTO generators have gearing in them, and don't know what your truck would required for the generator to run that fast. but it should be clear that this isn't the best way to do it.

[Friday]

I think the answer is simple... to meet ever more stringent emissions and mileage requirements, adding any more gadgets to the engine that would affect either negatively is a non-starter. The more complicated answer is that engineering a generator that puts out meaningful power, stuffing it in the engine bay, then dealing with the liability issues of people frying themselves just isn't worth it for the small number of people that would ask for it. Having any kind of external, rotating PTO on a consumer vehicle would be inviting disaster.

PTO's on tractors were there because 90% of people used them... the other 10% of people were twisted up like liquorice in them...

[Grams]

I have a Landyacht with a Onan generator. The generator has over 800 hours on it. My unit was constructed in 2002 . I am wondering what the life of the generator is.

[Jammer]

Hi Sodbuster. Welcome to the community..

In general the installed cost of a truck-mounted, engine-driven generator will exceed the cost of a freestanding generator of similar capacity.

I've also penciled out some systems with large battery banks and inverters on the tow vehicle but couldn't make these practical either.

If the main goal is battery charging then that can be accomplished with the existing truck alternator. For people who want to run air conditioning, a freestanding generator is necessary.

I don't have a generator and doubt if I will get one in the foreseeable future. We plan our trips so that we don't boondock when and where there are hot nights where it makes sense to run the air.