Charge Batteries by Idling Tow Vehicle?

David ... I'm curious. Where on the 270A alternator graph you posted does it give the temperature at which it's single curve applies?

The 3G, 4G, and 6G Ford alternators are rectified WYE alternators and have decent low speed performance. But they are NOT hairpin alternators. The G alternators (G stands for Generation) with 130-amp stators have PURPLE insulation coating on the stator windings. The lesser amperage G models have GREEN stator windings.

Yes there are hairpin alternators that have correct bolt mounting for many Ford engines. Two cautions: Adapting the voltage regulator plug and adapting the pulley. Both are unique and both must be compatible with your G mounting configuration.

Take LOTS of images with your camera using as many shooting angles as you can of your existing alternator. Especially of the regulator and inside the pulley and belt interface. Take them to your Ford dealer then begin the search. As far as I know Ford does not sell the voltage regulator pigtail for the hairpin which by the way is a Nippondenso creation, not a Motorcraft.

The hairpin curve is a hot temperature curve and from experience I can tell you the hairpin outperforms the rectified wye alternator at low speeds far and away more than "double". Try triple to quadruple. Any comparison is a real eye-roller. At 120 rotor RPM a 270-amp hairpin will be capable of producing a not insignificant amount of power. The performance chart that was mentioned does not do the issue justice.

My Lambordini cannot crank the Delco if the regulator is switched on with the engine's starter motor trying to turn the engine over. Absolutely locked rotor condition. This is with a 2.14 horsepower Magnetti Marelli starter. A 13-ampere rotor draw is significant (24-volts). That should give some idea of the field strength needed to saturate the windings and laminations.

Time to get out the flashlight and mirror and go look at your stator winding color :)

pianotuna wrote:
Ok hairpin alternator--but is there a brand name? Or one that is easily available for a Ford v-10 in an E-450 chassis?

Don ... I may have missed it, but I don't think I saw a definitive/clear answer to your question other than some suggested aftermarket alternators.

Perhaps/probably your(?) E450 V-10 already came stock with a "Hair Pin" configured alternator.

Study the Ford stock 130 amp alternator curves that I linked to, earlier, representing the alternator that came in our 2005 V10 E450 Itasca. Now study and compare those to the 270 amp Hair Pin alternator curves that Mex showed. My conclusion is that my stock 130 amp Ford alternator performs almost identical to the 270 amp one - except for delivering around 1/2 the amount of current at all RPM points.

Does this mean that the stock Ford alternator is a "Hair Pin" one .... and a pretty good one, at that? I'm willing to bet "yes". :C

P.S. So far I haven't ruined my alternator by letting it dump huge currents into our AGM battery bank with the V10 only running at idle RPM. Maybe I should knock on wood ... after all ... I did manage to ruin my rig's original 5R110 E450 transmission after only ~51K miles!

This is like connecting a 4" fire hose to a garden spigot. Someone here may point you to images and links to install a rational charge lead line with separate socket and plug using TWO GAUGE WIRE, all the way under the truck, past the hitch and into the trailer direct to the battery terminals. With a run that long you MAY get as much as a seventy or eighty ampere POTENTIAL charging rate. A friend is doing this with 1/0 wire. The connectors are dependable because they are used on big rigs to power trailer lift gates. My connectivity is very limited today. Sorry no links.

I didn't read all 42 posts. Sorry if i cover same ground.
Our F350 had two alternators and two large batteries.
It had a 20 map fuse to connector to Fifth Wheel.
We charged the batteries, it originally only came with one, in our fifth wheel, by idling the engine in the pick up.
It had been at service for some reair, for a looong time.
They let the batteries run down. When we tried to raise the front to hook it to he truck of course it wouldn't go. They hooked up the harness and it went a bit before it blew the 20 amp fuse. Took a while to find an auto parts store, with that particular fuse. A under hood box had every other fuse you could thing of though. Replaced fuse let it idle for twenty or thirty minutes disconnected the lug an jacked it right up.
The house battery should charge from your pickup.
When we installed the plug on the pickup we bought a heavier unit and with ten gauge wiring and soldered the connections.
A good bit of current goes from vehicle to house battery.
used dialetric compound on pins of connector too.
use a good connector that is weather tight when hooked up.

Hairpin is NOT NEW technology. Every 50DN Delco alternator is hairpin and has been for 40 years.

When I start the Lombardini, it has a 1-2 ratio with the alternator. 2,000 engine, 1,000 alternator. At 2,500 RPM the Delco delivers 217 amperes @ 28 volts. At 3,000 - the full 385 amperes. This is a 24-volt unit meaning 385 amperes really means the equivalent of SEVEN HUNDRED SEVENTY AMPERES of 14-volt energy.

The idea is high amperage at LOW engine speed. It's insult enough to have to run 8-cylinders to get 120-amps. If you have to rev the engine to get the 120 grab the nearest conical shaped hat. My bus dead slow idles the 28 volt Niehoff at around 305 amperes. Equal to 610 amps of 12 volt energy.

The ND meaning Nippondenso is a factory produced hairpin.

ALL my alternators, The 50DN and the NIEHOFF have my own external rectifiers and external voltage regulators. I want ambient temperature air to blow by the stator windings not pre-heated air.

The Lomhardini/50DN has a 1/4" stack of irradiated copper plates and six VA 1,675 ampere, rectifiers. Think 1/0 rectifier braid with 1/2" holes (Plating plant rectifiers). Also think dual ball bearing 28 volt fan that passes about a thousand times more air across the copper stack.

Back in the 70's I purchased one KG of colloidal silver. Mixed generously with GE silicone grease, and colloidal beryllium, I made the best heatsink grease on the planet. The beryllium powder is poisonous. I wore a respirator and looked like a Hazmat worker as I mixed it and the silver into the grease. All went into a 6 liter lexan lab jar. I'd hate to try and price it all today. But because of the beryllium I cannot user it on consumer goods like my LED lamps.

With my Dodge Spirit junktoad, I'm going to get a 120-amp Mitsubishi alt, to replace the pathetic 40/90 Bosch, rip into it, and do a triple delta 16-3/4 gauge stator at Lund & Flynn, remote mount a rectifier package in the trunk and use one of my leftover Transpo F540SP voltage regulators (and a dollar 10 ohm 50-watt resistor). Time to mount a 31 Lifeline in the trunk. The new 2-story Lifeline is going into the house. If I can't get 100-amps at dead-slow idle I will be surprised. Perhaps at speed, 185 tops, hot. Converting existing car bracketry for a hairpin would be a nightmare on steroids.

I see more than 80 amps into a single Northstar group 27 on my 120 amp alternator, and this is just a 50/120 chrysler alternator.

I've seen it do 110 amps, and no hairpin every found its way near my alternator.

But Idle speed output is hardly impressive when it is hot.

If it were, A 4 inch bilge blower would be blasting ambient air at it.

But soon I will have Alternator temperature data and theory can then take a back seat to reality, again, maybe.

David,

Since your chart above is of a 270-amp Hair Pin alternator and since your chart indicates about twice the performace shown in the chart I posted showing the performance of the stock Ford 130-amp alternator in our 2005 V10 E450 ... does that mean that at least in 2005 chassis models Ford was installing some Hair Pin type alternators, stock?

It looks to me like that might be the case.

FWIW, our alternator spiked to 80 amps a few days ago when I first started up V10 for an hour long coach battery charging session.