Two. Two alternators! Ah ah aahhh ....

[Zizzer_Zazzer_Zuz]

Yup. My 2005 Ford E450 Shorty Bluebird School has TWO alternators! WTF?!? I'm thinking one was for running the wheel chair lift.

I have a solenoid and an inverter that I would like to run directly from one alternator and let the other charge the starter batteries. I've found a copy of the Bluebird wiring diagrams but hadn't gotten that far until now.

Any thoughts, insight, or suggestions would be very much appreciated. I see some interesting switches in my future to send the magic blue smoke where I need it.

I'm a bit stunned by this revelation about the alternatorS.

 

[John61CT]

Dedicating an alt to starter batt is overkill, put both directly onto a quality large high-CAR House bank and run your loads from there.

Will still need solar for the long tail, best for the bank is driving first then lower-amp solar.

An Echo Charger or inexpensive ACR will keep the Starter topped up just fine, inexpensive FLA best for that.

 

[user 423]

I wonder if they have internal regulators? How is your bus titled/tagged?

 

[highdesertranger]

dual alternators is factory on many diesels. it's for heavy duty options like multiple battery banks. highdesertranger

 

[Gary68]

i might go 2 alternators and since it is a chevy i can get a one wire alternator for it

 

[Scott7022]

Dual alternators are available for a lot of trucks, but are rarely added on for lot inventory ordered rigs. So long as you stick to lead acid chemistry it is easy breezy. To get the most bang for the buck upgrade the grounds, feeds, and charge wires to cables. If you have a single engine battery grab some top posts clamps that have dual 1 gauge connections and eight gauge built into the terminals. These are great, if you buy good quality units. https://www.sonicelectronix.com/item_68647_Kicker-Battery-Terminal-BT4.html No crimps, no fuss, and easy to measure and fit well. 0 guage cable is good for power, ground and eight gauge for excite. Overkill actually, but, it makes the biggest difference for the least money. 4 guage cable would probably be suffient but at two bucks a foot and three bucks a foot why save 10 bucks? Come off the positive terminal with the empty 0 guage to a fuse mounted as close as you can and rated above your alternators combined output. Use a meter safety is a really big issue here. Use a good fuse in a water resistant case and you need two. Like this one http://stingerelectronics.com/catalog/power-distribution/water-resistant-anl-fuseholder. Come out of the fuse and into a combiner/relay rated above the current you measured as well, like this http://stingerelectronics.com/catalog/power/SGP35?search_query=relay&results=5. Some people like so called automatic relays that connect when the vehicle is started and disconnect when engine is off. Others like true intelligent automatic relays that sense voltage and connect and disconnect. I personally like BlueSea latching relays, but they are expensive. https://www.bluesea.com/products/76...rging_Relay_with_Manual_Control_-_12V_DC_500A If you are under 250 amps of current and the wire length is around ten feet or less from the relay side to the battery bank then 0 guage COPPER wire is fine (Capacity per ABYC Standards: 285 amps.). Connect the end to your other fuse and then from the fuse to the house bank. Keep fuses as close to the batteries as you can. This allows both alternators to push energy to both engine and house batteries and will spread the work out for the bulk cycles. If you lose an alternator you still get a charge. If you want to get fancy you can add a sense line to each alternator and run dual volatge meters, so you'd know if you lost one.

Personal note. I upgrade grounds and do the single point ground as I tend to hear whining more than others and have a hatred of ground loops. While wire isn't exactly cheap I still add 0 gauge grounds in the engine compartment and run back from that ground to the house negative side. Yes, I know it is not required, may be stupid even but I once spent too many hours chasing a ground loop. For 10 feet of four gauge cable, and while I am under the rig pulling wire anyway I just do it.

 

[speedhighway46]

Dual alternators . . . I am so jealous!

Installing dual alternators on my Peterbilt motorhome has been a long standing desire and hopefully will start the project next spring. I have to visit my local Caterpillar dealer to see if a "kit" is available for my C-15; if not I'll have to design the installation and have some custom mounts fabricated.

Two alternators is the way to go; one complete charging system for the starting system, and another complete system for the house system. If one should fail, you can switch to the other.

Just my opinion . . .

 

[Optimistic Paranoid]

Dual alternators are a common option on ambulances.  However, I'm under the impression - I could be wrong - that both feed the same battery bank, not separate banks.  They are needed to power medical equipment while the ambulance is running.

 

[frater secessus]

I think some of the Roadtreks have an optional alt that feeds the house system. IIRC it's used instead of a generator; not sure I like that idea.

 

[Scott7022]

Dual alternators are a common option on ambulances.  However, I'm under the impression - I could be wrong - that both feed the same battery bank, not separate banks.  They are needed to power medical equipment while the ambulance is running.

The ones I've seen, still working, and the ambulance/camper builds it is a one circuit with a engine on/off disconnect. Creating dual charging circuits and the sort is when you start seeing terms like voltage drop and other terms tossed around by experts. Most modern large consumer trucks have Fire Chief/Snow Plow prep/Camper Prep or "other" terms for dual alternators. Dodge just calls it Dual alternators or High Output or Regular output singles. Some get included in other packages. It is not rocket science to add one, providing one has the space and if you wanted to add a one wire old fashioned separated from the computer system. Mechman Alternators have been custom making them for years the boys can build anything you like. 200 amps at idle with an external regulator diode pack suitable for 100% duty cycle, no issue write a check. Going this route I would separate the systems as stock wire is not going to handle that kind of monster. 

The starting battery is going to use the alternator for perhaps 10 minutes to recharge the bump pulled in starting. Less if it ain't diesel and cold. The factory system is designed to do just that. Nothing more. Hence why diesels have two. Outdoorsman or Camper specials et all Corporate names add an additional unit to lessen the strain on the single generator. Not charge a 400amp/hr battery pack. Ambulance rigs get a ton of electric  upgrades as they have to be certified, at least in Canada, as do Police cars and Fire Trucks. We get a special brochure and I know it is the same one the USA police agencies get. I don't know about the certification process. A dead battery during Game Of Thrones is a bad time. A dead defibrillator because the charging system failed is a lawsuit and a bad day. 

You could get all sorts of crazy  

 

[John61CT]

> Some people like so called automatic relays that connect when the vehicle is started and disconnect when engine is off. Others like true intelligent automatic relays that sense voltage and connect and disconnect. I personally like BlueSea latching relays, but they are expensive

Biggest difference is the latter type allows for **all** charge sources to feed both banks.

Former connects the two only when the engine's running, so the alt is the only charge source feeds the bank on the other side of the relay.

The big House bank is the one gets depleted, so that's where all charge sources should connect directly.

Starter batt gets hardly any use, so just about any combiner type will do the job.

But the ML type Blue Sea ACR is very robust, basically never fails.

 

[Zizzer_Zazzer_Zuz]

WOW! Thank you all! Still reading and trying to absorb all of this.

Mechanic is having fun working on my rig which I hope is good. Watching this guy diagnose a hydrolic leak on a Peterbuilt roll-off was fascinating!

Sent from my SM-G920V using Tapatalk

 

[Optimistic Paranoid]

Boats often have dual alternators that feed separate engine and house batteries.  You can get voltage regulators for the house alternator that have that three stage - bulk - absorption - and float built in.

The hardest part of do-it-yourself is fabbing a mounting bracket that lines up perfectly with the other pulleys so you don't wreck belts.  If you can buy a factory part for mounting a second alternator, you're golden.

 

[John61CT]

His two alts seem to already be mounted and working!

But yes, Balmar MC-614 voltage regulator give a sophisticated fully adjustable charge source, could even use with a LFP bank.

But not cheap, if not doing lots of driving most days probably make more sense to stick to a quality FLA bank matched to the existing hard-coded setpoints.

Just verify the internal VR is at least reliable in keeping voltage output steady.

If VR needs replacing, see if ​Transpo 911-02R will work, also adjustable but lots cheaper than the Balmar, not nearly as intelligent.

 

[Zizzer_Zazzer_Zuz]

Soo ...
Will I split the function of each alternator, one for starters and one for house?
Could I connect a 1500watt MSW inverter to the starters for use while driving?
As for the after market Voltage Regulator could it be set to combine the two alternators to do a fast charge with higher amperage? Or will it just not work that way?
I have 2 6v 215ah FLA golf carts built 5/2017 and simply kept on a float since. I may go get 2 more.
Oh ... and yes, there are 2 alternators already installed. I have them and would love to make the most of them.

Sent from my SM-G920V using Tapatalk

 

[John61CT]

> Will I split the function of each alternator, one for starters and one for house?

No, all charge sources to house as outlined above.


> Could I connect a 1500watt MSW inverter to the starters for use while driving?

No, they should run off House, whenever needed, alts are just one charge source (asssuming you aren't driving 10+ hours a day)


> As for the after market Voltage Regulator could it be set to combine the two alternators to do a fast charge with higher amperage? Or will it just not work that way?

Usually one VR per Alt, combined output at the bank. But Balmar does make a Dual version of the MC-612 also investigate "centerfielder"

> I have 2 6v 215ah FLA golf carts built 5/2017 and simply kept on a float since. I may go get 2 more.

Best if all batts in a bank are a matched set including age. But not critical. . .

 

[Scott7022]

Read and absorb that which has already been posted as it answers all your questions. You have lead acid chemistry EASY BREZZY COVER SQUIRLL covered. Keep it simple and safe.

 

[John61CT]

Had to google silly meme

 

[Optimistic Paranoid]

Just about any vehicle post 1990 or so is not going to have a separate voltage regulator.  The voltage regulator function was taken over by the engine control computer.

Frankly, you'd probably need a degree in electrical engineering followed by a lot of study and circuit tracing to figure out if you could SAFELY bypass that and replace it with an aftermarket marine regulator.

And there's really no reason to.  Under normal circumstances, the starting battery starts out at 100% and probably gets pulled down to no less than 95% starting your engine.  The alternator quickly brings it back to 100%.  It doesn't need that bulk - absorption - float jazz the way house batteries, that are pulled down to 50% do.

Btw, a lot of high end automotive audio places are familiar with multiple alternator set-up.  Those uber-loud cars with massive low end bass need way more power for their amplifiers than a single alternator can provide.  I've seen pictures of engines with banks of three or four alternators wired together to power those amps.

 

[John61CT]

VR is usually "internal" that is attached to the alt. The computer does not handle that functionality.

Most any alt can be converted to external VR by a decent auto electrician, and safety is not an issue. Leece Neville sells kits to do so for many of its truck alts.

And of course no one's talking doing this for the negligible Starter batt's needs.

Not even worth doing for House unless you drive a lot.

Some very recent vehicles have regenerative braking etc, and yes those aren't candidates.

But we're not talking about that are we.