2021 E450 dual alternator

[brianjw]

Does anyone have this package, or can anyone help with parts? Specifically with the gas 7.3L.

My RV has the single 210 amp alternator, and I’d like to upgrade to a 240/157a dual alternator setup.

Nobody lists an aftermarket setup yet and the dorks at the parts dept were not just unhelpful, but angry that I was asking... Supposedly without a vin number of a unit with dual alternators, they can’t look at parts diagrams and tell me what brackets/idlers/belt etc would be required.

Thanks for the help!

[ron_dittmer]

rjstractor wrote:

ron.dittmer wrote:
I understood that a chassis with the motorhome prep package has a higher amperage alternator than a box truck chassis. This addresses most people's needs but Brian has some unique plans.

I imagine Ford's ambulance prep package (with twin alternators) would be ideal for his plans. Apparently the Ford parts guy he was working with was too lazy to determine what is needed from the ambulance prep package.

Brian, I wonder if a Helm shop manual for your chassis will identify what you need.

It's a misconception that the ambulance prep package has dual alternators. It does have dual batteries and a 240A alternator and dual alternators is still an option, but the rest of the package has little to do with the electrical system and more to do with the auxiliary HVAC systems, front axle rating and required heat shielding. All of the newer ambulances that I've work with have automatic high idle. Ours do not have dual alternators, since apparently the 240A alternator is sufficient, and we've never had an issue with not having enough alternator output. The prevelance of all LED lighting has helped immensely with this.

And here we have first-hand experience being posted.

Thank you!

[rjstractor]

ron.dittmer wrote:
I understood that a chassis with the motorhome prep package has a higher amperage alternator than a box truck chassis. This addresses most people's needs but Brian has some unique plans.

I imagine Ford's ambulance prep package (with twin alternators) would be ideal for his plans. Apparently the Ford parts guy he was working with was too lazy to determine what is needed from the ambulance prep package.

Brian, I wonder if a Helm shop manual for your chassis will identify what you need.

It's a misconception that the ambulance prep package has dual alternators. It does have dual batteries and a 240A alternator and dual alternators is still an option, but the rest of the package has little to do with the electrical system and more to do with the auxiliary HVAC systems, front axle rating and required heat shielding. All of the newer ambulances that I've work with have automatic high idle. Ours do not have dual alternators, since apparently the 240A alternator is sufficient, and we've never had an issue with not having enough alternator output. The prevelance of all LED lighting has helped immensely with this.

[Rick_Jay]

brianjw wrote:
I’m going to run a 400 amp hour lithium battery setup. I want to be able to run the roof top AC off of the Victron inverter while driving (or just quickly recharge the batteries while driving). The plan is to run a 60 amp sterling B2B charger off of each alternator, for a combined 120 amps to the lithium battery bank. I don’t want to overwork/overheat a smaller single alternator asking too much from it, and this seems like the safest way to do it. A little overkill, sure. No, I don’t want to have to rely on the generator while I’m driving. In fact if the solar and alternator perform well enough the generator will come out.

Just a question: Wouldn't it be cheaper and easier to just pick up a spare of the alternator currently installed on your rig and IF your original alternator bites the dust, you can just swap it out? A 210 Amp alternator is pretty beefy. And once you have original one out, you can probably rebuild it (oftentimes it's the brushes that wear out) and it'll be ready to serve as a spare.

First of all, as many can attest, IF you have a spare part...you rarely need it...so you're almost guaranteeing trouble-free operation for as long as you own the vehicle! 🙂

Second, you're putting off the work until later...if ever. Ok...that might just be me, but I'm known for "never do today what you can do tomorrow!" LOL

Lastly, I'd NEVER get rid of a functioning generator in an RV. IF you ever go to sell it, I think a lot of people will see that as a red flag. And if you're going to keep it, it needs to be run periodically anyway, and we do that while travelling down the road, keeping the A/C's running. And ten years ago when a freak October snowstorm came through knocking out power for almost a week, there's something comforting about having a generator with a 75 gallon gas tank (in our case). 🙂

Just thinking here...as to the emergency vehicles with the dual alternators, I believe that's because they often spend long hours at idle with their lights on and a single alternator with the engine at idle, might not provide enough juice to keep the batteries charged. Plus, as you said, there is some redundancy, which could be critical in some situations. I also wonder if they don't incorporate a high-speed idle switch as well to get the engine spinning a bit quicker? Of course, newer vehicles use LEDs for lighting, which, theoretically, should reduce the need for as much charging juice during those situations.

Trust me, I appreciate the ideas to mod your vehicle, I like to mod my vehicles as well, though with increasing age, I've scaled back a bit. But on a brand-new vehicle, I'd be really hesitant to do anything to the chassis.

Good Luck, I hope you're able to find the information you need. Please come back and post whatever you find out so perhaps someone else reading these forums in the future can benefit from you experience! 🙂

~Rick

[ron_dittmer]

I understood that a chassis with the motorhome prep package has a higher amperage alternator than a box truck chassis. This addresses most people's needs but Brian has some unique plans.

I imagine Ford's ambulance prep package (with twin alternators) would be ideal for his plans. Apparently the Ford parts guy he was working with was too lazy to determine what is needed from the ambulance prep package.

Brian, I wonder if a Helm shop manual for your chassis will identify what you need.

[pnichols]

Regarding lithium RV batteries being able to accept large charging currents for fast charging - certain top quality deep cycle AGM lead acid RV batteries are capable of that too, due to their very low internal resistance.

In this link see page 20, the second paragraph down from the top - Lifeline AGM RV batteries are capable of short-term acceptance of 500 amps of charging current per 100 AH of battery capacity: https://321166-984045-raikfcquaxqncofqfm.stackpathdns.com/wp-content/uploads/2015/12/6-0101F-Lifelin...

[brianjw]

..

[pnichols]

theoldwizard1 wrote:

pnichols wrote:
Large and reliable alternators will probably become more important as lithium coach batteries become more common in motorhomes. Supposedly lithium battery banks charge fast - but only if one has a charging method that can deliver the high currents that the batteries will accept. For dry camping - especially when many hours of enough solar aren't available - a large capacity alternator driven by an idling chassis engine might be very useful.

First, I would not want to try a put more than 100A into ANY battery for more than a few seconds. Bad things can happen and at that rate they will happen fast !

Second, you really should have a multi-stage charger to do the job properly !

Third, no automotive alternator is going to put out more than 13V "are idle". Typically it takes 1500-2000 RPM to get 14V. Buy a DC-DC charger.

I think that emergency service vehicles often have dual alternators.

And that is the only reason why someone would purchase a vehicle with 2 alternators !

For years (both the coach and chassis of my E450 Class C were manufactured as 2005 models) my idling V10 has spun it's alternator fast enough to, for a bit initialy, put out up to 70-75 amps into my ~50% discharged AGM coach batteries (I use 2 deep cycle 12V AGM batteries in parallel).

I watch coach battery in/out current flow rates on a shunt-based digital ammeter mounted on the driver's side cab dash.

The voltage of the chassis 12V system reads above 14 volts initiallly for a bit, and thereafter for 2-3 hours - as the coach batteries come up to full charge - this chassis voltage remains in the high 13.X volts range. When traveling, after the coach batteries have become fully charged, the chassis voltage usually remains around or above 13.5-13.6 volts.

I watch the above voltage levels on a couple of digital voltmeters mounted on the driver's side cab dash. One voltmeter shows chassis DC voltage and the other voltmeter shows coach DC voltage. Obviously, whenever the V10 is running, both voltages must at all times read very close to the same - if the chassis battery/coach battery interconnect solenoid is operating correclty and with no resistance in it's contacts.

The pulley size for the stock 130 amp alternator is such that the V10 always overdrives the alternator RPM at about 1.72 times faster than the engine crankshaft RPM. The stock 130 amp alternator output versus it's RPM and engine RPM published performance curves support what I see happening on my ammeter and voltmeters mounted on the cab dash.

There is one situation in which the alternator voltage applied simultaneously to the chassis and coach batteries reads in the low 13.X volts range ... that is when traveling in VERY HOT ambient air temperatures. It appears that the Ford systems are designed to provide just about perfect voltages to a lead acid based chassis battery versus ambient temperatures ... which winds up being also what the coach AGM batteries also require and get ... since both battery systems are connected together via the coach interconnect solenoid whenever the V10 is running.

These systems are performing just as Ford and Winnebago designed them to play together. Only the three digital meters that I installed on the dash are non-stock ... so that I know what's going on with these 12V systems as we camp and travel.

[theoldwizard1]

pnichols wrote:
Large and reliable alternators will probably become more important as lithium coach batteries become more common in motorhomes. Supposedly lithium battery banks charge fast - but only if one has a charging method that can deliver the high currents that the batteries will accept. For dry camping - especially when many hours of enough solar aren't available - a large capacity alternator driven by an idling chassis engine might be very useful.

First, I would not want to try a put more than 100A into ANY battery for more than a few seconds. Bad things can happen and at that rate they will happen fast !

Second, you really should have a multi-stage charger to do the job properly !

Third, no automotive alternator is going to put out more than 13V "are idle". Typically it takes 1500-2000 RPM to get 14V. Buy a DC-DC charger.

I think that emergency service vehicles often have dual alternators.

And that is the only reason why someone would purchase a vehicle with 2 alternators !

[brianjw]

Home Skillet wrote:
You can always contact these people and see if they are working on a version for the 7.3L

LINK

Thanks. I actually called them yesterday and I’m waiting for a return call.

[Home_Skillet]

You can always contact these people and see if they are working on a version for the 7.3L

LINK

[DrewE]

Per the Magnuson–Moss Warranty Act, adding aftermarket equipment (including what would be the factory dual alternator setup if so equipped) won't legally affect the vehicle warranty unless Ford can show that the added equipment caused the problem. Of course, the aftermarket bits themselves also aren't covered by the standard vehicle warranty.

The law doesn't stop unscrupulous dealers and companies from attempting to get out of warranty work, but the legal requirements are pretty clear. They aren't allowed to say "You installed a second alternator, therefore we're denying warranty coverage on your failed windshield wiper arm" or whatever.

[pnichols]

brianjw wrote:
It was the Ford dealer parts dept, they’ve historically been awful.

I’m not concerned about warranty, the second alternator wouldn’t be integrated into factory electronics at all. I’ve modified everything I’ve ever owned.

I’m going to run a 400 amp hour lithium battery setup. I want to be able to run the roof top AC off of the Victron inverter while driving (or just quickly recharge the batteries while driving). The plan is to run a 60 amp sterling B2B charger off of each alternator, for a combined 120 amps to the lithium battery bank. I don’t want to overwork/overheat a smaller single alternator asking too much from it, and this seems like the safest way to do it. A little overkill, sure. No, I don’t want to have to rely on the generator while I’m driving. In fact if the solar and alternator perform well enough the generator will come out.

I regularly charge my E450 motorhome's 230 AH AGM coach battery bank by idling it's V10 to spin the stock 130 amp alternator. Since AGM batteries also charge faster than liquid acid batteries, this idling charge method only takes a relatively short time. HOWEVER - I do wish that I had dual alternators for critical equipment redundancy!

[brianjw]

pnichols wrote:
Let me chime in here with some thoughts:

1. Large and reliable alternators will probably become more important as lithium coach batteries become more common in motorhomes. Supposedly lithium battery banks charge fast - but only if one has a charging method that can deliver the high currents that the batteries will accept. For dry camping - especially when many hours of enough solar aren't available - a large capacity alternator driven by an idling chassis engine might be very useful.

2. Since any vehicle's alternator is very important, having two on board - when one or the other is getting used a lot for high current lithium coach battery charging year after year - to me would be a necessity for equipment backup purposes should one or the other fail when drycamping. Always have a Plan B for critical Plan A failures!

P.S. I think that emergency service vehicles often have dual alternators.

Exactly this, thank you. Most ambulances around here are privately owned ragged out rigs. The company I work for has switched to a lot of transits for new rigs (or HD commercial trucks) so I haven’t seen new 7.3L gas ambulances around here yet. Maybe I need to head over to a ford truck forum and see if I can find a VIN that works.

[brianjw]

It was the Ford dealer parts dept, they’ve historically been awful.

I’m not concerned about warranty, the second alternator wouldn’t be integrated into factory electronics at all. I’ve modified everything I’ve ever owned.

I’m going to run a 400 amp hour lithium battery setup. I want to be able to run the roof top AC off of the Victron inverter while driving (or just quickly recharge the batteries while driving). The plan is to run a 60 amp sterling B2B charger off of each alternator, for a combined 120 amps to the lithium battery bank. I don’t want to overwork/overheat a smaller single alternator asking too much from it, and this seems like the safest way to do it. A little overkill, sure. No, I don’t want to have to rely on the generator while I’m driving. In fact if the solar and alternator perform well enough the generator will come out.