Dual alternator kit for the Ram Promaster announced

markopolo · 02-01-2015, 09:35 PM

Nations Starter & Alternator has put a photo of their dual alternator kit for the Ram Promaster on their Facebook page: https://www.facebook.com/permalink.p...d=147260728552

Quote:

Attention Dodge Promaster owners and Customizers! That are looking to convert your vehicle to a engine driven generator we have the first dual alternator kit on the market! This can give you the flexibility to have a mobile electrical supply- The possibilities are endless!

http://www.nationsstarteralternator.com

wincrasher · 02-01-2015, 10:27 PM

Holy crap!

198 amps at idle!

http://www.nationsstarteralternator....-3.6-270xp.htm

booster · 02-01-2015, 10:50 PM

That may not be the alternator they are using, as it is the one for the van itself. With a separate mount, they can use one of the dedicated ones, probably from DC Engineering, but could be other. They can get huge specs out of them at idle because they can spin them as fast as they want and use an internal regulator if they chose.

stanw909 · 02-02-2015, 12:58 AM

So what is the amp limit at idle and what will it run?

markopolo · 02-02-2015, 12:56 PM

There's not enough info to know. If they use the high amp alternator then the specs give an idea of what to expect.

Idle Amperage 180
Hot Idle Amperage 165

Booster previously posted the DC Power Engineering link: https://www.dcpowerinc.com/fit/Chrys...formance_sheet

The "average" idle of 198A was at around 2,250 alternator shaft rpm. 3 or 3.5 to 1 ratio is noted. (alternator shaft / engine)

You'd need to know the exact ratio used in the end setup.

There should be enough DC amps there to run an AC air conditioner through an inverter though assuming adequate wiring etc.

gerrym51 · 02-02-2015, 05:05 PM

I actually think this is a misnommer. there is no doubt that the extra alternator helps recharge the battery faster. however the air conditioner runs off the battery and inverter. it is not a direct power transfer from the alternator to the inverter. because battery charging is not 100 percent efficient(far from it) a bettery pack running the AC would gradually decrease eve en if the xtra alternator system is pushing amps at it.

markopolo · 02-02-2015, 05:23 PM

The inverter will use power directly from the alternator and yes a battery(ies) need to be in the mix.

Booster's test setup showed his system held 13.7v while running the microwave: http://www.classbforum.com/phpBB2/vi...hp?f=12&t=3115

A fully charged battery is only 12.7v or 12.8v. Booster's system holding at 13.7v means that the alternator was supplying all the current needed.

I could hold 12.9v when running the microwave oven in my van with an old stock alternator: http://www.classbforum.com/phpBB2/vi...&t=2668#p15768

Davydd · 02-02-2015, 06:02 PM

The Advanced RV M-B Sprinter second alternator charges batteries with DC current and the inverter in turn draws from the batteries to change to AC power. I don't think their is any direct to inverter current. The reason for the second alternator is the engine alternator is tied into M-B's sophisticated computer system that can't be diddled with. The computer controls that alternator and would not always be compatible with house needs. So, the second alternator is independent and works with the Silverleaf system. Of course you'll get more capacity and higher current with it for faster charging as a benefit.

markopolo · 02-02-2015, 06:08 PM

If wires from the alternator bolt to the batteries and wires from the same batteries bolt to the inverter then there's direct linkage. Current will flow along the path of least resistance.

booster · 02-02-2015, 06:12 PM

If there is no direct to the inverter from the alternator, I would think you would need a massive 12v to 12v battery charger, and the charge from it would still need to be connected to the batteries, and thus the inverter. Maybe I am missing something.

When the ARV is on shore power, does the air conditioner still run off the inverter, or is there a transfer switch to the shore 110v? I think someone here said that the Roadtreks don't use the transfer switch, but that might have been only for generators.

gerrym51 · 02-02-2015, 06:23 PM

Quote:

Originally Posted by booster

If there is no direct to the inverter from the alternator, I would think you would need a massive 12v to 12v battery charger, and the charge from it would still need to be connected to the batteries, and thus the inverter. Maybe I am missing something.

When the ARV is on shore power, does the air conditioner still run off the inverter, or is there a transfer switch to the shore 110v? I think someone here said that the Roadtreks don't use the transfer switch, but that might have been only for generators.

booster- roadtreks bigger inverter models 2500 and up require always running thru inverter. jim hammill has said this is because it guarantees the power protction parts of the inverter/charger will be used. this is how they can warraty everything in the e-trek fro 6 years at least thats what he said

Mark sort of implied that your system feds inverter directly

markopolo · 02-02-2015, 06:36 PM

I don't see how you're missing anything Booster. You'd need to dump the alternator current somewhere for it to not be used. The common linkage point would be at the battery terminal bolts. Current following the path of least resistance does the rest.

100% sure in my van (and Booster's) that alternator current is directly used when running things off the inverter. Engine running of course

It's very simple to know - just look at the system voltage when the load is on. If the voltage is higher than a fully charged battery's voltage then both the volts and the amps are being supplied by the alternator.

Another example is that I run my fridge off the inverter while driving. System voltage - shown at the inverter - is around 13.8v or 13.9v. The alternator is supplying all of (and more) current than what is needed by the fridge heating element (absorption fridge).

booster · 02-02-2015, 06:42 PM

Quote:

Originally Posted by gerrym51

Quote:

Originally Posted by booster

If there is no direct to the inverter from the alternator, I would think you would need a massive 12v to 12v battery charger, and the charge from it would still need to be connected to the batteries, and thus the inverter. Maybe I am missing something.

When the ARV is on shore power, does the air conditioner still run off the inverter, or is there a transfer switch to the shore 110v? I think someone here said that the Roadtreks don't use the transfer switch, but that might have been only for generators.

booster- roadtreks bigger inverter models 2500 and up require always running thru inverter. jim hammill has said this is because it guarantees the power protction parts of the inverter/charger will be used. this is how they can warraty everything in the e-trek fro 6 years at least thats what he said

Mark sort of implied that your system feds inverter directly

Yep, mine is straight off the alternator to batteries which are also connected to the inverter. My charger and inverter are not combined, but stand alone.

Are all of the big inverters in Roadtreks inverter/chargers? If so, they may have an internal transfer switch for the 110v and just condition the power, like Tripplite does. Otherwise turning 110v AC into 100+ amps of DC 12v and then inverting it back to 110v AC again would generate an awful lot of heat, I would think.

Davydd · 02-02-2015, 06:45 PM

On the Advanced RV there is a 4/0 AWG wire that runs from the alternator straight back to the battery bank nearly the full length of the van. That is a huge wire. I'm plugged into shore power right now and the inverter is off.

booster · 02-02-2015, 06:55 PM

I just looked at what I think is the etrek inverter/charger, and it does have a built in transfer switch for the AC power, so they aren't doing a double convert/invert procedure, it would appear.

That wouldn't change the fact that the 12v output of the inverter/charger would go to the batteries and inverter, as would the alternator I would think.

http://zlpower.en.made-in-china.com/...0-LW6000-.html

markopolo · 02-02-2015, 07:39 PM

Quote:

Originally Posted by gerrym51

I actually think this is a misnommer. there is no doubt that the extra alternator helps recharge the battery faster. however the air conditioner runs off the battery and inverter. it is not a direct power transfer from the alternator to the inverter. because battery charging is not 100 percent efficient(far from it) a battery pack running the AC would gradually decrease even if the xtra alternator system is pushing amps at it.

I know for sure that there's "direct power transfer from the alternator to the inverter" in my RV.

And I know for sure that the alternator in my van supplies way more current than what the 110v air conditioner needs. The old alternator in my van supplies enough current to simultaneously run the A/C off the inverter and also charge the batteries and run lights etc. (small a/c

)

Diesel fuel would be a limiting factor - my A/C would probably only run for an hour or so after I run out of diesel

I think I know what you're getting at though. Lot's of vans have relatively small wiring and fuses on the wire from the alternator to the battery bank. Take the example of an RV with a 50 amp fuse on that wire. At most you'd get 50 amps from the alternator to the inverter via the battery terminals. In that case, you would deplete the batteries even with the engine running.

Ask Roadtrek if their setup allows alternator current to get to the inverter and let us know what they say

--------------------------------------------------------------------------------------------------------------------------------------------------
Notes:

Hot Idle Amperage 165 - from Nations
165 amps x 14 volts = 2,310 watts
165 amps x 13 volts = 2,145 watts

Boxster1971 · 02-02-2015, 07:56 PM

The new Magnum hybrid inverter/Chargers will boost the shore power for heavy loads.

- - Mike
2013 AS Interstate on 2012 MB Sprinter 3500 Long & Tall

gerrym51 · 02-02-2015, 08:21 PM

as i've said-the zion comes standard with the inverter and special battery.

so in effect you already have 2/3 of the engine generator system standard. since the battery is only 186 amps it seems th xtra alternator is overkill

if i could get 2 of thse batteries i might change my opinion.

by getting the onan i believe i'm getting in effect both systems.

wife says cats have to be guaranteed protection-i obey

wincrasher · 02-03-2015, 02:15 PM

Maybe this sounds idiodic, but bear with me.

If you were going to buy this dual alternator kit to retrofit a van like mine, what else would you need?

Would you just need to replace the Onan with an inverter? What about this cooling of the alternator that's been mentioned?

gerrym51 · 02-03-2015, 02:40 PM

Quote:

Originally Posted by wincrasher

Maybe this sounds idiodic, but bear with me.

If you were going to buy this dual alternator kit to retrofit a van like mine, what else would you need?

Would you just need to replace the Onan with an inverter? What about this cooling of the alternator that's been mentioned?

add battery capacity,put in inverter,put in 2nd alternator,improve wiring. unless you need the space for more batteries-keep the onan-you can have both

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