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2016 136WB low roof diesel, converted to an RV by Sportsmobile, TX
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Discussion Starter #1
Does anybody have an advice on where to get either brackets for a second alternator or a replacement alternator with 12V and 24V outputs for the ecodiesel?

I am working on an RV conversion, and had already bought the batteries and invertor when I found out that my source for a second alternator kit did NOT have such a kit for the eco-diesel. Since the batteries and inverter are 24V systems, I cannot just use a battery isolator and the stock alternator.

So my choices are either to find a source for a second alternator mount, or to find a replacement alternator that will fit where the stock alternator goes and will make 12V and 24V.

Any help appreciated.
 

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http://www.sterling-power-usa.com/SterlingPower12volt-24volt50ampdcinputbatterytobatterycharger.aspx

There are many different flavors of twelve to twenty four volt charge controllers - and come cheaper than one-off buying aux alternator brackets, pulleys and alt head.

These can come in handy for large trailer & tow vehicle combinations to transmit charging power the twenty-plus feet to even reach the trailer then the additional ten, twenty or more feet to reach the trailer battery without having to have cable as thick as your wrist to prevent 12V nominal voltage dropping to useless levels from wire resistance.
 

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2016 136WB low roof diesel, converted to an RV by Sportsmobile, TX
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Discussion Starter #3
Thanks for the information, and that may be my fallback.

The problem is that with a 300Ah battery system, 50A is going to take 6 hours to charge the batteries fully. If I've run the batteries down overnight, that's a full day's driving to charge them back up. That's where I'd like a bit more charging current.
 

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You might want to keep the drain to 1/2 the battery capacity= 150 Ah. That will refill the battery in 3 hours. 150 Ah is 15 amps for 10 hours. That is a lot of electrical power. What are you running? I know people living off-the-grid who live in 3 bedroom houses that don't use that much power! It is partly about controlling your use in a van. I want to help but I am having a hard time understanding what you will do with the power?
 

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2016 136WB low roof diesel, converted to an RV by Sportsmobile, TX
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Discussion Starter #5 (Edited)
I'm running LiFeMnPO4 batteries, and the 80% maximum depth of discharge for maximum life is factored in already.
And remember that's 300Ah at 24V - or 60Ah at 120V. Running an air conditioner is roughly 10A at 120V, so that much battery is only 6 hours of AC. Add in running things like a microwave, an electric rangetop, and you quickly go through that much. This is an all-electric rig, no propane.
 

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I'm running LiFeMnPO4 batteries, and the 80% maximum depth of discharge for maximum life is factored in already.
And remember that's 300Ah at 24V - or 60Ah at 120V. Running an air conditioner is roughly 10A at 120V, so that much battery is only 6 hours of AC. Add in running things like a microwave, an electric rangetop, and you quickly go through that much. This is an all-electric rig, no propane.
Just curious if you found any other solution for your alternator.
 

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Master Overland Custom Vans Tampa
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Does anybody have an advice on where to get either brackets for a second alternator or a replacement alternator with 12V and 24V outputs for the ecodiesel?

I am working on an RV conversion, and had already bought the batteries and invertor when I found out that my source for a second alternator kit did NOT have such a kit for the eco-diesel. Since the batteries and inverter are 24V systems, I cannot just use a battery isolator and the stock alternator.

So my choices are either to find a source for a second alternator mount, or to find a replacement alternator that will fit where the stock alternator goes and will make 12V and 24V.

Any help appreciated.
Why choose a 24V system over standard 12V? I have 640ah LiFePO4 battery and I regularly see my stock alternator delivering over 100 amps to charge.
 

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2016 136WB low roof diesel, converted to an RV by Sportsmobile, TX
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Discussion Starter #10
Driving a 4kW inverter from 12V requires too many amps; the inverter vendor I used doesn't make a 4kW inverter in 12V; the rig is a full electric (no propane) and so running the oven, the AC, and anything else requires more than 2kW.
 

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Wow that is over 335 amps at 12 volts and more than 150 amps even at 24 volts! You are right that is a LOT of current. Even though it can be done I have to think an all electric with things like an oven, toaster, flatiron, radiant heat, big microwave, AC, and other heating appliances may be something to give serious consideration to avoiding in our small vans and finding alternatives may make more sense. You will find a solution and should share it when all is working and good but please be fortcomming about the trade offs as I know you will. Happily having gone another way and being fuzed at 50 amps I am over whelmed by what you are going through and would caution others to be aware of the issues and costs.
 

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Master Overland Custom Vans Tampa
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My van is all electric. Induction cooktop, convection microwave, radiant floor heat, 12V 600W heater, 1200W water heater, 12V A/C, etc etc. The AC appliances work great with my 2k Magnum inverter. I just don't turn on the microwave and water heater at the same time.
 

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On Sunday we stopped at an RV dealer to look at small motorhomes, and they had a Roadtrek with the optional 2nd alternator in lieu of an Onan-style generator.

It wasn't a diesel ProMaster so it wouldn't help you, but it shows the basic principle of all-electric is very viable. I eventually want to pursue the same type of design, although I'm thinking 48-Volts instead of 24-Volts.

I look forward to following your project.
 

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Our off grid home had 114 Volt DC. With 19-6 volt cells it works out great. You can use many "normal" appliances with heating elements and tools with universal motors (most) the "modern" control circuits present problems but we found that many switches and thermostaticly controlled appliances can be used if you add a capacitor to absorb the electrical surge when the points open. F rated switches work, fuses work. and the current is lower than 24. Long strings of LED lights in series would work too. When you go above about 48 volts the danger of shocks is present so 114 becomes a consideration. Welders seem to run 36-48 volts and 3 12 volt batteries and some welding rod can get your 4X4 back from the beyond. Perhaps we shoud just get a cheap 1999 Honda Insight and tow it along for power.
 

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...cut... When you go above about 48 volts the danger of shocks is present so 114 becomes a consideration. ....cut.....
That's my understanding as well.

Up to 60 Volts is considered relatively safe, so 48-Volt systems which charge at around 56 Volts is about as high as we should go in a motorhome/van project. That keeps it simpler and safer than the much higher DC voltages that hybrid and electric cars utilize.

I will personally evaluate a 48-Volt system (instead of 24 or 36) because it will likely become the next automotive electrical system standard.

For the last 20 years it looked like 36-Volt (42V charge) systems would replace the existing 12-Volt, but now it looks more like 48-Volts will be the future.


It shouldn't make much difference initially versus 12-Volt conventional systems, but since I keep vans over 10 years, I'm planning ahead thinking appliances and other stuff/equipment will be more popular in 48 than 24 or 36.
 

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Why choose a 24V system over standard 12V? I have 640ah LiFePO4 battery and I regularly see my stock alternator delivering over 100 amps to charge.
Do you know what stock alternator you have? 180 amp? I want to charge my Lithium batteries from the alternator. I'm thinking about using a Renogy battery to battery charger. They have a 20, 40, and 60 amp version. I don't know what would be the best to get. I don't know much can it charge without overheating. Do you use a battery to battery charger or a battery isolator of some sort?

 

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2016 136WB low roof diesel, converted to an RV by Sportsmobile, TX
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Discussion Starter #17
I have the 220A alternator. I have to use a DC/DC converter since my house batteries are 24V - I found a 1200W converter online; 110A in for 50A out (with conversion losses). It's a chunk of a unit.
 
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