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I would like to build out a 48 volt system. Volta uses a 58 volt alternator, their part number is 160GM92V-58. Can this be purchased separately? or other alternatives?

Thank you
Kevin
 

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If you have a diesel, be aware that as far as I have been able to determine nobody has a second alternator kit for the diesel, only the gas engine.
I have friends who have a gasser with a second alternator, and the second alternator is pretty much at the bottom of the engine, somewhat protected by a skid plate.
Please keep us posted about your progress!
 

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I don’t remember the details, but there are several threads on this forum of the second alternator installation causing the belt to wear and break. There’s an easy fix, then no more of this issue. I believe the member Winston was the first.
 

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I’d love to have a 48V system feeding my NH house off grid. I max out at 125 KWH a month there including a one ton split A/C. I’d need a 3000 Watt PSW 48-220 Volt inverter capable of continuous service and something like 200 A-H battery set @ 48V, 1,000-1,200 watts of solar panels to feed it, and a good propane powered generator set to emergency charge. I am seeing van builders approaching this level of infrastructure. I have to ask myself why? My van system has lots more capacity than I need. Could I manage to use more. I guess so but as green as it may be to power anthing off grid it still seems to me to be more than a camping rig needs. I suggest a good energy audit prior to spending and installing such large systems. If you find you need it go for it.
That being said I know of one member with about 600+ watts of solar, lithium set, second generator, and a big inverter. who has to plug in at campgrounds. They don’t have A/C either!
 
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Humans do things because they want to and can. Especially in modern culture.
All the "reasons" and justifications are just some psychological crap that's embedded in our DNA.
There's a word for it but I can't remember it.
 

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The way I oriented the new house, the gable ends face N & S.
So, solar panels on the roof would face the morning and/or evening sky.
I thought of almost everything, but future solar or greenhouse attached to the house were 2 things I couldn't accommodate in the design.
So, detached greenhouse and solar on the ground if I want it facing south.
Which might be better for maint anyway.
Definitely investing in a propane generator at some point.
As for the 48v system in a van, I wonder if they make some type of unit that would step up the voltage from the alt, as opposed to adding a second alt.
 

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I bought the land slopping south, built the house at an angle to the town’s road so the front roof face is 40º (10 pitch) and directly geographic south for a reason. I cut 2.5 acres of trees as well. If ever there was a perfect site for solar in southern NH I got it!
 

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Amazingly with panels as low as $.75 per watt, FLA batteries at $90 for 215 amp hours @ 6 volts and a quality inverter at ~$600 and a generator set at $1000 I could do the instal myself for about $4,000 with a payback of 5 years! Having lived for 10 years earlier with a wind plant off grid I hesitate to run an electric company again, although I do run one in my van. Solar is magic unlike a Dunlite windmill on top of a tower so maybe ..............
 

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Now, if you only had a spare $4000 laying about! Just think of all the things you could buy with it?
 

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Discussion Starter #11
If you have a diesel, be aware that as far as I have been able to determine nobody has a second alternator kit for the diesel, only the gas engine.
I have friends who have a gasser with a second alternator, and the second alternator is pretty much at the bottom of the engine, somewhat protected by a skid plate.
Please keep us posted about your progress!
2019 3500 Gas. One of the reasons I purchased a gas. Although, No more Diesels.
 

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Just spent that $4000 on an old Tacoma 4WD so Jack and I will have the ultimate American experience- A Man, his Dog, and a pickup truck. Solar is so less important!
 
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On da road with RD & Jack - playing in theaters near you next summer
 

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The need for 48 VDC electrical and solar are kind of at opposite poles. We can easily argue that the more you need a 48-Volt (nominal) second alternator, the less you benefit from solar.

Likewise, those who can meet their needs from solar are using so little energy (relatively speaking) that going to expense of a second after-market alternator, particularly a 48 VDC unit, makes little sense. It all depends on your energy needs.

From my perspective, the main reason to add a second after-market alternator is to make running an air conditioner for multiple hours from batteries possible; and especially if it will run all night.

If using over 5 kWh or more of battery energy at a time to power an A/C for many hours, solar won’t be nearly enough. And if trying to recharge batteries back in only 1 to 2 hours of driving (or idling), then you need some serious alternator capacity. That’s when 48 VDC makes most sense.


A second OEM alternator is such a great deal that I hope my next camper will have one. Even though it’s at 12 VDC nominal, having 400 ~ 500 total Amps for well under $1,000 is a bargain in my opinion.
 

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I agree, Chance. We only recommend an aux alternator (Nations) when the client chooses a DC air conditioner for their build. If no air conditioner then no need for an aux alternator. We can handle all other loads by simply increasing the size of LiFePo4 battery.
 

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Hi, yes we build van electrical systems with 48 volts routinely. The second alternator can be 12 or 48 volts. If it is 48 volts life is easier but it can be done either way. I have done a 48 volt alternator on a promaster yet.

More or less the setup is so that the solar can run the refrigerator and lighter loads. The alternator runs the serious power loads.

What I see is that anytime a customer has a system that depends on only one method of charging, it just doesn't work out. Regardless of what they believe is true when we talk about it, life just doesn't work out that way.

Once you have a serious power system in a van, adding solar doesn't add all that much cost.

Regardless of the DC voltage, a Li based battery pack should be sized to stay at or below C/2, so a 5 kW charging system really needs ~ 10 kW-hrs of battery pack to be within the mfg recommendations.

Most of the issues that happened in the RV industry 48 volt implementations were due to not accepting this reality.
 

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I’d love to have a 48V system feeding my NH house off grid. I max out at 125 KWH a month there including a one ton split A/C. I’d need a 3000 Watt PSW 48-220 Volt inverter capable of continuous service and something like 200 A-H battery set @ 48V, 1,000-1,200 watts of solar panels to feed it, and a good propane powered generator set to emergency charge. I am seeing van builders approaching this level of infrastructure. I have to ask myself why? My van system has lots more capacity than I need. Could I manage to use more. I guess so but as green as it may be to power anthing off grid it still seems to me to be more than a camping rig needs. I suggest a good energy audit prior to spending and installing such large systems. If you find you need it go for it.
That being said I know of one member with about 600+ watts of solar, lithium set, second generator, and a big inverter. who has to plug in at campgrounds. They don’t have A/C either!
If your off grid home is set up completely as 120 vac, then the need for the transformer to make the split phase is eliminated.

There are some inverters that allow for bonding the neutrals together in a master / slave arrangement. The combination produces 240 vac split phase directly.

For the system that you are describing, 800 amp-hrs of AGM battery back is what I would use so that you don't have to worry about when it gets cold.

I have built systems like that for a Tiny house. It was built inside of a 26 ft box truck. Pretty interesting project.
 

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I have a 220 volt deep well pump (1/2 Hp) and my 220 volt 1200 btu split A/C I would want to run in summer days. My peak amperage draw might be 30 amps when the pump starts. As I have a generator interconnect mechanical toggle already added to my main disconnect I could feed the 220 AC into that through a 50 Amp breaker leaving the power company lock-out intact with the option of switching two breakers controlled by the lock out hardware returning to the power company. No special wiring, safe, code compliant, and optioned for either. My needs are so small, like an RV or tiny house, grid tie is impractical due to the exorbitant service fees for power. I tend to use $14 of electricity but the bill is $60. Fees, fees, fees!
Thanks for your thoughts and I responded as I think what I might do is not that far from the larger RV world and where it is going.
 

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Discussion Starter #19
Hi, yes we build van electrical systems with 48 volts routinely. The second alternator can be 12 or 48 volts. If it is 48 volts life is easier but it can be done either way. I have done a 48 volt alternator on a promaster yet.

More or less the setup is so that the solar can run the refrigerator and lighter loads. The alternator runs the serious power loads.

What I see is that anytime a customer has a system that depends on only one method of charging, it just doesn't work out. Regardless of what they believe is true when we talk about it, life just doesn't work out that way.

Once you have a serious power system in a van, adding solar doesn't add all that much cost.

Regardless of the DC voltage, a Li based battery pack should be sized to stay at or below C/2, so a 5 kW charging system really needs ~ 10 kW-hrs of battery pack to be within the mfg recommendations.

Most of the issues that happened in the RV industry 48 volt implementations were due to not accepting this reality.
Harry, Thank you, How can I source a 48 volt 2nd alternator for a promaster 3500?
 

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Harry, Thank you, How can I source a 48 volt 2nd alternator for a promaster 3500?
Hi Kevin, 48 volt systems engineering is a real journey. The reasons are:
  • Almost none of the 48 volt off grid home equipment is designed for mobile use (stationary only)
  • 0% of the commonly used blue sea marine components that people like to use in van electrical system are 48 volt compatible.
  • The relatively few people who have pioneered into this area have spent so much time and money on the parts selection, testing, and engineering that they are mostly just selling "systems" and not really talking in detail about how they pulled it off.
  • We might be doing it routinely, but that is the result of several years of effort.
On the other hand, 24 volt systems are relatively easy to implement:
  • There are many components from the heavy truck and marine market that are readily obtainable.
  • A number of companies make 24 volt alternators in various sizes and form factors
  • 24 volt heaters, refrigerators, fans, etc are commonly available
If you compare a 12 volt vs 48 volt system, a 24 volt system provides ~ 75% of the benefits of moving up in voltage with only 25% of the head aches.

I guess my point is that unless you are already very experienced with 48 volt system in a mobile environment, strongly consider to use 24 volts instead.

We build "drop in electrical systems" that are built with both 24 and 48 volt battery packs, etc, but I only provide advice to customers who have purchased our systems. It is just too easy for people to get in over their heads on a 48 volt setup.
 
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