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We install the Nations aux 12V alternator, which provides up to 260 amps dedicated power to charge the house battery. The last rig we built Sprinter) has a 1000Ah lithium house battery and a Kingtec 12V air conditioner, which draws less than 45 amps on high. We believe this is currently the perfect set up for a climate controlled off-grid van.
 

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This Thread inspired us to revisit the 12v verses 48v issue and, in particular, to assess what it would take to convert our 12 volt system to 48 volts.

It appears that Magnum/Sensata makes a direct 48 volt replacement for our MS2812 inverter/charger and that 48 volt second alternators are available. And we could probably reconfigure our 3 x 270 watt Kyocera solar panels for series operation (and stay within the 96amp/150volt limitation of our MidNite Solar Classic controller). But we are stumbling on the battery.

One of the advantages of a 48 volt system is the use of Lithium NMC chemistry that provides about twice the energy density compared to LiFePO4. But we haven't been able to locate a vendor of such cells. Anyone have more success? Found a supplier?
A friend who purchased hybrid car batteries from a wrecked auto is working on reconfiguring to 52 Volts (48V nominal). Looking at the four modules of 21 batteries each, I’d say that volume density is probably as important to consider as weight density. One car provided around 7.7 kWh (going from memory so please don’t quote me) and they probably will take up almost as much space as lead batteries. I’m mentally comparing to +/- 12 kWh golf cart batteries that fit under golf cart seat (8 batteries at 1.5 kWh each). Weight is a lot less — a little under 200 pounds versus 500 pounds for batteries, not including racks or enclosures to mount under van floor.
 

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I have also been researching a 48v alternator, only one I can find is from American power systems. Check out their website, on the website they have a picture that is exactly like the Volta system. I’m curious if they supply Volta with the alternator.
Yes they do. They also supply us with 48 volt alternators for projects.

APS also re-sells the 24 volt version of the volta + their 24 volt alternator as their own product combo.

Just be prepared for dealing with 160 amps @ that voltage. If your battery bank is much smaller than 8 kW, it will fail from charging too fast. Strip away the hype and plan for C/2 charge rates. Adjust your alternator / battery decisions around this concept - not 1 C charging power.

There was an RV company in Canada that designed in the Volta system and forced them into providing too small of battery pack for aesthetic vs technical reasons. It just could not handle that much charging power.

On the sprinter platform, those are at the absolute mechanical limits of the engine and mounting system. In some applications, they are known for having so much torque load that alternators can be torn off of the mounts. It is a solid set up, but not for those on a budget. Substantially more expensive than a nations alternator setup.
 

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A friend who purchased hybrid car batteries from a wrecked auto is working on reconfiguring to 52 Volts (48V nominal). Looking at the four modules of 21 batteries each, I’d say that volume density is probably as important to consider as weight density. One car provided around 7.7 kWh (going from memory so please don’t quote me) and they probably will take up almost as much space as lead batteries. I’m mentally comparing to +/- 12 kWh golf cart batteries that fit under golf cart seat (8 batteries at 1.5 kWh each). Weight is a lot less — a little under 200 pounds versus 500 pounds for batteries, not including racks or enclosures to mount under van floor.
My older son built up a nominal 48 volt system from used Tesla modules a few years ago. It was a substantial portion of a model S pack. Used it to power a mobile kitchen trailer / restaurant. Pure electric set up including air conditioning, cooking, etc. Typical power draw was in the 4 - 8 kW range.

IMHO, the biggest thing that people over look when using used Tesla modules is the impact of cooling on charge / discharge rates. Without the liquid cooling system, heat removal rates are MUCH lower. Without sufficient data to guide us, we conservatively used C/10 - C/20 rates in the design.
 

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The Ford units he purchased are air cooled, and in an RV application will have low C discharge rates (or charge rate for that matter) relative to max capacity. Heat build up from current should be minimal even if running 2 A/Cs at once, or one A/C and microwave, etc.

They look like this, although he did not get them from this company.

67E514AE-EC87-4954-8110-BA000B63178D.jpeg
 

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Discussion Starter #46
I decided to go with the Volta bundle installed by Future Solutions in Elkhart IN. I am in Elkhart now and will pick up the van late afternoon. I was a little lucky, they had a full system that an OEM decided not to use. Downside, very expensive, Upside, All of the advantages listed by Chance in a previous post. The bundle comes with the 48 volt alternator and auto-start with high idle when the pack drops below 35% charge. Ability to run AC all night without charging. etc etc.
 

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Hi Kevin

What was the total” costs for such setups? What I mean by “total” is entire charging system & batteries & all equipment needed between.

I read earlier with some posts $50k $15k. Wondering what the system you picked was?
 

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Discussion Starter #48
Hi Kevin

What was the total” costs for such setups? What I mean by “total” is entire charging system & batteries & all equipment needed between.

I read earlier with some posts $50k $15k. Wondering what the system you picked was?
Total cost all-in, $25k, as a comparison, a some what similar 12 volt system from Battleborn/Victron and a Nations 2nd alternator was over $15,000 and approaching $20k with install.
 

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Total cost all-in, $25k, as a comparison, a some what similar 12 volt system from Battleborn/Victron and a Nations 2nd alternator was over $15,000 and approaching $20k with install.
Wowza. I'm a huge fan of using lithium but holy smokes, that's some moolah! What size battery did you get as Volta has different size packs.
 

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Discussion Starter #53
Pictures of the volta install. Volta Install. As you see from the pictures, I am very early in the build, Windows are in, Foam is sprayed (not well) and initial framing is started. the Volta was the big investment. additional context for the pictures. I am building out the internal cabinets and framing in 80/20 (1 inch). The battery pack is on the bottom and the other components above the pack. I will be making the frame that the inverter/converter i sitting in a bench seat facing the driver's seat. The little red button next tp the steering wheel is the auto-start.

I should start a separate build post. a quick summary, My goal is to build a van that can travel/boondock only needing water and gas and run all appliances for 8 hours off of battery. I have already installed the espar petrol heater. Everything else will run off electric including an induction cook top. I have a C-Head composting toilet. Other semi-unique goals of the build are a recirculating shower and pass-thru shower from bed to kitchen. (see Snow and Curt youtube). 8020 for all internal framing. Front dining area with swivel seats and lagun table.

If I was to buy a campervan it would be a Travato GL. I am hoping to build for $30 to $40k cheaper and eliminate the items I don't like in the travato, primarily propane, blacktank, no real "garage" storage as well as add a recirculating shower. I give Winnebago credit that they continue to improve the travato with insulation and other adds.
 
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