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Discussion Starter #1
The 48-Volt electrical system many of us have been waiting to see is finally coming our way in the 2019 gasoline Pentastar V6 as standard mild hybrid, and optional on V8s.

This could very easily be the answer to our RVing interest in high-capacity alternators without spending a lot of cash on aftermarket equipment. I haven't seen the specifications on this yet, but bet that if the system can be modified (controlled) to charge 48-Volt house batteries, it will supply all the power anyone can reasonably need to charge high-capacity lithium banks in a short amount of time.

Let's hope the system makes it into the PM shortly, which could also help with drivability.
 

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high current charging, even on lithium isn't really that good for your batteries in the long run so a 48V system is appealing as the same amount of power is 1/4 the current. However it complicates existing DC 12V appliances. Sure you can get DC to DC converters, but at that point you may as well just wire the entire van for AC and just run everything off an inverter. 48V inverters are more efficient so you aren't taking that much of a hit on efficiency. Curious to see where this goes.
 

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There are also 48v high-efficiency mini-split AC/heat-pump units available. And 48v compressors for the refrigerators. I was looking into 48v as my default DC voltage for quite a while.
 

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Discussion Starter #4
high current charging, even on lithium isn't really that good for your batteries in the long run .....cut......

I'm not sure what you mean by "high current charging" (magnitude wise), but as future RVs make use of greater lithium battery bank capacity, present 12-Volt alternators are just way too small for a quick charge.

For example, I was looking at specs on Lithionics 150-Amp 48-Volt module (7.2 KWh of capacity, equivalent to 600Ah at 12 Volts) and it states 300 Amps of maximum continuous charge rate. That's 1,200 Amps in 12-Volt equivalent. Even if charged at only 100 Amps, it's more than normal 12-Volt alternators can put out.

Regarding 12-Volt power users in an RV, what exactly "must" use 12 Volts? Not really much. Most high-powered devices will need 115-Volt AC power anyway, so it makes sense to me to use 48-Volts for most loads and then step down a small portion of that to 12-Volts to keep a small 12-Volt battery charged. In time 12-Volt DC devices will convert to 48-Volts. I think it will be quick once demand starts to shift to 48-Volts. I'd bet major equipment manufacturers like those that make DC refrigerators are already working on new 48-Volt models.
 

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I'm not sure what you mean by "high current charging" (magnitude wise), but as future RVs make use of greater lithium battery bank capacity, present 12-Volt alternators are just way too small for a quick charge.

For example, I was looking at specs on Lithionics 150-Amp 48-Volt module (7.2 KWh of capacity, equivalent to 600Ah at 12 Volts) and it states 300 Amps of maximum continuous charge rate. That's 1,200 Amps in 12-Volt equivalent. Even if charged at only 100 Amps, it's more than normal 12-Volt alternators can put out.

Regarding 12-Volt power users in an RV, what exactly "must" use 12 Volts? Not really much. Most high-powered devices will need 115-Volt AC power anyway, so it makes sense to me to use 48-Volts for most loads and then step down a small portion of that to 12-Volts to keep a small 12-Volt battery charged. In time 12-Volt DC devices will convert to 48-Volts. I think it will be quick once demand starts to shift to 48-Volts. I'd bet major equipment manufacturers like those that make DC refrigerators are already working on new 48-Volt models.
Well what I was getting at is lithium CAN be charged at super fast currents (my 400ah bank can max continuously charge at 800 amps) but they usually recommend charge speeds to about 1/3 of the capacity of the battery so in my case around 132 amps to keep the battery healthy for longer. While my stock alternator isn't going to cut it for that amount of current for very long, a beefier second alternator could.

As for 12V in an RV you typically have water pumps, water heater controls, forced air controls, lights, fridges (though some 12V models can also run on 120ac), usb ports, ect. I think it's still a little soon for them to adapt to 48V but who knows. But you are correct that getting a DC-DC converter to step down to 12V isn't that big of a deal for the devices I mentioned above. However it'll be a while before we'll see 48V in many vans.
 

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Discussion Starter #6 (Edited)
Granted not all lithium battery chemistries are the same, but I found it very interesting that the battery FCA will be using in the RAM mild-hybrid pickup is tiny by comparison to RV house batteries, yet it will be called upon to charge and discharge at very high rates during vehicle acceleration and deceleration.

"330 watt-hour lithium-ion Nickel Manganese Cobalt (NMC)-Graphite battery."


http://media.fcanorthamerica.com/newsrelease.do?id=18758&mid=1


Added torque of 90 or 130 lb-ft is also interesting in that I suspect it's measured at engine shaft after belt reduction, but would still imply a lot of power coming from motor and tiny battery. I've read estimates of 12 to 16 added horsepower, but can't quite figure those low numbers.
 

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I am surprised they don't look to putting the electric drive on the rear wheels - more room for a bigger motor and the benefit of AWD.
 

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Discussion Starter #8
What you guys are referring to would be quite a bit more than the mild hybrid of the RAM pickup, and probably much closer to a "real" hybrid like the Pacifica's. I'm fairly certain that a 90 HP motor would be too large to power at 48 Volts.

Installing a motor/generator between rear wheels to make it not only a hybrid but also AWD would be a nice option to have. Not only would it improve acceleration and hill climbing, but also fuel economy and traction on snow/ice and dirt. Cost would be much much higher though than simple 48-Volt mild hybrid.


Taking electrical power off a normal hybrid system at much higher voltages to power a house battery bank may be doable, but likely beyond what most of us should attempt as a DIY project for numerous reasons (safety, warranty, etc.). I think it's very possible as Ford announced that they are planning an F-150 hybrid pickup with capability to power contractors' tools on job site. GM may have done similar but with smaller inverter.


Regardless, I'm very interested in any PM powertrain changes that may be coming for 2019. I've been following the 2018 diesel thread, but I'm more interested in gasoline engine and what transmission FCA will upgrade to. Any hybrid option would suggest a possible upgrade similar to that of the Pacifica.
 

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Discussion Starter #10
It's a very different type of system, but I'm glad Winnebago made the jump to 48-Volts rather than stay with 12-Volts.


What will be be interesting in my opinion will be if (or when) ProMasters get a 48-Volt mild hybrid system like those in pickups, whether RV manufacturers like Winnebago will still have to add a second alternator, or if they will be able to piggyback off the OEM's 48-Volt alternator.

The OEM 48-Volt alternator also serves as a starter, and while it can produce even more power than the Volta 48-Volt alternator, it "may" not have the duty cycle for a much larger battery. I think the Travato's battery is about 20 times larger than the one in RAM pickups. Controls of vehicle hybrid system may also get too complicated if a much larger "house" battery is added in parallel. With any luck it may just take new software, but who knows. Regardless, it's all great news to me since we are moving in right direction.
 

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Discussion Starter #12
Steve, pictures of the 48-Volt alternator for RAM V6 pickups look too tall to fit under PM hood in my opinion. I'd guess FCA will have to first repackage, or wait until they replace PM engine and/or update PM front end.

With Mercedes going to turbo 4-cyl in Sprinter as gasoline option, it wouldn't surprise me if FCA does the same. In that case the 48-Volt motor/alternator could supply additional torque when needed. A 4-cyl turbo with mild hybrid assist should exceed V6 torque output. Granted, more complicated. :(
 

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I'm glad I read this thread. I am visiting a van conversion shop next week to build my next campervan. I was ready to put a non-refundable deposit to hold a production spot and the volta 48 volt lithium system was one of my requirements.......but with a 48 volt Promaster in the future I should wait till I learn about the availability.

I'm planning to sell my diesel 4x4 sprinter to get a fwd, lower, gasoline van. The hybrid would be the best of both worlds.
 

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Some people here have been waiting four years for the "new" updated Promaster nose before they order theirs! Just a warning;)
 

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Discussion Starter #15
Some people here have been waiting four years for the "new" updated Promaster nose before they order theirs! Just a warning;)

Very true; although in my case I’ve been waiting for a newer automatic transmission as well, which I find even more important. :)

In the mean time I had to spend a ton on my existing van to keep it reliable for traveling, but it’s cost less than depreciation on a new van anyway, so not a complete loss.
 

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Discussion Starter #16
The 48 Volt Travato has arrived.
Here’s the detailed review James of The Fit RV promised. It has a lot of very good information worth reading, including references on how this system can make solar pointless for many van campers.


https://www.thefitrv.com/rv-reviews/our-experience-as-pure3-lithium-travato-test-pilots/


As an engineer, I’ve mentioned a few times that I’d prefer a high-capacity alternator from the chassis manufacturer, and sure enough they had problems with the prototype’s belt drive after a couple of days. The engineering resources and expertise of companies like Ford or FCA on their engines in this area are hard to replicate. Even if that’s not an issue, the cost should be a fraction of aftermarket costs.
 
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