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03-11-2019, 08:58 PM
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#21
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Senior Member
Brand: Thor Motor Coach
Model: Hurricane 31S
State: Texas
Posts: 4,157
THOR #6411
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One thing I did notice was the alternator's relatively high cut-in rpm and wondering about the high rpm capability. Fords 175 amp alternator on the V-10 has a 1,600 rpm cut-in, max of 175 amps @ 6,000 rpm and a 18,000 rpm ability. With a 3:1 pulley ratio that gives 30 amps at 800 engine rpm and only 15,600 rpm at engine red line. Volta rpm curves are 4,000 rpm cut-in and max shown of 8,000 rpm but one would hope it will stand at least 16,000 rpm; otherwise there only use will be on big diesels with limited rpm capability.
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Jim & Roy Davis
2016 Hurricane 31S
1961 Rampside in tow
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03-11-2019, 09:16 PM
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#22
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Senior Member
Brand: Thor Motor Coach
Model: THOR Chateua 35SF
State: Florida
Posts: 5,850
THOR #11130
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Quote:
Originally Posted by Chance
Other companies started using Volta a while back. I think Thor is late to game, and hardly innovative. But I do credit them for embracing the obvious need, which I hope filters down to smaller motorhomes.
Overnighting silently without a generator while running A/C is indeed a great option to have.
For smaller rigs, a single 3.6 or 4.0 kW inverter/charger is not that expensive anymore in order to produce 30 Amps. And now OEMs like Ford are starting to offer a second alternator from factory that can recharge battery bank while driving, so the main cost remains the battery bank. And it would only take 10~12 kWh to power an A/C overnight in a National Park, or in a rest area or Walmart parking lot. I’m glad to see all the pieces coming together to make an affordable system (not that Volta isn’t still expensive).
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I wasn't referring to the little van campers like Travato...I was referring to the big boys, like Thor. What other full size DP motorhome manufacturer offers this?
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Now an SOB
Traded Thor for Melbourne Prestige 24NP
2018 THOR Chateau 35SF
Two Labs, Bugsie & Blondie
Blondie passed in 2020 at 5 to Leukemia
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03-11-2019, 10:38 PM
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#23
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Senior Member
Brand: Thor Motor Coach
Model: Chateau 31L
State: Florida
Posts: 2,063
THOR #12189
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Quote:
Originally Posted by Chance
A major benefit of these systems is the ability to charge battery bank much quicker than the rate power is used later. If you can charge in 1 hour at 10 times the rate, then you can have silence (no generator) the other 9 hours. For that reason I think small generators may not be best solution.
Keep in mind large lithium battery banks can accept a lot of power — much more than small portable generators can make.
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Not to mention they have a different charge profile. The AIMs and Xantrax inverters come in pure sine, 4kw, solar charge profiles, and have built-in transfer switches.
Why no solar included in the conversation? Just curious. Too expensive?
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03-12-2019, 02:46 AM
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#24
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Senior Member
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
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Quote:
Originally Posted by Beau388
One thing I did notice was the alternator's relatively high cut-in rpm and wondering about the high rpm capability. Fords 175 amp alternator on the V-10 has a 1,600 rpm cut-in, max of 175 amps @ 6,000 rpm and a 18,000 rpm ability. With a 3:1 pulley ratio that gives 30 amps at 800 engine rpm and only 15,600 rpm at engine red line. Volta rpm curves are 4,000 rpm cut-in and max shown of 8,000 rpm but one would hope it will stand at least 16,000 rpm; otherwise there only use will be on big diesels with limited rpm capability.
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Just an educated guess based on my experience: Larger items normally can’t rotate as fast due to physical limitations. The alternator that Volta uses I expect is physically larger because it puts out a lot more power. If indeed larger, it might not be able to take 16,000 to 18,000 RPMs.
The bright side is that “if” it is physically much larger, it can then also handle more heat dissipation which means more power at steady state. That’s got to be important with alternators that make close to 10 kW or more.
Notice many of the new 48-Volt motor/generators on mild hybrid engines have external liquid cooling. The Volta I believe has air cooling, so may need to be a little larger.
Speed in itself shouldn’t be much of an issue since belt drive can provide different ratios as needed. Volta is being used on Winnebago Travato which has a high-reving DOHC V6.
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03-12-2019, 03:18 AM
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#25
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Senior Member
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
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Quote:
Originally Posted by TheBreeze
Not to mention they have a different charge profile. The AIMs and Xantrax inverters come in pure sine, 4kw, solar charge profiles, and have built-in transfer switches.
Why no solar included in the conversation? Just curious. Too expensive?
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Solar is included in new motorhome design from Thor, and was briefly mentioned above. More specs on total system is really needed. The issue I see is not so much solar being expensive, but rather that when these systems become very high in power flow, then the solar contribution becomes less important as a percentage of the total. We’ll just have to wait for all system specs.
Solar is always great to have to keep batteries charged and to power fridge during storage, etc.
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03-12-2019, 03:42 AM
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#26
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Senior Member
Brand: Thor Motor Coach
Model: 2017 Axis 25.4
State: Arkansas
Posts: 2,669
THOR #12231
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Well I think its awesome and a step in the right direction.
I can see 5 years from now .... All big RV's have a system like them... then hopefully the prices will go down enough were it will become a viable option for any RV.
Who knows..... this could be the beginning of the end for on board Gennys. Might take 10 - 15 years but its all started here.
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2017 Axis / 25.4: Big Foot Levelers, Aims 1200 Watt inverter, Ceramic Window Tint, Full River AGM 6V batteries, Front Hellwig Sway bar / Rear Track Arm, Safe T Plus Steering Stabilizer, PD 4655 converter, Hard Wired Surge Guard, WEboost + WiFi Ranger, LED Headlights/Driving lights, TPMS, Surge tank, Tornado flush, Viair Compressor
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03-12-2019, 01:10 PM
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#27
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Senior Member
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
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Quote:
Originally Posted by Long & Winding road
Well I think its awesome and a step in the right direction.
I can see 5 years from now .... All big RV's have a system like them... then hopefully the prices will go down enough were it will become a viable option for any RV.
Who knows..... this could be the beginning of the end for on board Gennys. Might take 10 - 15 years but its all started here.
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Guys have been tinkering with this concept for decades; it’s just now that costs are a little more affordable due to advances in technology and manufacturing.
About 15 years ago I went to see a camper van in Houston that was built by a start-up company. It was beautifully finished inside and exterior looked like a luxury travel van so it could avoid many HOA restrictions. I loved it but was too expensive.
They had installed 8 AGM batteries under the floor, which powered a 2,000-Watt inverter that supplied power in van. It could even power the 8,000 BTU/hr A/C for a few hours. Basically, it was a simpler version of the systems we see today.
Roadtrek produced many motorhomes with similar systems, but improved capabilities by switching to lithium batteries and adding a second dedicated alternator. However, not all went well initially. The concept was great, the execution not so much. There was a learning process.
If you recall, Xantrex, being big into inverters, introduced a 12-Volt system for RV manufacturers similar to the Volta. I think it was shortsighted to use 12-Volts. Obviously it’s easier to integrate today, but I haven’t heard much about it. I’d bet the future will be 48-Volts; or higher if supplied by chassis OEMs. I think that’s where Volta invested for the longer term, and it’s now paying off. Advances like these often develop over long periods of time in small steps. And I doubt the Volta system will be the last advance we will see in this area.
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03-12-2019, 10:31 PM
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#28
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Senior Member
Brand: Thor Motor Coach
Model: Chateau 31L
State: Florida
Posts: 2,063
THOR #12189
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Quote:
Originally Posted by Chance
Solar is included in new motorhome design from Thor, and was briefly mentioned above. More specs on total system is really needed. The issue I see is not so much solar being expensive, but rather that when these systems become very high in power flow, then the solar contribution becomes less important as a percentage of the total. We’ll just have to wait for all system specs.
Solar is always great to have to keep batteries charged and to power fridge during storage, etc.
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They're a little light on 'specs' I could only find this: https://voltapowersystems.com/wp-con...1.8.17_WEB.pdf
They only offer Class A & B systems, no Class C (figures...). I'm fairly confident a Class B system could be made to work in a Class C. A Class A system, maybe not so much.
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03-12-2019, 10:35 PM
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#29
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Senior Member
Brand: Thor Motor Coach
Model: Chateau 31L
State: Florida
Posts: 2,063
THOR #12189
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Quote:
Originally Posted by Chance
...I’d bet the future will be 48-Volts; or higher if supplied by chassis OEMs. I think that’s where Volta invested for the longer term, and it’s now paying off. Advances like these often develop over long periods of time in small steps. And I doubt the Volta system will be the last advance we will see in this area.
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Wouldn't that require all dependent systems to be 48V or do you see a converter in there? I need to do more reading but it would seem inefficient to step it down to 12v?
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03-12-2019, 11:31 PM
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#30
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Senior Member
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
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Quote:
Originally Posted by TheBreeze
Wouldn't that require all dependent systems to be 48V or do you see a converter in there? I need to do more reading but it would seem inefficient to step it down to 12v?
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48V auto electrical systems for mild hybrid is already a reality. We don’t need to speculate.
Yes, they use a DC-DC converter to step down a small amount of power from 48V to 12V (nominal) for items in vehicle which are already there, like lights, radio, power windows, windshield washer, etc.
It is expected that as new vehicles are designed with 48V electrical from the onset, many or all of these items will run on 48 Volts, so there should be no need for DC to DC converter.
The RV industry will likely follow a similar transformation in my opinion. Initially the use of 48V will be extremely limited, but it should become a new standard in time. Just my guess though.
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03-13-2019, 12:08 AM
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#31
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Senior Member
Brand: Thor Motor Coach
Model: Chateau 31L
State: Florida
Posts: 2,063
THOR #12189
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Quote:
Originally Posted by Chance
48V auto electrical systems for mild hybrid is already a reality. We don’t need to speculate.
Yes, they use a DC-DC converter to step down a small amount of power from 48V to 12V (nominal) for items in vehicle which are already there, like lights, radio, power windows, windshield washer, etc.
It is expected that as new vehicles are designed with 48V electrical from the onset, many or all of these items will run on 48 Volts, so there should be no need for DC to DC converter.
The RV industry will likely follow a similar transformation in my opinion. Initially the use of 48V will be extremely limited, but it should become a new standard in time. Just my guess though.
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I was watching a solar video (9 parts). The guy wants to eventually go to 24v. I see why things are headed higher (efficiency) but if he has to step everything down (today), I struggle to understand. All he seems to be doing is to introduce another point of failure (re: )
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03-13-2019, 12:58 PM
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#32
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Senior Member
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
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Quote:
Originally Posted by TheBreeze
I was watching a solar video (9 parts). The guy wants to eventually go to 24v. I see why things are headed higher (efficiency) but if he has to step everything down (today), I struggle to understand. All he seems to be doing is to introduce another point of failure .......cut......
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I would not personally consider 24V electrical system unless the vehicle and RV “house” was already set up for 24V. I’d keep it at 12V, or if making a change go up to 48V nominal (about 56V charging).
Regarding efficiency, keep in mind that in these new electrical systems the vast majority of stored energy is used at the higher 48 Volts to power inverter. Only a small amount of energy will have to be stepped down to 12V at present to power existing 12V items that are not yet available in 48V.
The DC-DC converter to step voltage down to 12V is mainly to keep a small battery charged. That small 12V battery will power lights, water pump, etc. The much larger 48V battery bank simply keeps the 12V battery topped off, for now. In time 12V water pumps, lights, and the like should be available in 48V models so they can run directly from high-capacity battery bank. The auto industry is going through similar issue with 48V electrical.
I’m not sure the benefits of any “Volta-like” system are worth the cost as a retrofit. It is really expensive to have it installed by others after the motorhome is built. Even from RV manufacturers, it adds a lot of cost. In the Winnebago Travato B, it’s about $20,000 more.
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03-13-2019, 01:11 PM
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#33
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Axis/Vegas Enthusiast
Brand: Thor Motor Coach
Model: Axis 24.4
State: Michigan
Posts: 9,837
THOR #1150
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A dual voltage system is quite common these days and, in fact, is in just about every EV produced today.
They have a high voltage system (typically 300+ volts DC for the traction motor) and a 12V system (which includes a 12V battery) for all of the conventional systems (especially cars from existing manufacturers, but even a Tesla has a 12V battery).
Typically included is a DC-DC converter to keep the 12V battery charged (and run the 12V systems when the car is "on") and a very high powered inverter/controller as none of the cars use a DC motor--usually synchronous or permanent magnet motors requiring A/C to operate.
Thus the more EVs are produced the more these kind of components (including the batteries) will come down in price due to scale.
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03-13-2019, 09:14 PM
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#34
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Senior Member
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
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Thanks to posted video, we now know Thor went all out with Level 4 system for luxury motorhomes.
3 inverters at 3600 watts each
Approximately 40,000 Watt-hours (36,000 usable) battery bank
Only difference is Volta rep said there is one 11,000 Watt generator.
Give me 1/3 of this system and I’d be a happy camper.
https://voltapowersystems.com/wp-con...evel-4_WEB.pdf
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03-13-2019, 10:13 PM
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#35
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Senior Member
Brand: Thor Motor Coach
Model: Chateau 31L
State: Florida
Posts: 2,063
THOR #12189
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Quote:
Originally Posted by Chance
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Give me 2/3 and I'd be doing the snoopy dance - coast to coast
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03-14-2019, 11:37 AM
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#36
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Senior Member
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
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The one important data point that’s missing is the cost of the system; but being a prototype they are not likely to disclose it.
Regardless, it’s difficult to fully appreciate the capabilities without a rough comparison. A 225 Amp-hour X 6-Volt golf cart battery stores about 1,350 Watt-hours, so at 50% useable, it works out to about 675 Watt-hours per traditional battery. It would therefore take about 53 golf cart batteries to equal the 36,000 useable Watt-hours this Thor prototype has available . For what it’s worth, that would be over 3,000 pounds of AGM batteries.
P.S. — The Volta standard system is approximately 1/3 the size since it only has one inverter sized to power a 30-Amp coach (30A X 120V = 3.6 kW). If the retail cost for the Travato Lithium package is in order of $20,000, this Thor with 3 inverter’s and almost 5 times the battery capacity must be in range of $50,000 or more. The one larger alternator is likely the only item that doesn’t cost proportionally more.
That’s a lot of cost, but maybe buyers paying $500,000 wouldn’t mind and extra 10% or so. Thoughts on costs?
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