The “range–extended” EV (BEVx) considered

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edatoakrun said:
GRA said:
It will never be a scandal, because having the REx means that people are driving more EV miles, not less...
LeftieBiker said:
Given how unpleasant the i3 Rex seems to be to drive in Rex mode, I doubt that many people will drive around on the ICE.
I think both of your assumptions are incorrect.

The comment below was posted yesterday:
<snip description of uncoded i3>

That statement particularly applies to California.

BMW has claimed to have developed the DC infrastructure on California freeways, but in fact only promoted the installation of single-unit, CCS-only DC chargers, that often supply far lower than the (slow) 24 kW claimed (when they function at all) and at far higher cost-per-mile than by just filling up with gasoline and driving on the REx.

BMW has not only tolerated, but for all practical purposes actually encouraged California i-3 REx buyers to code to enable long gas-fueled trips by evading the BEVx regulations.
Which does nothing to invalidate my assumption, as the car is undoubtedly being driven far more often in total, including fully using the battery on trips where the car simply wouldn't be used otherwise. You are correct that the situation in most of California's major metro areas is ill-suited for the REx when crippled, IF people want to take inter-regional road trips. Most of our metro areas have common road trips that involve longish flat approaches which deplete the battery, followed by long climbs afterwards which the Rex is incapable of managing safely on its own. For people who use the REx as intended by CARB, as a way to relieve range anxiety and boost PEV sales for local use rather than a means to enable a road trip, there's no issue. That the REx has boosted total PEV sales is pretty clear, as both my personal counts as well as sales figures indicate that the REx outsells the BEV i3 by 2.5 or 3 to 1. Given that the base car goes for $42k, it's pretty much a no-brainer to spend another $3k (1/14th more) and more than double the car's utility, while ensuring that its full battery capacity is regularly used.

It's the % of the population who are unwilling to spend $45K for a car and be unable to use it for common road trips that will code. I personally think the BEVx reg is stupid and would undoubtedly code if I were willing to spend that much on a car instead of say a Volt, which is a better road trip car in any case. IMO they should just have been classified as PHEVs, but that's on BMW for wanting to get as many credits as they could by selling as many cars that would qualify for unlimited white HOV stickers, given the limited number of green HOV stickers that were originally available. As it was, CARB said uh-uh, you get green stickers, but did give them the full credits. And then the Legislature kept increasing and finally eliminated the cap on green stickers, by which point BMW was perfectly happy to sell quite conventional PHEVs (with far too limited AERs in my opinion; I believe CARB should impose a minimum AER of say 20 miles) across their line, instead of the highly specialized REx. Hopefully they'll just eliminate the BEVx category now.
 
This reply is to a post originally made in the "Leaf 2 : What we know so far (2018 and later)" topic, where the OP asked that OT posts on this subject be moved here. I've quoted the entirety of that post so that people don't have to go back and forth between threads.

Interleaf said:
GRA said:
As stated, that's exactly what they did, to allow them to get full credits for a BEV instead of partial credits for a PHEV, in a category they themselves had asked be established, ...
I think you have missed the point. The point is that it was CARB who dictated that a SEV or MSEV (minimal Rex Serial EV) is a bad idea and must not receive full credit. BMW was just reacting to the brainless rules of CARB, pushed by its incompetent and ideological sociology graduates, and was just optimizing given the constraint imposed by CARB. It is NOT BMW at fault. It is CARB at fault. If a city (like my city) converts every other road lane to bicycle-only, and then traffic jams become 5 times worse, can you blame the drivers for not driving on the bike lanes and causing traffic jams? In justice, you go to the source of the injustice and apportion blame. You do not blame the victim. BMW is just dancing to the rules of CARB.
No, CARB was acting to prevent BMW or anyone else from gaming the rules to maximize emission credits while building PHEVs. That the reg doesn't meet your or my priorities is correct, but unlike CARB our priorities aren't dictated by law. From their mission statement:

The California Air Resources Board is a part of the California Environmental Protection Agency, an organization which reports directly to the Governor's Office in the Executive Branch of California State Government.

The Mission of the California Air Resources Board:

To promote and protect public health, welfare and ecological resources through the effective and efficient reduction of air pollutants while recognizing and considering the effects on the economy of the state.

The Major Goals of the Board are to:

  • Provide Safe, Clean Air to All Californians
    Protect the Public from Exposure to Toxic Air Contaminants
    Reduce California's Emission of Greenhouse Gases
    Provide Leadership in Implementing and Enforcing Air Pollution Control Rules and Regulations
    Provide Innovative Approaches for Complying with Air Pollution Rules and Regulations
    Base Decisions on Best Possible Scientific and Economic Information
    Provide Quality Customer Service to All ARB Clients

Note that reducing air pollution is CARB's major priority, and the worst air pollution is generated and found in the major metro areas (and the southern San Joaquin Valley, but much of that pollution is generated in the Sacramento and San Francisco Bay Metropolitan areas and blown there by prevailing winds). Ensuring the maximum reduction in emissions in those areas is their top priority, and the regs they write are designed accordingly.

Interleaf said:
GRA said:
CARB's opinion was that it might make BEVs more acceptable to some people who would otherwise be turned off by their short range and consequent range anxiety, so more would be sold and more miles would be driven electrically. It had just that effect, which as I mentioned is shown by the relative sales proportions of the i3 BEV vs.the REx.
It was just an opinion by CARB and a wrong opinion. It held back the adoption of BEVs because the i3 Rex has little functionality and prevents people from driving intelligently. The huge engine also made the thing unnecessarily expensive and difficult to maintain. So many times I had to suffer due to almost running out of charge with my Leaf, and having to cancel my plans. A minimalist genset, as little as 5 kW or even less that could be turned on at anytime and could charge the EV back to 100% if necessary (i.e. not this bizarre 'hold mode') would have ameliorated range anxiety. Are you not aware that the adoption of BEVs has been extremely anemic? Why do you think it is so anemic? (Range Anxiety)
The adoption of BEVs wasn't held back because overpriced BMW i3 RExs didn't have a hold mode, it was because batteries were and remain the single most expensive component, and for most people the value for the money proposition of a short-range BEV or BEVx simply made no sense; for most people it still doesn't. Even the better value of a PHEV is a tough sell for many, absent the HOV stickers. While battery prices have dropped considerably since the i3 was introduced, allowing people to afford longer range BEVs, without subsidies and perks the adoption rate would change from anemic to almost non-existent. As to why BMW chose to use a REx which you believe to be too large, they pulled an existing motorcycle engine out of the bin and made the minimum modifications they had to for a car which they knew would be a very low production item, to keep costs down.

As it is, the i3 REx's engine is just about able to maintain 70 mph on flat ground with no wind, which is okay for flat California urban areas to get you home, but inadequate if you have to do any climbing at freeway speeds. If you want a more versatile car, you really need more power (and more range), and BMW seems to have provided some more with the i3 REx's mid-life update. That you may find a design with an even smaller engine acceptable is all well and good, but I believe (and I imagine CARB and the car manufacturers do too, probably based on much more solid data than I have) that the total market for such a car is some miniscule % of an already tiny market for PEVs. Here's what BMW has to say about how much the REx gets used:

According to BMW, at the beginning of the i3 release, the use of range-extender was much more than the carmaker expected, more than 60%. Over time it has decreased significantly, with some people almost never using it, and by 2016 it is being regularly used in fewer than 5% of i3s.
https://en.wikipedia.org/wiki/Range_extender_(vehicle)

We've had at least one member here who's made a homebrew trailer-mounted range extender - Ingineer (the EE behind EVSEupgrade.com) built one using a microturbine and showed it around. Use the search function for" range extender" and author "Ingineer" and you should find relevant posts, at least some of which are in this thread.

There's also the issue of noise and vibration of small piston engines and consequently their acceptability to customers, not to mention the low reliability of such an engine forced to run at near max. power most of the time. BMW seems to have made improvements at least in the NVH area with the MLU, and we'll see how the reliability goes.

Interleaf said:
GRA said:
]Now that BEVs with equal or greater range than the REx are available for under $40k, the justification for such a design has faded away to nothing.
Certainly disagree with this. The Leaf2 is only 150 miles of range and that is insufficient. Even the T3.220 does not offer the confidence that on a freezing dark rainy day you will get to your destination that is only an hour and half away. A "backup power" (and not a range extender) will even be needed in a 310 mile range EV.
Not for local/commute use, it isn't, for most people. 150 miles EPA is a no-worries range of 100 miles, or if you want to be really conservative (given urban CA's mild winters) 90 miles, both with a reserve. When the battery has degraded to EoL at 70% of original capacity, that still provides at least 70 miles (or 60 if really conservative) of no-worries range, which is still more than enough for everyone other than super- and mega-commuters (super-commuter def.: 1-way commute of at least 50 miles or 90 minutes. Mega replaces "or" with "and"). It also allows use as a regional car (day trips, short overnights), possibly including a single en-route or destination charge, for several years.

200+ miles allows regional plus (weekend) road trips when new, plus buys greater longevity for commute/local use, and covers many of the super-/mega-commuters as well. If you want a do-everything car including road warrior trips, then it's still ICE/HEV/PHEV.
Interleaf said:
GRA said:
That some owners would want/need to use their cars in ways that limiting the REx to only come on when the SoC had fallen to 6.5% wouldn't allow was foreseeable, but was considered acceptable by CARB. I thought then and now that anyone willing to spend that kind of money for a PEV would be likely to drive the car to maximize the amount of electric driving they did, so the limitation wasn't needed, but given the amount of PHEV drivers who never use (if they even know) of 'hold' modes, that's not necessarily the case.
You would need to reprogram the Rex to arrive at the silly 'hold mode' which is only at 50% in N.A. and is not variable and does not allow re-charging. This hack is not sanctioned by BMW and may void the warranty. In today's nanny culture, no one will take this risk. Besides a 'hold mode' is the wrong idea to begin with. If you go in hold mode at 30%, you are stuck at 30%.
No, you just need to allow the 'hold' mode to be selected at up to 75%, as is allowed elsewhere; up to 100% (as most PHEVs allow) would be the ideal. As to who's willing to take the risk, plenty of i3 owners who'd benefit by it have, but there's simply no need to do so given the many other less expensive PEV options people have now.

Interleaf said:
GRA said:
No, it can be driven for about an hour (maybe 1.5 hours in the current model), and then you have to stop and fill up.
Nope, a Rex driver will stop at the next gas station and fill up, rather than look for a charger, drive out of way, and wait for 1 to 4 hours for the i3 to charge up, everytime they drive 100 miles.
After first driving 72 (now 97) miles on the battery. Anyone who'd regularly drive beyond the range where they have to stop more than say twice to fill the tank of an i3 REx is in the wrong car - there are plenty of PHEVs available that make far more sense than that, at a much lower price.

Interleaf said:
GRA said:
If BMW's intent was to discourage BEV adoption, I'd say they've failed. As to a REx, I personally have always thought that a straight PHEV was more generally salable and so it's proved, but the REx probably drives more miles (and a higher %) electrically, which was CARB's intent. That you attribute this to politics/ideology of someone at CARB is your opinion - the record of who did what and why is pretty clear, and available to the public.
Sorry, this makes no sense. First off, it is well known that BMW (and others) wishes not to cannibalize its existing line of luxury ICE, so they have little incentive to push EVs. A straight PHEV will cost 50% more than a MSEV (minimal genset serial EV) and offer nothing more, and be a lot more costly to maintain and fuel, and produce a lot more pollution. The MSEV concept has not even been tested yet, but you claim that a PHEV is superior to an MSEV? The i3 Rex is not an MSEV.
Sure, the i3 was a compliance play, I've said as much. But why would BMW or any other car manufacturer spend a ton of money developing a car which they think will only sell in numbers that they can count on their fingers and toes? A PHEV doesn't cost 50% more than the car you describe, it's cheaper and will remain so as long as the battery pack is the single most expensive component. An ICE costs a few hundred dollars and once you've got it, unlike a BEV/BEVx or what you're describing, doubling the car's range when running on fossil fuels takes little extra weight or space, and costs next to nothing. Battery packs still cost several thousand dollars, and doubling their range doubles the cost and also reduces the car's efficiency in both CD and CS modes. Which is why PHEVs are cheaper than BEVs and also more salable, at least up til now; longer range, less expensive packs are bringing prices and capabilities closer together, but the PHEV still benefits from faster refueling everywhere, plus free heat in winter that has no effect on range.
 
GRA said:
No, CARB was acting to prevent BMW or anyone else from gaming the rules to maximize emission credits while building PHEVs. That the reg doesn't meet your or my priorities is correct, but unlike CARB our priorities aren't dictated by law.
Are we not saying the same thing? That the law was wrong, and the regulators were even more wrong? That perfection is the enemy of the good?

Besides, CARB's mandate is to "reduce" pollution and not to "eliminate" pollution. They never understood the concept of a Rex and confused that with a PHEV. And then they required that the Rex be able to power the EV without the help of the batteries - which is as idiotic as it can get.

On the other hand, a small 5 kW generator, which cannot propel the EV without the batteries, can take the EV to the next charge station. The point is a matter of pragmatism. Few EV drivers run out of range. But they do suffer from range anxiety a lot of time, and they have to modify their behaviour (i.e. not heat the cabin, reduce the number of destinations in a day), and they end up not achieving certain unplanned destinations because the penalty of running out of charge is astronomic.

That is why a minimalist SEV makes a lot of sense. It is the safety net for the trapeze. If the driver has made a mistake in electric consumption (i.e. heated the cabin too much), they can still survive. It can be as small as 5 kW, which means it will fit almost anywhere in the vehicle, and the tank can be small. It can also be used to heat the cabin at almost 100% efficiency. But the driver must be able to turn it on at will to charge the batteries in advance. However, being a minimalist engine, there is no way to travel long distances, and hence it does not incentivize the user to drive on fuel.

Problem is that even with 300 mi range EVs, this issue will not go away, no matter how many more QC stations are added to the network. There will always be pockets without QCs, or broken QCs, or lineups at QCs.
 
Interleaf said:
GRA said:
No, CARB was acting to prevent BMW or anyone else from gaming the rules to maximize emission credits while building PHEVs. That the reg doesn't meet your or my priorities is correct, but unlike CARB our priorities aren't dictated by law.
Are we not saying the same thing? That the law was wrong, and the regulators were even more wrong? That perfection is the enemy of the

On the other hand, a small 5 kW generator, which cannot propel the EV without the batteries, can take the EV to the next charge station.

That is why a minimalist SEV makes a lot of sense. It is the safety net for the trapeze. If the driver has made a mistake in electric consumption (i.e. heated the cabin too much), they can still survive. It can be as small as 5 kW, which means it will fit almost anywhere in the vehicle, and the tank can be small.

My father added a small efficient 4.5kw slow turning genset to his Miles Zx40 EV.

With a flat battery we could slowly propel ourselves directly off the generator to 28-33mph we ran some tests running strictly off the genset and were in the 90mpg area +\- 5% without any charging and dead batteries.

I have a feeling an OEM could do better than our rather antique inefficient system and likely meet the emissions requirements as well.

Downsizing and Improving fuel economy of the Rex would reduce the up to 100 grams of NOx per gallon produced by the refinery, drilling and transport of each
Gallon of gas and reduce CO2 emissions saving resources.

Just because your tailpipe makes less pollution doesn't mean the supply side does, but reducing resource use can actually affect the massive supply side pollution contaminating your neighbors air and water.
 
Interleaf said:
GRA said:
No, CARB was acting to prevent BMW or anyone else from gaming the rules to maximize emission credits while building PHEVs. That the reg doesn't meet your or my priorities is correct, but unlike CARB our priorities aren't dictated by law.
Are we not saying the same thing? That the law was wrong, and the regulators were even more wrong? That perfection is the enemy of the good?
No, we're not saying the same thing. I'm saying that given MY (and presumably your) priorities, CARB was wrong, but given theirs they were right.

Interleaf said:
Besides, CARB's mandate is to "reduce" pollution and not to "eliminate" pollution. They never understood the concept of a Rex and confused that with a PHEV. And then they required that the Rex be able to power the EV without the help of the batteries - which is as idiotic as it can get.
They confused nothing, they wanted to prevent companies from gaming the PHEV rules to get full emission credits and they succeeded, as shown by the fact that the i3 REx is the sole BEVx that has ever been offered to the public. There are commercial vehicles that are similar, but they tend to be delivery vans, and even they usually have more powerful ICEs (or in some cases fuel cells) than you are talking about, due to operational requirements. But nothing in the BEVx reg dictates the power output of the ICE - that was BMW's decision to use an available low-cost option. Considering the safety complaints that have been raised by i3 REx owners about that engine's lack of power, my opinion is that the i3 REx needs more power, not less, and BMW apparently agrees, as they seem to have increased the output with the MLU.

Interleaf said:
On the other hand, a small 5 kW generator, which cannot propel the EV without the batteries, can take the EV to the next charge station. The point is a matter of pragmatism. Few EV drivers run out of range. But they do suffer from range anxiety a lot of time, and they have to modify their behaviour (i.e. not heat the cabin, reduce the number of destinations in a day), and they end up not achieving certain unplanned destinations because the penalty of running out of charge is astronomic.

That is why a minimalist SEV makes a lot of sense. It is the safety net for the trapeze. If the driver has made a mistake in electric consumption (i.e. heated the cabin too much), they can still survive. It can be as small as 5 kW, which means it will fit almost anywhere in the vehicle, and the tank can be small. It can also be used to heat the cabin at almost 100% efficiency. But the driver must be able to turn it on at will to charge the batteries in advance. However, being a minimalist engine, there is no way to travel long distances, and hence it does not incentivize the user to drive on fuel.
What you mean is that a minimalist SEV (your coinage, AFAIA) makes sense to YOU. The question is whether it made sense to the public in reasonable numbers, and based on everything I've seen the answer is no. It makes even less sense now, when cheaper BEVs can provide the extra range/HVAC use that the REx would otherwise provide.

Interleaf said:
Problem is that even with 300 mi range EVs, this issue will not go away, no matter how many more QC stations are added to the network. There will always be pockets without QCs, or broken QCs, or lineups at QCs.
Sure, but for such trips you want a PHEV, not a BEVx, as it needs to be capable of freeway speeds and long range. A Prime, Clarity PHEV, or Volt works just fine for those. Eventually, either batteries will improve enough and charging infrastructure get dense enough that the occasional QC that's out of service will be a minor irritation (as an out of service gas station is now) rather than a crisis, or else bio-fueled PHEVs or H2 PHFCEVs will cover the longer trips. It makes no sense to haul around several hundred pounds of expensive, excess battery pack just to cover the rare long-distance trip, when lighter, smaller, cheaper and more practical options with similar emissions are available.
 
GRA said:
Interleaf said:
Problem is that even with 300 mi range EVs, this issue will not go away, no matter how many more QC stations are added to the network. There will always be pockets without QCs, or broken QCs, or lineups at QCs.
Sure, but for such trips you want a PHEV, not a BEVx, as it needs to be capable of freeway speeds and long range. A Prime, Clarity PHEV, or Volt works just fine for those. Eventually, either batteries will improve enough and charging infrastructure get dense enough that the occasional QC that's out of service will be a minor irritation (as an out of service gas station is now) rather than a crisis, or else bio-fueled PHEVs or H2 PHFCEVs will cover the longer trips. It makes no sense to haul around several hundred pounds of expensive, excess battery pack just to cover the rare long-distance trip, when lighter, smaller, cheaper and more practical options with similar emissions are available.

Arguing that we should burn fossil fuels because a charger might be broken somewhere is a bizarre concept... why not just put MORE fast chargers in the ground? Backup power sources for the chargers?

That's a REQUIREMENT for gasoline stations in Florida. They have to have a generator to power the gasoline pumps. Anyhoo, it's always great to listen to folks rationalize what will work who have never owned an EV.

If the batteries are too expensive (by your statement), then what would batteries and ridiculously expsenvie fuel cells and mega expensive H2 do to fix that? Nothing, of course.

I hate to be the bearer of bad news, but the light duty vehicle fleet is firmly on course to be battery powered in my lifetime. Hydrogen will be the tax payer funded experiment thatnits always been. Physics wont change.
 
TonyWilliams said:
GRA said:
Interleaf said:
Problem is that even with 300 mi range EVs, this issue will not go away, no matter how many more QC stations are added to the network. There will always be pockets without QCs, or broken QCs, or lineups at QCs.
Sure, but for such trips you want a PHEV, not a BEVx, as it needs to be capable of freeway speeds and long range. A Prime, Clarity PHEV, or Volt works just fine for those. Eventually, either batteries will improve enough and charging infrastructure get dense enough that the occasional QC that's out of service will be a minor irritation (as an out of service gas station is now) rather than a crisis, or else bio-fueled PHEVs or H2 PHFCEVs will cover the longer trips. It makes no sense to haul around several hundred pounds of expensive, excess battery pack just to cover the rare long-distance trip, when lighter, smaller, cheaper and more practical options with similar emissions are available.

Arguing that we should burn fossil fuels because a charger might be broken somewhere is a bizarre concept... why not just put MORE fast chargers in the ground? Backup power sources for the chargers?
Tony, where have I said otherwise? I'm talking about the interim period, when people are transitioning to PEVs. At such times, PHEVs make the most sense to the general public, because of current BEVs' limited range, long charging time, limited charging infrastructure and higher price. As those issues improve the need for fossil fuels disappears, but until then fossil-fueled PHEVs remain the most practical PEV road trip option for most people.

TonyWilliams said:
That's a REQUIREMENT for gasoline stations in Florida. They have to have a generator to power the gasoline pumps. Anyhoo, it's always great to listen to folks rationalize what will work who have never owned an EV.

If the batteries are too expensive (by your statement), then what would batteries and ridiculously expsenvie fuel cells and mega expensive H2 do to fix that? Nothing, of course.
When have I ever not had a caveat that the prices of H2 and fuel cells (as well as batteries or biofuels) must decrease to the point where they are competitive with fossil-fueled options? Never - replacement of fossil-fuels by whatever tech is dependent on the relative cost. I've said so repeatedly, and you know that I've said so repeatedly. The post you quote also alluded to cost issues:

Eventually, either batteries will improve enough and charging infrastructure get dense enough that the occasional QC that's out of service will be a minor irritation (as an out of service gas station is now) rather than a crisis, or else bio-fueled PHEVs or H2 PHFCEVs will cover the longer trips. It makes no sense to haul around several hundred pounds of expensive, excess battery pack just to cover the rare long-distance trip, when lighter, smaller, cheaper and more practical options with similar emissions are available.
Which of these options will happen first, or indeed whether any of them will, isn't predetermined.

TonyWilliams said:
I hate to be the bearer of bad news, but the light duty vehicle fleet is firmly on course to be battery powered in my lifetime. Hydrogen will be the tax payer funded experiment thatnits always been. Physics wont change.
You've often expressed your opinion that it's a done deal, while I believe that it isn't settled yet, and whether we see a single tech completely take over or (IMO the more likely option) different techs or combinations of techs are used for specific niches, remains to be seen. We'll have to wait a decade or two to find out. As to you being a bearer of bad news, that would only be the case if someone were a partisan of a particular tech, and since I've pointed out repeatedly that I simply don't care which non-fossil-fueled net-zero and preferably ZEV tech succeeds, only that at least one of them does, it will be great news for me whichever one(s) get there.

In any case, we've had the whole H2/FCEV vs. BEV debate ad nauseum, so do we really need to repeat it in this thread as well? Anyone who wishes to see that may look in the H2 and FCEV topic for one of the multiple repetitious rounds of argument.
 
edatoakrun said:
As in my OP If you want a BEVx to drive from the bay area to Tahoe during the Winter with one stop, you'd need ~ 20 kWh available from the pack, and ~8 kW, for a mid-size car like the LEAF, assuming you did not require kWh for heating the passenger cabin, but used your hydrocarbon fuel instead.
No need to burn fuel in a gas fired furnace for cabin heating. When the Rex is on, 75% of the energy is wasted as heat. Use the heat from the Rex to heat the cabin.
 
ydnas7 said:
the problem with a range-extended BEVx is that a series hybrid is not as efficient as a parallel hybrid.
http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=36030&id=35598
the BMW i3 is 3x more efficient in EV than ICE mode
vs
the Toyota Pip is 1.9x more efficient in EV than ICE mode
vs
the 2016 GM Volt is 2.5x more efficient in EV than ICE mode

the point is, gen to elec, elec to motor is less efficient than motor through gearbox to wheel
Not really when you consider that a serial EV does not need a transmission, as a PHEV would need. Also that the Rex in a SEV is fine-tuned to operate at its maximum point of efficiency, instead of having to change its RPM to match that of the wheels. Finally, a SEV Rex can be so small, as small as 5 kW, that no 100 kW engine can match its efficiency, especially if you consider that a smaller engine will burn so much less gas than a large engine, and hence produce a lot less waste than a large engine. If ICE are only 25% efficient, then the larger the engine, the more energy is being wasted.

If I get to my destination via a 5 kW Rex, I will create about 3.5 kWh of waste per hour. But with a PHEV and a 100 kW engine, I will produce 70 kWh of waste -- 20 times more waste, pollution, and emissions to get to the same destination. So there is no way that a PHEV can be more efficient than a SEV.
 
Interleaf said:
edatoakrun said:
As in my OP If you want a BEVx to drive from the bay area to Tahoe during the Winter with one stop, you'd need ~ 20 kWh available from the pack, and ~8 kW, for a mid-size car like the LEAF, assuming you did not require kWh for heating the passenger cabin, but used your hydrocarbon fuel instead.
No need to burn fuel in a gas fired furnace for cabin heating. When the Rex is on, 75% of the energy is wasted as heat. Use the heat from the Rex to heat the cabin.

Did you cut off his quote? I see nothing here about a furnace for heat, just burning fuel. You two seem to be saying the same thing.

Interleaf said:
ydnas7 said:
the problem with a range-extended BEVx is that a series hybrid is not as efficient as a parallel hybrid.
http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=36030&id=35598
<span>the <a href="http://www.mybmwi3.com/forum" class="interlinkr">BMW i3<span class="tip">Visit the BMW i3 Forum</span></a> is 3x more efficient in EV than ICE mode</span>
vs
the Toyota Pip is 1.9x more efficient in EV than ICE mode
vs
<span>the 2016 <a href="http://www.myelectriccarforums.com/forum/viewforum.php?f=29" class="interlinkr">GM Volt<span class="tip">Visit the GM Volt Forum</span></a> is 2.5x more efficient in EV than ICE mode</span>

the point is, gen to elec, elec to motor is less efficient than motor through gearbox to wheel
Not really when you consider that a serial EV does not need a transmission, as a PHEV would need. Also that the Rex in a SEV is fine-tuned to operate at its maximum point of efficiency, instead of having to change its RPM to match that of the wheels. Finally, a SEV Rex can be so small, as small as 5 kW, that no 100 kW engine can match its efficiency, especially if you consider that a smaller engine will burn so much less gas than a large engine, and hence produce a lot less waste than a large engine. If ICE are only 25% efficient, then the larger the engine, the more energy is being wasted.

If I get to my destination via a 5 kW Rex, I will create about 3.5 kWh of waste per hour. But with a PHEV and a 100 kW engine, I will produce 70 kWh of waste -- 20 times more waste, pollution, and emissions to get to the same destination. So there is no way that a PHEV can be more efficient than a SEV.

Your reasoning is off. Just because you have a 100kW engine doesn't mean you are running it at 100kW the whole time. If that engine is 25% efficient when run at 5% WOT (Wide Open Throttle) - 5kW - then it is exactly the same amount of energy wasted as a 5kW engine run at WOT. The benefit would be, as you point out, improving the small genset's efficiency by fine-tuning it for 5kW. So the question becomes - how much efficiency can be gained from that tuning? If the 100kW engine is 25% efficient at 5kW, can the 5kW engine get to 30%? 35%?
 
TonyWilliams said:
Arguing that we should burn fossil fuels because a charger might be broken somewhere is a bizarre concept... why not just put MORE fast chargers in the ground? Backup power sources for the chargers?

As a consumer, this is absurd. I am not so wealthy that I can simply go out and install chargers anywhere that I may need them. If I had that kind of money, I'd just buy a Tesla. No, if I want to dramatically decrease my footprint today, my best bet is a PHEV or BEVx. That's exactly why I have a PHEV to compliment my BEV.

In the long term, you are correct. This is the solution for an EV future. But I'm not going to sit idly by and wait for this to happen - I've already changed my "fleet" to work with what is available today.
 
GetOffYourGas said:
Did you cut off his quote? I see nothing here about a furnace for heat, just burning fuel. You two seem to be saying the same thing.
I am pretty sure that @edatoakrun implied in a couple of other posts that the fuel would be directly combusted for cabin heat. That is why he favors propane as the fuel, as it can be combusted in the cabin without elaborate exhaust consideration, and when the vehicle is stationary. But I am pretty sure that he is aware of engine heating. I brought that up because it was not obvious and his fine post may give the misimpression that furnace heating is required in a SEV. It is not.
 
Interleaf said:
I am pretty sure that @edatoakrun implied in a couple of other posts that the fuel would be directly combusted for cabin heat...
Yes, I stated that, in my first post.

="Interleaf"...That is why he favors propane as the fuel, as it can be combusted in the cabin without elaborate exhaust consideration, and when the vehicle is stationary...
Perhaps greater advantages are:

Propane infrastructure is already quite mature and ubiquitous in the USA, needing only to be slightly adapted (longer hours, self-service?) for even more convenient use by to BEVx drivers

Propane is not a GHG, is harmless to human (and other) life in low concentrations, and has relatively benign combustion emissions.

Propane is stable. A canister can last for decades without leaking, degrading, or gumming up your ICE (like gasoline does) when you finally decide use it.

="Interleaf" ....I am pretty sure that he is aware of engine heating...
I am, but consider the added complexity and limited benefits from using liquid coolant/heatent to capture the waste heat from a 5 to 10 kW ICE, heat which would only be available on extended trips, and then only useful during very cold weather.

IMO, an efficient heat pump (which could easily be set up accept waste heat from an air-cooled ICE, when occasionally available) with combustion-back-up for occasional long trips at very low ambient temperatures, would probably be more practical.
 
Direct Propane heating creates a lot of water vapor, a means of dehumidifying the air would be necessary
(Coming from a guy with an ev with a small propane heater)
 
Near-confirmation of the long- rumored Mazda "electric...equipped with a charge-supplementing generator" vehicle.

It remains to be seen whether Mazda will somehow manage to do what BMW failed to (IMO) accommodate CARB regulations and still produce a functional “range–extended” EV.

Though I don't see how that is possible, unless Mazda can change the current idiocy of CARBs BEVx requirements, battery depletion prior to generator operation and a tiny fuel tank, or it just classifies its BEVx as a PHEV in California for compliance purposes.

Mazda’s Rotary Engine Returns for 2019 — Just Not How You Had Hoped

...Mitsuo Hitomi, Mazda’s global powertrain head, gave us a timeline to sink our teeth into. The year of the Wankel will be 2019, but it’s not coming back how you imagined. Instead of dropping it into a high-revving performance vehicle, Mazda thinks a rotary would make the perfect gas-powered range extender for its upcoming electric vehicle.

“I think that’s probably what it will be,” Hitomi told Automotive News during a sneak preview at the Japanese carmaker’s Japanese proving grounds.

According to Hitomi, Mazda Motor Corp. feels that the rotary’s ability to make gobs of power in a small, low-vibration, package would make it an ideal range extender on its first battery-powered car. But it also serves as a nod to the company’s heritage and keeps rotary R&D alive.

Akira Kyomen, program manager for vehicle development said the new EV would come in two flavors — purely electric or equipped with a charge-supplementing generator. Mazda’s plan is to market the basic EV in Europe, Japan, and China but acknowledged that North Americans clock more daily miles on average and would appreciate something to alleviate range anxiety.

Mazda says its new EV architecture, set to arrive in 2019, will accommodate BEVs with or without range extenders — as well as hybridized powertrains...
http://www.thetruthaboutcars.com/2017/10/mazdas-rotary-engine-returns-2019-just-not-hoped/
 
Maybe this little rotary engine will work as a good range extender:
http://revolution-green.com/liquidpiston-enters-uav-arena-revolutionary-rotary-engine/

It looks to be much lighter weight and better fuel economy than most engines.
 
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