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KYOON GRIFFEY JR posted:Out of curiosity, is there a premium that people would be willing to pay for a commuter-range EV over a gasoline equivalent? I don't feel that this was adequately answered, because 99% of the time that this comes up people want to boil it down to a simple question of saving gas money. I have several reasons to pay a premium that have nothing to do with saving gas. In fact I would pay this premium just to have the electric drive I want, even if it gets it's power from a small generator motor. Which I'm convinced would net amazing economy but for sake of argument let's say it's even worse than 30mpg. Just listen to this: -Low end torque. The obvious number one. From 0 rpm you have full wheelspinability. -INSTANT throttle response. If you could twitch the throttle fast enough it'll chirp the tires 10 times a second like it's the drat ABS going off. No amount of lightened flywheels and other engine parts will ever come close to what an electric does naturally. (not to mention the control this provides to replace TCS and ABS systems) -smooth power delivery. Silky smooth, and 100% from 0 right on up to peak. No warming up, no hesistation or power peaks/valeys from worn out plugs or bad gas, no excuses. Always consistent power that lays on, a torque curve so flat you couldn't touch it with a modern V12. -Silent. Yeah I know all the noise and vibration is fun in a race car. Not for my daily driver. -reduced parts. This is an area where I am displeased with current electrics. Why? Because they still entertain the idea of having a transmission. Not needed. Single speed reduction, done. Virtually no driveline slop to reduce that instant throttle and smooth power experience. When it comes to moving parts there's just no comparison, the suspension will have more parts than the entire driveline. Sure there will still be a cooling system and related support parts, but from a moving part standpoint we are much better off. -Easier to fix. All of the electronics could be made like modern network equipment. Self-diagnosing, practically hot swappable. Unplug some wires, swap a module, done. Redundant drive systems would be too easy not to add as an option. -Driveline layout options. 2 small motors up front? Awesome that takes care of power steering too. And road crown compensation. One motor per wheel? even better, that's the perfect AWD. It would steer like magic. One big fattie motor to the rear wheels? Cool drifter, bro. Our options just got a lot easier. -Off grid. Having that battery pack would be so loving awesome for a camper. Or a work truck. Particularly with that generator option. To make average driving power you only need 25HP or so. Throttle response, torque range, max RPM, all irrelevant. This drat generator can be an aircooled 1L 3 cylinder 6 valve pushrod lump that just gets milled out of a solid block of metal without so much as a headgasket. The only rotating part to seal is the crank to the electric head. No accessories, belts, hoses. But a turbo miller cycle would be cool. OK I'm starting to drift off here. Hermsgervørden posted:The unsprung mass would be a problem on in-wheel-motor cars with traditional suspensions, but the active wheel seems like it has the potential to nullify unsprung mass or even reduce it. Are there limitations of an active suspension that I'm not thinking of? Off the top of my head the only thing I can think of is a limited amount of travel, but then you just need to make the wheel bigger. Maybe the future of EV's is in 22" Rimzz. I'm not with you on this one. For as much as I love deleting parts, I feel that we have to keep the halfshafts and put the motors inboard. This is both because motors contain a lot of weight in copper/magnets/etc, and because those materials would not handle the shock/vibration of being inside a wheel. Even just the electrical wire connection I would prefer to avoid all of that flexing movement. The number one cause of electric motor failure is bearings, easier to protect from dirt/crud if we put it inboard. The second cause, insulation failure from overheating or from physical stress (usually from distortion of the soft copper from the magnetic forces it creates). This could somewhat reduce the size of brakes needed as most would be done through the motors, but for low speed and safety redundancy they can't be deleted. I say low speed because below a certain speed there's no energy recovery, we'd have to actually power the motor to continue using it as a brake. This would not be the most energy efficient but could pretty much eliminate brake wear, and (assuming multiple motor) control braking forces on a per-wheel basis to influence steering/control in the same way as putting down power. Because of substantially reduced brake heat+use I would entertain the idea of inboard brakes or drums. Or at least review the pros and cons. A big rotor on the front wheel to lock it up is hard to give up though no matter how burly the electric is, but if it doesn't get used will rust and cause trouble. So yeah, sorry I started to drift into rant mode but there are clearly some advantages here that even $800k cars can't touch. The only disadvantage in my opinion is upfront cost and weight. So perhaps the track racer will have to go without, but for a commuter/work car that should last a minimum of 30 years with the priority on being reliable, obvious choice.
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Feb 2, 2012 01:58
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| # ¿ May 2, 2024 08:11 |
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My first thought was also not good. Seems perfect for that little drone wing and perhaps some other things but without good density it might not be worth it for vehicles. I'm also quite skeptical of the charge/discharge rates, it might not be good for hybrid use either. Everything has it's use though. Aircraft are typically expensive, lightweight, full of exotic materials, and expected to fireball when crashed.
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Feb 14, 2012 02:58
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it sounds to me like this is a problem with the battery control. Especially in the case where someone had usd a 100ft cord and the voltage drop was too big for a charge, I know for a fact that you could at least pull a low power trickle charge that might take forever but at least not kill the battery. Instead it just kept trying to boot it into sucking down 20A and giving up. Typical of a lot of chargers, but they should have spent a little more on charger features considering this scenario. Same with the monitor circuits that are a bit of a drain. Some type of storage mode would have been a good idea. We all know this happens with lead acids too, those cheapass solar panels you can stick in the window are enough to keep them from totally discharging and sulfating. Lithium doesn't discharge itself nearly as fast.. I'd think a little solar panel would be a good idea. Of course, then you'll have to hear people complain that it takes that solar panel a full month to charge the battery but hey at least it's not bricked.
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Feb 23, 2012 15:52
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Naffer posted:Using the 11 weeks from full charge mentioned on the blog and the 53kWh capacity of the battery gives roughly 28 watts as a continuous load (which would require a big solar panel), not counting the self discharge of the battery pack. That seems somewhat high, and makes me think that it really is a software problem if it's a real problem at all. 28W seems awfully high, those battery monitor circuits really don't pull that much. And the self discharge effect really shouldn't bee that high. Amazing. something is really wrong here.
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Feb 24, 2012 23:11
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BonzoESC posted:Is the undisclosed surveillance hardware going to draw more than an iPad that can idle on 3G for weeks on the built-in 8mm thick 25 watt hour battery? I'm guessing the majority of it must be self discharge, or another way to look at it is not that 28W is getting used but just evaporating. It sounds like a lot because that sort of drain would kill a typical car battery in a few hours, but it's very small % of a 53kw battery. If we had more detail we might find that it's not linear.. http://en.wikipedia.org/wiki/Lithium-ion_battery Self-discharge rate 8% at 21 °C 15% at 40 °C 31% at 60 °C (per month)[4] parked temperature would be 21C on a nice day.. so if it was full when parked.. 53,000wh. 8% of that is 4240W. if we subtract 8% of the full capacity each month instead of 8% of what's left (not sure which one but lets go worst case) month 2: 48,760wh month 3: 44,520wh.. obviously not half drained yet. this is averaging like 6w not 28w.
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Feb 25, 2012 18:04
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| # ¿ May 2, 2024 08:11 |
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nice link.. i didn't know that thing was RWD!
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Jul 1, 2012 18:42
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