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  1. C

    Controllers - do they only manage duty cycle?

    As major said the back EMF of the motor has to be factored into the equation and this results in you needing more and more system voltage to get higher motor rpm. With regards to throttle response it depends entirely on how the system has been designed. Some will work in a way where the speed...
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    Thread for new battery breakthrough PR releases

    Storage for emergency backup possibly. Nevertheless batteries that don't self discharge is a step in the right direction towards eliminating/reducing their downsides.
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    Brushless dc motor with 5 power wires

    Hmm, that was just for a bldc. There a couple of different configurations that these can take. Most computer fans are 2 phase, or 4 pole bldcs. That's what your motor could possibly be. 10 degrees doesn't sound particularly high for a motor with a low pole count though. I'm wondering if the...
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    Brushless dc motor with 5 power wires

    My guess is it's wound like this with the white wire as the common that connects all coils to ground. Possibly at least. Try applying a small current down two of the wires and see how it cogs.
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    Thread for new battery breakthrough PR releases

    I was under the impression, from things I've read, that current lithium ion technology, as found in our 18650s, has reached a level of stagnation. That is we've kind of reached a theoretical maximum (energy density) for what the current chemistry can provide. This is why we haven't seen any...
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    Thread for new battery breakthrough PR releases

    EU countries can't see that.
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    Thread for new battery breakthrough PR releases

    I guess all the claims made by various companies are bunk then. I'm sure Toyota, for one, have said they'll be using solid state batteries by 2020.
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    Thread for new battery breakthrough PR releases

    Haha well I understand the problem with the mode of transportation, but the claims written by the super cap guys? Saying that batteries cannot accept the current levels required for efficient regen braking? That's obviously not true, unless we're talking emergency situations. I could see a...
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    Thread for new battery breakthrough PR releases

    Some of that doesn't make sense. Especially with regards to the regen braking. Rapid charging can provide in excess of 100kW straight into the battery so there's hardly a lack of charging capacity when needed. The only time this wouldn't be enough is if you needed to emergency brake... If...
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    Thread for new battery breakthrough PR releases

    That is interesting but would place a phenomenal amount of pressure on the charging system to keep your battery from exploding.
  11. C

    Thread for new battery breakthrough PR releases

    How is that a problem? A 1C discharge of a 10-12Ah cell is already as good as something like the NCR18650GA/PF at ~3C. If 2C of these new cells would be anything like 3C of the old ones (in the way then discharge curves compare) that'd make them ridiculously good. 20-25A discharge currents...
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    Thread for new battery breakthrough PR releases

    943 watt hours per kg...that's 4-5 times current 18650s... All these emerging battery techs, something needs to make it from the laboratory to everyday life.
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    Thread for new battery breakthrough PR releases

    That makes me wonder what the current hybrid busses I see around town have in them now. I always assumed that the onboard storage could soak everything that the regen could kick out but maybe not...if not then for sure that's a brilliant application for them. The same is true for an all...
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    Thread for new battery breakthrough PR releases

    With an energy density better than 115Wh/kg. The decent 18650s of today are at 200+ Wh/kg. 115 is certainly a very impressive figure for a completely chemical free solution. Not great for bikes or cars in a completely practical sense but it's a great step in the right direction. Of course...
  15. C

    13s 15p or 20s 10p all things being equal.

    You need voltage headroom over the motors back EMF to keep providing power at higher rpms. So if acceleration is really what you are after then voltage is what's required to get you there. That's the simple answer.
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    Thread for new battery breakthrough PR releases

    The thing is the standard li-ion tech of today will keep improving pretty much how it already has been doing. If one of the new emergent technologies should actually do what they've said they could, then we could be looking at 7000-10000mAh 18650s...once the tech is secured that could happen...
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    Thread for new battery breakthrough PR releases

    Well there are lots of people who sit below the curve and there are many that sit above it too. In all circumstances you're going to get extremes included. Some people will pedal to the metal the car regularly, some will use the air con all the time, others will only charge the car at super...
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    Thread for new battery breakthrough PR releases

    Interesting but no mention of energy density or charge/discharge characteristics. I'm guessing they are favourable otherwise there'd be no point.
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    Thread for new battery breakthrough PR releases

    If it managed 60 charge and discharge cycles in 120 hours that implies 1C charge and discharge rates. Given big enough capacity batteries, used in parallel, this could potentially extend the cycle time but it would still require long charging times.
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    Thread for new battery breakthrough PR releases

    It'll never take off like that but the proof of concept is nice. With some of the solid electrolyte battery techs floating around offering 2-3 times the energy density plus a dramatic increase in cycles...this seems like a 2 steps back one step forward scenario. For the way I use my ebike 60...
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    Thread for new battery breakthrough PR releases

    Well a battery stores energy electrochemically and a capacitor electrostatically. Some capacitors do use a chemical process too. Really they are both doing the same thing though, just differently. To radically increase the capacity of a capacitor you need to increase the surface area of the...
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    Thread for new battery breakthrough PR releases

    Surely once made though the neodymium magnets can be reused as many times as you want?
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    Thread for new battery breakthrough PR releases

    As far as I understand it the high reactivity of lithium, being very eager to give up an electron, is why it's especially suited to energy storage. Energy is volatile by its very nature and requires volatility in order to be stored. Lithium is eager to give up an electron, sodium is even more...
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    Thread for new battery breakthrough PR releases

    That stacked battery stuff is nice as a refinement of current lithium ion technology and has the potential, in the interim, until something truly revolutionary comes along. Current 18650s etc have the huge benefit of being modular. They can easily fit into a many number of OEM pack designs...
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    Powering 5V rear light from BBSHD shift sensor cable?

    I had mediocre lights and reflectors on my bike and people didn't see me. Then I upgrade to something more significant. 4 CREE XPE red LEDs mounted around the reflector and two MKR white at the front, all with suitable lenses. These aren't driven particularly hard for a total power consumption...
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