5 ms·

Imagine these batteries in Teslas, that will mean a full charge in about ~10 minutes, which could potentially make all gasoline cars lame.

by alisnic 12y ago

tormeh 12y ago
This. We have electric engines pinned down. All that's missing from unlimited application of energy is better batteries and better power generation. Look at it this way: Human endeavor consists of intelligent application of energy to mass. One of the three elements are close to being made trivial! It's very easy to get excited about batteries and renewable energy!
- baq 12y ago
  this is not that simple. the article claims that density is similar to lithium batteries, but it doesn't say what kind of density is it. the fact that it charges 20x as much may mean naught if it holds 1/20 energy per kg or per liter.
  - barrkel 12y ago
    Direct quote from the article: This unique battery offers energy density comparable to a lithium ion battery I have no idea about how credible its claims are.
  - StavrosK 12y ago
    What do you mean "what kind of density"? "Similar to lithium batteries" means just that, if you have a lithium battery of a certain size, this will hold an amount of energy similar to that.
    - Tuna-Fish 12y ago
      Energy density can be given in terms of mass or in terms of volume. In general, if a source of a new interesting battery technology does not describe which one they mean in a comparison, you can assume the worst, that is, that they are comparable to lithium-ion in joules/m^3 (at which lithium ion isn't actually that good).
    - marvin 12y ago
      A 30% difference would still be classified as "similar", but this would still be a big deal since batteries are just borderline capable to provide electric cars with sufficient charge to be acceptable for most people. A battery that's 30% worse than the best current batteries would be unusable.
      - selectodude 12y ago
        A car that could charge in 5 minutes and go 200 miles would be as useful to me as my current car. It's a start.
        ctdonath 12y ago
        He's referring more to a car that could charge in 5 minutes and go 60 miles. As I have an EV, that's closer to my current scenario of charging (once they put in a charger in the office parking lot) 4 hours and going 90 miles. The tradeoff of reduced distance for superior charge time is...irritating.
        selectodude 12y ago
        60 miles would be just short enough where I would need a gasoline car. That's why I've yet to get a Leaf. Can't afford a Tesla (nor do I want/need a car that big).
        deleted 12y ago
        [deleted]
  - tormeh 12y ago
    I meant about the space in general. Sorry about the confusion. I've edited my post.
Tuna-Fish 12y ago
Except that you also have to move the electricity into the car, which is actually the limiting factor in Teslas today, not the batteries. So this wouldn't really help at all.
- danmaz74 12y ago
  Source?
  - marvin 12y ago
    Just read up on any existing quick-charging technology. Tesla's superchargers are the world's highest-capacity quick charging at 130kW, 2x the nearest competitor (CHAdeMO). And this still requires ~one hour to give the battery a full charge. Let's say you want to be able to charge in six minutes. That would mean something on the order of 1.3MW of electric power. So let's say you have a small-ish refueling station like a contemporary gas station, with eight charging spots. To power these, you need to pull ten megawatts from somewhere. The current power grid isn't dimensioned for this kind of demand, especially since the demand is very transient. Tesla is attempting to solve this by building a massive battery storage capacity into the chargers and then trickle charging these batteries when the charging bays are not in use, so this is by no means a problem that has been solved once and for all.
    - snowwindwaves 12y ago
      Distribution level voltage is anywhere from 4kv to 25 kv. Say it's 12. Typical partridge or linnet distribution conductor might do 200 A. P=sqrt(3)IV cos theta = 1.73 * 200 * 12000 * 0.9 = 3.7 mw. So you are correct your average distribution feeder probably does not have capacity for a 10 mw service. I guess that's not much of a shock.
      - CapitalistCartr 12y ago
        In the United States the normal distribution voltage, prior to being stepped down for consumer use, 7.6kv phase to ground, 13.2 phase to phase. So yes, you're pretty close, except the 13.2 kv would be 3-phase. For heavy industrial use, 4.4 kv is common for actual end user equipment, but above that would be some pretty serious equipment for an end user. Larger transmission lines operate anywhere from 60kv on up to 1.1 million volts, so lots of power is possible, as long as you don't mind the brownouts.
loceng 12y ago
AFAIK it currently takes ~20 minutes to half-charge a Tesla. 20x would mean charging fully in ~2 minutes - nearly as fast as the automatic option for replacing depleted batteries with fully charged ones.
- masklinn 12y ago
  > 20x would mean charging fully in ~2 minutes Charge profile is not linear in existing batteries. A supercharger is 40mn to 80% and 75mn to 100%.
  - loceng 12y ago
    Ah, good to know - thank you.
  - danielweber 12y ago
    How does a quick-charge affect the longevity of the batteries?
    - mikeash 12y ago
      I don't believe it's known yet. Battery longevity seems to involve a lot of trial and error, and there isn't much data. As far as I've been able to gather (and I have no real special knowledge here and could be way off), the main problem with quick charging is that it heats the batteries a lot, since charging is not a 100% efficient process and any waste energy turns into heat. Heat is bad for batteries, so it could affect their life. However, Teslas have active temperature management for their batteries (both heating and cooling, as required) which should mitigate that.
    - mnw21cam 12y ago
      Not sure for LiIon batteries. However, back in the days of NiCad batteries, some formulations could cope with really fast charges - and in fact would behave better and last longer after a very fast charge than they would after a slow charge. We're talking about shoving 20 amps into a C cell for five minutes here. You needed to carefully monitor the cell temperature - the charging process wouldn't generate much heat until the cell was nearly full, at which point nearly all the energy going in would convert to heat. 20 amps would heat a full C cell up very quickly indeed.
cLeEOGPw 12y ago
Except that it doesn't take 10 minutes to fill a gas tank and you can go 1000 km with full, unlike Tesla.

Imagine these batteries in Teslas, that will mean a full charge in about ~10 minutes, which could potentially make all gasoline cars lame.

by alisnic 12y ago

Imagine these batteries in Teslas, that will mean a full charge in about ~10 minutes, which could potentially make all gasoline cars lame.

tormeh 12y ago

This. We have electric engines pinned down. All that's missing from unlimited application of energy is better batteries and better power generation. Look at it this way: Human endeavor consists of intelligent application of energy to mass. One of the three elements are close to being made trivial! It's very easy to get excited about batteries and renewable energy!

baq 12y ago
this is not that simple. the article claims that density is similar to lithium batteries, but it doesn't say what kind of density is it. the fact that it charges 20x as much may mean naught if it holds 1/20 energy per kg or per liter.
- barrkel 12y ago
  Direct quote from the article: This unique battery offers energy density comparable to a lithium ion battery I have no idea about how credible its claims are.
- StavrosK 12y ago
  What do you mean "what kind of density"? "Similar to lithium batteries" means just that, if you have a lithium battery of a certain size, this will hold an amount of energy similar to that.
  - Tuna-Fish 12y ago
    Energy density can be given in terms of mass or in terms of volume. In general, if a source of a new interesting battery technology does not describe which one they mean in a comparison, you can assume the worst, that is, that they are comparable to lithium-ion in joules/m^3 (at which lithium ion isn't actually that good).
  - marvin 12y ago
    A 30% difference would still be classified as "similar", but this would still be a big deal since batteries are just borderline capable to provide electric cars with sufficient charge to be acceptable for most people. A battery that's 30% worse than the best current batteries would be unusable.
    - selectodude 12y ago
      A car that could charge in 5 minutes and go 200 miles would be as useful to me as my current car. It's a start.
      - ctdonath 12y ago
        He's referring more to a car that could charge in 5 minutes and go 60 miles. As I have an EV, that's closer to my current scenario of charging (once they put in a charger in the office parking lot) 4 hours and going 90 miles. The tradeoff of reduced distance for superior charge time is...irritating.
        selectodude 12y ago
        60 miles would be just short enough where I would need a gasoline car. That's why I've yet to get a Leaf. Can't afford a Tesla (nor do I want/need a car that big).
      - deleted 12y ago
        [deleted]
- tormeh 12y ago
  I meant about the space in general. Sorry about the confusion. I've edited my post.

Tuna-Fish 12y ago

Except that you also have to move the electricity into the car, which is actually the limiting factor in Teslas today, not the batteries. So this wouldn't really help at all.

danmaz74 12y ago
Source?
- marvin 12y ago
  Just read up on any existing quick-charging technology. Tesla's superchargers are the world's highest-capacity quick charging at 130kW, 2x the nearest competitor (CHAdeMO). And this still requires ~one hour to give the battery a full charge. Let's say you want to be able to charge in six minutes. That would mean something on the order of 1.3MW of electric power. So let's say you have a small-ish refueling station like a contemporary gas station, with eight charging spots. To power these, you need to pull ten megawatts from somewhere. The current power grid isn't dimensioned for this kind of demand, especially since the demand is very transient. Tesla is attempting to solve this by building a massive battery storage capacity into the chargers and then trickle charging these batteries when the charging bays are not in use, so this is by no means a problem that has been solved once and for all.
  - snowwindwaves 12y ago
    Distribution level voltage is anywhere from 4kv to 25 kv. Say it's 12. Typical partridge or linnet distribution conductor might do 200 A. P=sqrt(3)IV cos theta = 1.73 * 200 * 12000 * 0.9 = 3.7 mw. So you are correct your average distribution feeder probably does not have capacity for a 10 mw service. I guess that's not much of a shock.
    - CapitalistCartr 12y ago
      In the United States the normal distribution voltage, prior to being stepped down for consumer use, 7.6kv phase to ground, 13.2 phase to phase. So yes, you're pretty close, except the 13.2 kv would be 3-phase. For heavy industrial use, 4.4 kv is common for actual end user equipment, but above that would be some pretty serious equipment for an end user. Larger transmission lines operate anywhere from 60kv on up to 1.1 million volts, so lots of power is possible, as long as you don't mind the brownouts.

loceng 12y ago

AFAIK it currently takes ~20 minutes to half-charge a Tesla. 20x would mean charging fully in ~2 minutes - nearly as fast as the automatic option for replacing depleted batteries with fully charged ones.

masklinn 12y ago
> 20x would mean charging fully in ~2 minutes Charge profile is not linear in existing batteries. A supercharger is 40mn to 80% and 75mn to 100%.
- loceng 12y ago
  Ah, good to know - thank you.
- danielweber 12y ago
  How does a quick-charge affect the longevity of the batteries?
  - mikeash 12y ago
    I don't believe it's known yet. Battery longevity seems to involve a lot of trial and error, and there isn't much data. As far as I've been able to gather (and I have no real special knowledge here and could be way off), the main problem with quick charging is that it heats the batteries a lot, since charging is not a 100% efficient process and any waste energy turns into heat. Heat is bad for batteries, so it could affect their life. However, Teslas have active temperature management for their batteries (both heating and cooling, as required) which should mitigate that.
  - mnw21cam 12y ago
    Not sure for LiIon batteries. However, back in the days of NiCad batteries, some formulations could cope with really fast charges - and in fact would behave better and last longer after a very fast charge than they would after a slow charge. We're talking about shoving 20 amps into a C cell for five minutes here. You needed to carefully monitor the cell temperature - the charging process wouldn't generate much heat until the cell was nearly full, at which point nearly all the energy going in would convert to heat. 20 amps would heat a full C cell up very quickly indeed.

cLeEOGPw 12y ago

Except that it doesn't take 10 minutes to fill a gas tank and you can go 1000 km with full, unlike Tesla.