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planet4ever
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Re: Range-Speed-Bars Thumb Rule Table

Mon Aug 15, 2011 2:52 pm

drees wrote:
planet4ever wrote:But you are suggesting more than 10% loss in (stored energy) - (recovered energy), which seems astonishingly high to me. All that "lost" energy must be converted to heat, no? Since the LEAF battery has no active cooling, I would think that would make it heat up rapidly under load, such as when climbing a mountain. Why has no one reported this?
Because that heat isn't lost in the batteries - it's lost in the inverter and motor. Basically the LEAF's batteries have an extremely low internal resistance.
Gary puts inverter and motor losses losses in a different category: (recovered energy) - (motor energy). So, drees, you are also suspicious of a 10%+ loss in the battery.

Ray
End of April 2013: Traded my 2011 SL for a 2013 S with charge pkg.

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DaveEV
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Re: Range-Speed-Bars Thumb Rule Table

Mon Aug 15, 2011 4:01 pm

planet4ever wrote:
drees wrote:
planet4ever wrote:But you are suggesting more than 10% loss in (stored energy) - (recovered energy), which seems astonishingly high to me. All that "lost" energy must be converted to heat, no? Since the LEAF battery has no active cooling, I would think that would make it heat up rapidly under load, such as when climbing a mountain. Why has no one reported this?
Because that heat isn't lost in the batteries - it's lost in the inverter and motor. Basically the LEAF's batteries have an extremely low internal resistance.
Gary puts inverter and motor losses losses in a different category: (recovered energy) - (motor energy). So, drees, you are also suspicious of a 10%+ loss in the battery.
No - I think his numbers are way off. Stored energy is too high. Direct charge/discharge efficiency is only a percent or two at most at the battery level. The big losses are in the inverters and motor.

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evnow
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Re: Range-Speed-Bars Thumb Rule Table

Mon Aug 15, 2011 4:31 pm

Herm wrote:I think evnow should just buy a module at the dealership and put us out of our misery. He's rich anyways..
LOL. You really thought I didn't get the Roadster because of the small trunc ? ;-)

I think the important thing to note is that 21 kwh is what the battery capacity "seems" to be - when considering the m/kwh displayed by the Leaf dash.

In practice that is what matters - if you multiply the m/kwh by 21 - you get close to the range. So, the figure 21 helps us figure out the range ...

"Actual usable" capacity may or may not be different. At this point, I couldn't care less about it.
1st Leaf : 2/28/2011 to 5/6/2013
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surfingslovak
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Re: Range-Speed-Bars Thumb Rule Table

Mon Aug 15, 2011 4:51 pm

evnow wrote:"Actual usable" capacity may or may not be different. At this point, I couldn't care less about it.
Precisely. It would good if we could coalesce around a usable battery model. It may not be accurate, but as long as it provides practical range predictions, it would be quite useful. Would it perhaps make sense to start a new thread on that or should we continue here?

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TonyWilliams
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Re: Range-Speed-Bars Thumb Rule Table

Mon Aug 15, 2011 5:27 pm

surfingslovak wrote:
evnow wrote:"Actual usable" capacity may or may not be different. At this point, I couldn't care less about it.
Precisely. It would good if we could coalesce around a usable battery model. It may not be accurate, but as long as it provides practical range predictions, it would be quite useful. Would it perhaps make sense to start a new thread on that or should we continue here?

I think many / most of us frequent forum participants already are comfortable with 21. Sure, it may be 21.4, or 21.6, but for the purpose of hitting a target miles/kWh number, it works.

What different battery model do you have in mind?

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surfingslovak
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Re: Range-Speed-Bars Thumb Rule Table

Mon Aug 15, 2011 5:50 pm

TonyWilliams wrote:I think many / most of us frequent forum participants already are comfortable with 21. Sure, it may be 21.4, or 21.6, but for the purpose of hitting a target miles/kWh number, it works.

What different battery model do you have in mind?
Yes, 21kWh works very well to predict total range. However, we have more data points now. Some of use are counting bars, others have an SOC meter from Gary or use your table and their speed to predict range. It would be nice if we could tie it all together.

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TonyWilliams
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Re: Range-Speed-Bars Thumb Rule Table

Thu Aug 18, 2011 4:12 pm

surfingslovak wrote: Some of use are counting bars, others have an SOC meter from Gary or use your table and their speed to predict range. It would be nice if we could tie it all together.

We will get there, I think!! My next project is a simple app that would key in many of the key ingredients to predict range... but that's another thread. I'll post that up later.

Here's my latest revision, #5, to the range chart. Like always, I appreciate critiques to make it better. The biggest change is that about 12.5 mph is the best range speed.

Everybody FORGET 38 MPH !!!

Tony

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TomT
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Re: Range-Speed-Bars Thumb Rule Table

Thu Aug 18, 2011 4:18 pm

Now if there was only some place that one could actually DRIVE at 12.5 mph without dying! :lol:
TonyWilliams wrote:The biggest change is that about 12.5 mph is the best range speed. Everybody FORGET 38 MPH !!!
Leaf SL 2011 to 2016, Volt Premier 2016 to 2019, and now:
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TonyWilliams
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Re: Range-Speed-Bars Thumb Rule Table

Thu Aug 18, 2011 4:54 pm

mogur wrote:Now if there was only some place that one could actually DRIVE at 12.5 mph without dying! :lol:
Fiesta Island, San Diego!!! I had old folks on bicycles passing me. Wind surfers, too.

The fuel bars are centered between the possible range with each bar. The previous charts did not reflect that.

If I jump in the car, and see 10 fuel bars, how do I know how much of that eFuel has been burned? I don't. That 10th bar may have 72 miles, or 66 miles remaining (at 60 mph). We don't know, and now the chart now better reflects that.

If you're driving along at 60 mph, and watch the 10th fuel bar disappear, now you know you have 66 miles from that point.

LEAFfan
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Re: Range-Speed-Bars Thumb Rule Table

Thu Aug 18, 2011 5:41 pm

TonyWilliams wrote:Here's my latest revision, #5, to the range chart. Like always, I appreciate critiques to make it better. The biggest change is that about 12.5 mph is the best range speed.
You're saying your results aren't based on 'dash data'? But I had thought we've proven that the dash/console data is similar to what you have found. When I went 15 miles at a steady 15 mph and the console showed 9.1 (prob 9 on the dash if it would go farther) I know I could have gone 200 miles if I had kept going (21 X 9.5 = 200m). Every so many miles that I went, the m/kW h meter kept going higher. So who knows where it would have been after another 15 miles? As soon as someone figures out how to 'fix' the CC, I'll prove it with the odometer.
2013 LEAF SV Del. 2/28/13
2013 LEAF World Record for Most Miles Driven On One Charge-188 miles/8.8 m/kW h
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