Talk:Ragone plot

Untitled

The 10 hours, 1 min, and 1 sec on the graph need to be explained. I am an engineer and i am uncertain myself what it indicates.

Specificity to energy storage?

Is this type of graph actually specific to comparisons of energy storage media? The example on this page reminded me of the diagrams that show the temperature and brightness of different types of stars, such as Media:H-R_diagram_-edited-3.gif. Whether the different categories are shown as blobs or as masses of data points, I'd consider to be a detail rather than a defining characteristic--so perhaps these are both examples of a more generic chart type. If so, then I think Ragone charts should be mentioned briefly on that page. If "Ragone chart" is the appropriate name for the generic chart type, then this article should be expanded. --Dzhim (talk) 20:03, 9 May 2009 (UTC)

We need a much better example of ragone chart.

Gasoline, jet fuel, fly wheels, hydrogen etc can be shown on a chart. And what do the times refer to? Very unclear, and no explanation offered as to what they are. —Preceding unsigned comment added by R Stillwater (talk • contribs) 23:07, 11 June 2009 (UTC)

I agree. The times should refer to diagonal lines that indicate the relative time to get the charge in or out of the device. There are some better examples at: http://www.mpoweruk.com/performance.htm#ragone and at http://www.mpoweruk.com/alternatives.htm; http://daedalus.caltech.edu/class/2007_aph150/notes/Lecture3a_Fultz.pdf; http://corrosion-doctors.org/Batteries/ragone.htm and in many other places. —Preceding unsigned comment added by 212.44.45.37 (talk) 09:41, 19 June 2009 (UTC)

Ragone Chart history

Who invented this chart, what is the history behind this chart? I think these are valid things to have in this page. Unfortunately i havn't found the answer to this yet. —Preceding unsigned comment added by 132.181.52.34 (talk) 05:07, 3 November 2009 (UTC)

This article is terrible

It says the vertical axis describes how much energy is available, but the units on the vertical axis aren’t energy, they’re energy per unit mass. Likewise, it says the horizontal axis shows power, but the units on the horizontal axis aren’t power, they’re power per unit mass. Without an explanation, this is going to confuse the average reader.

For a given energy storage device (say, an alkaline battery that weighs 0.4 kg), the mass is fixed, and the “per kg” portion of the units could be dropped. I think the only reason “per kg” is part of the units is to convey the concept that, for example, you could double the amount of available energy by using two such batteries connected in parallel, but you would also double the mass of the energy storage device, so the energy density remains unchanged. (Same goes for power density.)

But the article does a terrible job of conveying this concept.

For any given energy storage device (if I understand Ragone plots correctly), moving to the right on the plot represents discharging the device at a higher rate. But the article doesn’t explain that at all.

Also: the article contrasts a flashlight with a transistor, and says “these two devices would find themselves at opposite corners of the Ragone chart.” Actually, these two devices would never appear on a Ragone chart at all, because they’re not energy storage devices. They are electrical loads. GPS Pilot (talk) 00:39, 9 July 2011 (UTC)

With less typing that that, you could have changed the article. How is it now? --Wtshymanski (talk) 13:41, 9 July 2011 (UTC)

Different Types of Ragone Plot?

In the “Handbook of Energy Storage” by Sterner and Stadler (see source for full ref-info), </ref> the axes show different physical quantities. They used: Duration of discharge for y-axis and storage capacity for x-axis.

This gives similiar, but not identical information to the viewer.