No matter how you look at it, Batteriser means a LOSS in overall power.
First, Dave's calculation assumes that there is no energy available once the voltage under load reaches 0.8 volts. Presumably, if we had a load with a dropout voltage lower than 0.8, we could draw a small amount of extra energy beyond what the calculation considers to be 100% --- it's pretty clear that the discharge curve becomes close to vertical, however, so this extra energy is pretty much negligable.
This is why the manufactures usually don't provide curves below 0.8, it is the defacto industry standard dropout voltage at which point any extra energy in the battery is consider negligible. As I mentioned in the video, there is some energy left below 0.8V for really small currents, and this is why a joule thief can flash a LED down to bugger all. Very small amount of energy, very niche applications where it can be used.
I didn't want people thinking they should go to the ends of the earth to design products with a 0.5V cutout voltage, that's rarely done in the industry.
I'd like to see constant current and constant power discharge curves down to zero volts. It would be interesting to see how much more energy a germanium (for example) based device can use. Or a device that uses two batteries in series, but cuts out at 0.8V.
However, I do not have the necessary equipment to do it.
No matter how you look at it, Batteriser means a LOSS in overall power.
If there is no significant energy below 0.8V then you don't have to go to 0V. What I did was correct when you assume (as is industry standard practice to do) there is zero usable energy below 0.8V.
The numbers come out exactly the same regardless of whether you include all the way down to 0V or just down to 0.8V. Those who are unsure about this need only try it.
I'd like to see constant current and constant power discharge curves down to zero volts. It would be interesting to see how much more energy a germanium (for example) based device can use. Or a device that uses two batteries in series, but cuts out at 0.8V.
However, I do not have the necessary equipment to do it.
I cannot do it to zero, but to 0.3 volt with 0.1 watt constant power:
All the spikes is because I pauses the discharge 1 minute every 10 minutes to see the unloaded voltage. I.e. my time scale is 10% to long.
If I had held a longer pause the cell would have recovered more voltage.
Here is a zoom of the last part of the above curve:
No matter how you look at it, Batteriser means a LOSS in overall power.But what if you stick it on only after the device turns off because of low battery voltage?
you really flunked it, sorry!
As others already mentioned, you did not show the power integral area correctly, i.e. from 0.8 to the discharge line only, instead of zero volt to the discharge line.
That is really annoying, and may disturb students, for whom this video is intended for, obviously.
that could have been a nice educational video, but you really flunked it, sorry!
As others already mentioned, you did not show the power integral area correctly, i.e. from 0.8 to the discharge line only, instead of zero volt to the discharge line.
That is really annoying, and may disturb students, for whom this video is intended for, obviously.
It could also have been very easy to bust the rest out of the residue energy myth, by discharging the battery to its very limits, below 0.8V, as these energy saver gadgets claim to operate well below that voltage.
It's a pity you missed that chance.
This video was very informative, as always, but the videos where you talk while doing screen capture of your computer screen can be a little boring. Have you ever considered setting up a camera and recording yourself while you talk? Then you can do either a picture in picture shot where your talking head is in the corner of the screen, or you can cut back and forth between you and your computer screen. Doing either of those, or a combination, would make your screen capture videos more entertaining. Sorry if this has already been brought up before, but I don't spend much time on the forums. Keep up the great work.
This video was very informative, as always, but the videos where you talk while doing screen capture of your computer screen can be a little boring. Have you ever considered setting up a camera and recording yourself while you talk? Then you can do either a picture in picture shot where your talking head is in the corner of the screen, or you can cut back and forth between you and your computer screen. Doing either of those, or a combination, would make your screen capture videos more entertaining. Sorry if this has already been brought up before, but I don't spend much time on the forums. Keep up the great work.
As others already mentioned, you did not show the power integral area correctly, i.e. from 0.8 to the discharge line only, instead of zero volt to the discharge line.
That is really annoying, and may disturb students, for whom this video is intended for, obviously.
The numbers come out exactly the same.
you really flunked it, sorry!
As others already mentioned, you did not show the power integral area correctly, i.e. from 0.8 to the discharge line only, instead of zero volt to the discharge line.
That is really annoying, and may disturb students, for whom this video is intended for, obviously.
? So all the battery companies do it wrong as well? If there's a STEM student who can't add or subtract a rectangular area from an integral... Oh who cares? Somebody has to drag down class averages I suppose.
I thought the presentation was perfectly clear. Maybe those unhappy souls who don't "get" it should ask for refunds.
And I thought the 0.8V cutoff was also to prevent battery leakage.
If you thought the presentation was perfectly clear can you also disclose what level of understanding you had prior?
It was a good video, and well presented but clearly some people without a solid engineering understanding of the topic still have questions. Brushing them aside with "Oh who cares? Somebody has to drag down class averages I suppose." may suit your ego but not much else. I am glad Dave is prepared to share his knowledge for the benefit of others. In any event what is the point of an educational video to people who understand the topic?
If some "unhappy souls" still have questions, what is wrong with asking them? If it appears enough need further explanation Dave may recognize an opportunity to do a follow-up. I'm pretty sure he said he was going to get some Batterisers and test them out. It is no bad thing to have his audience well informed beforehand. And since he likes drawing graphs and analysing data it's a win all around.
I assume you mean something other than that the apparent capacity remaining that one would get from integrating from 0.8V to the discharge line only would not differ from that if you instead integrated from 0 volts to the discharge line. In other words, the difference between measuring the "area under the curve" with the area's base at 0.8 V instead of the area's base at 0 V. Because, there is actually a substantial difference.
I assume you mean something other than that the apparent capacity remaining that one would get from integrating from 0.8V to the discharge line only would not differ from that if you instead integrated from 0 volts to the discharge line. In other words, the difference between measuring the "area under the curve" with the area's base at 0.8 V instead of the area's base at 0 V. Because, there is actually a substantial difference.
Nope, see attached.
I've been getting the feeling that in this group, saying that there is more energy left than looking at the (wrong) area suggests, makes me look like I am trying to support Batterizers (sp?) claims --- I'm not. The numerical calculations that Dave made (with the spreadsheet), are (I think) correct, and the unbiased visual depiction of the areas under the discharge curve would support them.