EEVblog #779 - Batteriser: How To Measure Battery Cutoff Voltage

Another in a series of battery tutorials, Dave explains how to correctly measure the battery cutout voltage of a product.
And how to take internal resistance of a battery into account.
And also a detailed response to a video from Batteriser claiming Dave is wrong in using a PSU to measure the battery cutoff voltage, and why this is complete folly.
The Batteriser videos:
and

Battery Ionic Resistance video:
Inside a 9V battery video:

Full playlist of battery related videos is here:

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[Thesignalpath]

Dave, I think you are doing the best thing you can do. Scientific response to unscientific claims.

[Afrotechmods]

I just went to Batteriser's Youtube channel and saw related channels: EEVBlog and EEVBlog2. Epic.

[darrenjacobson]

It's pretty obvious how bullshit this is. They tested the power supply under load and then compared it to batteries they tested open circuit. That isn't even a fair comparison. But for anyone who still isn't sure who to believe in this argument, consider the participants. On one side you have a qualified and experienced electrical engineer, who has made a career out of educating people on the net (among other things). On the other side, you have a company trying to sell you a product... Enough said.

[onjofilms]

Sorry Dave, I believe Batteriser because they use professional voice over artists and have uplifting music in the background. (j/k :))

[vwestlife]

The Batteriser Batteroo "fan page" channel just posted an announcement saying: "Pls stand by we are in a process of releasing a video with the technical explanation for all engineers on how Batteriser works, while at first glance, it seems implausible, I am sure that real genuine engineers will appreciate our whiteboard technical discussions along with simulation, data matching battery companies spec sheets, in conjunction with device data. Of course, those whose revenue will be reduced by our technology will do everything to divert attention"

[jastervoid]

Dave's exasperated noises are the best part of this video. 10/10

[WhitentonMike]

EEVblog There is also the misleading way they tested the product load. With the power supply they started the product and got it running and then lowered the voltage, then with the partially drained batteries they attempted to start the product cold from a dead stop. DC motors require more current to startup than when they are already running. So it is no surprise that even 0.9V would likely not allow the product to start. So they are comparing apples to oranges since with the power supply they did not start out at 0V and slowly up it until the product started. It will most certainly require more current to overcome the static friction of the product.

[LazerLord]

When a company is using dislikes bots and/or paying to dislike a video, you just _KNOW_ they're doing something right.


*_*Facepalm_*

[BrantM]

Dave, I think you should have pointed out that the monkey doesn't even *have* a cutoff voltage like a wireless keyboard or whatever. Judging by the fact that they took it down to .9V I'd say there's only a brushed DC motor in there. Not a single scrap of circuitry to detect voltage.

Also interesting that all the devices they showed on their video were motor driven, and likely didn't have cutoff voltages either. I'd say that was clever, but I don't think they're smart enough to do clever.

ESR and other factors aside, claiming a DC motor has a hard cutoff like a digital device is what got me. It's just so bafflingly stupid, and I really can't decide if they did it on purpose or not.

[gogo]

This just shows, how world of marketing works. Deliberately using false or misleading arguments to make the less informed customer to buy the $h1t they have to sell. That's sick! Thank you, Dave, for your efforts in this particular case.

[alexanderhiller]

I just caught them making posts on their own page. Some yahoo named "Brad Jones" commented that this product was amazing, etc etc., and then claiming he was an engineering student and that he wanted an internship for this amazing product! Well, I told him to have the University give him his money back and then cited a few obvious glitches with the logic while and then tagged the Batteriser folks.... Instead of Batteriser Replying, Brad Jones Replied with 
Brad Jones
+Alexander Hiller hey stupid. are you illiterate? we are business, econ, acct, and phycology majors here at the community fan page. We send your questions to the engineers on the Batteriser team. I already mentioned several times.
Directly from the CEO to us here at the fan page "Pls stand by we are in a process of releasing a video with the technical explanation for all engineers on how Batteriser works, while at first glance, it seems implausible, I am sure that real genuine engineers will appreciate...
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He obviously forgot to log back into Batteriser before replying to me. What a bunch of FAKES! I screenshotted everything as well if anyone wants the convo.

[GoldSrc_]

I just laughed at their square wave, I mean come on, if you're going to fake something don't leave dumb mistakes like those lol.

[GiGaSzS]

My head hurts from the "misleading" videos from Batteriser!
But thank you Dave for explaining it to those who weren't sure about it.
Batteriser monkey test is also not done correctly as they didn't have it in the same position (more or different force on a motor).
Anyway, looking forward for battery tests and characteristics Dave is doing :)

[thesnowedone]

Wow - I can't believe they posted that video that's just.. I mean I'm not an electronics person and even I know the test they did was stupid.

[xwolpertinger]

The virgin soldering iron reminds me in those creationist videos of old where people in pristine lab coats give presentations in a studio.
That'll get you banned from the lunch counter than anything else, incidentally.

[ramueller]

LMAO, such an amusing video especially the analysis of the "lab" at 21:00. Thanks Dave!

When the monkey stalls, it draws 0.8 A to run the device at 0.9 V, for an apparent resistance of 1.1 ohm. Back of the envelope calculations reveal the battery voltage would have been around 0.87 V ~< 0.9 V ( 2.46 V x 0.6 Ohm / 1.7 Ohm ). It's pretty close if you consider ESR. However, I don't think they proved the PS test invalid, just as everyone would have guessed mostly because they didn't bother measuring the voltage at the terminals. However, another major flaw of their argument is that they did not prove you can startup the toy at 0.9 V.

[SproutyPottedPlant]

Thurs is fantastic entertainment! I was laughing along with you! I especially like the oscilloscope part!

[seanmcmunn]

This has been a great series, debunking bullshit products by simply explaining the science is wonderful to watch

[MichelSatoer]

You should add the word "Batteriser" to the title Dave. This way this video pop's up when people are searching for it.
Stil wondering if these Batteriser guy's also tested their monkey toy with the depleted batteries and their magic Batteriser.

[LancePickup]

I love how all the suggested auto-load videos at the end of their videos come up with your debunking videos Dave!