| EEVblog > EEVblog Specific |
| EEVblog #751 - How To Debunk A Product (The Batteriser) |
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| Poe:
--- Quote from: Wytnucls on June 07, 2015, 10:49:30 am ---The curve published by Duracell for 100mW is much flatter and goes below 0.8V. At 1V, the load will draw 100mA and 170mA at the claimed 0.6V threshold, to maintain that power. 10 to 20% battery life extension seems plausible at that power level. --- End quote --- It's a shorter graph, but I'm not so certain those lines are flatter. Since the internal resistance increases as the battery is discharged, the cutoff voltage is a function of how much current you're pulling. |
| calzap:
--- Quote from: ez24 on June 06, 2015, 07:24:39 pm ---1. What's the going rate for a professor? In the 70s one asked me for $2000 (under the table) in order for me to sell my product at his school and I did not want to pay it, so I lost my business. And to be honest to this day, I wonder where I would be if I had paid him the money. Professors are people and like people, some can be bought. --- End quote --- As a retired professor, I can attest that with regard to ethics, there is a broad spectrum in the academic ranks. Actually, the majority are quite ethical. Most common conflict is requiring their students to buy a textbook that they wrote. At the least, they should refund the royalty per textbook to each of their students who buy it. Some are for sale to do endorsements. Usually these are more senior profs who have a reputation in their field, so are attractive endorsers for companies. And being tenured, they don't have to be too concerned about the opinion of their colleagues and department head. Some naive young (and not so young) profs get suckered into doing endorsements without realizing how it will be used for marketing. Happened to me as an assistant prof. There was a commercial analytic lab that contacted me suggesting that my lab and theirs compare results on some samples. I agreed. The results were very close, and I sent them a letter stating that was the case. A few weeks later, quotes from my letter appeared in their ads. Learned to be careful after that. Mike in California |
| Wytnucls:
I just finished running a discharge test of a single Duracell AA battery, between 0.7V and 0.6V, with a constant resistive load (5.6 Ohms + test leads). Initial discharge current was 100mA and at the end, 90mA. It took 1 hour and 5 minutes for the 0.1V discharge. Assuming the discharge slope is constant between 1V and 0.6V, that would be 4 hours of extra battery time. Depending on the converter efficiency at 100mA, that time could be reduced significantly. Those figures seem to tie up with the Duracell graph. There doesn't seem to be any significant rise in internal battery resistance above 0.6V. Test jig: Keithley 2000 measuring voltage, Rigol DM3058E measuring current on 2A range and 10W 5.6 Ohm resistor. |
| Mybetoostnedforths:
Hi from Sweden! I just thought of something crazy aight. Consider this If applying the gizmo to your battery provides constant voltage at 1.5, by converting the stuff. And if as Dave says, screws up battery-indicators, wouldn't that mean that the indicator would just go to 100% (as in 1.5 volt), making it seem like it's full? As seen in their marketing video at 26 seconds. That'd fool consumers into thinking it actually works, since it's full. Atleast for a while. But hell, I'm just a very-low-time electronics hobbyist, and I sure as hell could just be wrong. Regards Mybetoostnedforths |
| 0xdeadbeef:
--- Quote from: Wytnucls on June 07, 2015, 07:26:02 pm ---I just finished running a discharge test of a single Duracell AA battery, between 0.7V and 0.6V, with a constant resistive load (5.6 Ohms + test leads). Initial discharge current was 100mA and at the end, 90mA. It took 1 hour and 5 minutes for the 0.1V discharge. Assuming the discharge slope is constant between 1V and 0.6V, that would be 4 hours of extra battery time. Depending on the converter efficiency at 100mA, that time could be reduced significantly. --- End quote --- Well, 1st of all 400mAH is 20% of a 2000mAH cell. Not quite 800%. Also keep in mind that even at ideal efficiency, the boost up of the voltage to 1.5V means that 100mA drawn from the boost up converter doesn't mean 100mA are drawn from the battery. Actually, at 0.7V more than 200mA are drawn which raises to 250mA at 0.6V. Obviously, considering a realistic efficiency, the current would be even higher. And higher currents means negative impact on battery life. |
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