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Batteroo testing
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Fungus:

--- Quote from: lpickup on December 21, 2016, 03:26:43 pm ---So given the dilemma of different viewpoints, one should be prepared to back their test procedure up with some kind of meaningful rationale why a particular viewpoint was chosen.

--- End quote ---

Or record longevity and number of laps. Add a lap counter to the train.


FrankBuss:

--- Quote from: Fungus on December 21, 2016, 02:43:31 pm ---I'm bothered by a lot of these tests.

eg. The train. If the train goes around the track faster with batteroo then they can declare it a "win" even if it only lasts half as long.

A better test might be "How many times does it go around the track?" and totally ignore the overall running time. It's less correct technically but I really think that "number of times around the track" would be a better set of numbers to show the public.

--- End quote ---

I thought about using a photodiode and an Arduino to count the laps and lap times, but the video is all you need, you can do it yourself, if you like. Would be a nice test for OpenCV.

The train test is done, pretty embarrassing for Batteroo :) Will make a nice video now and upload it.
razvanme:

--- Quote from: Fungus on December 21, 2016, 03:59:26 pm ---
--- Quote from: lpickup on December 21, 2016, 03:26:43 pm ---So given the dilemma of different viewpoints, one should be prepared to back their test procedure up with some kind of meaningful rationale why a particular viewpoint was chosen.

--- End quote ---
Or record longevity and number of laps. Add a lap counter to the train.

--- End quote ---

True, that basically means finding out the energy extracted from the battery, that energy can be extracted in different ways. Not saying it's not a good test.
I think we should also find some tests that anyone can support.
For example I think everyone can agree the more pictures a camera takes the better, there is nothing to say about that, you can't say it took them faster with batteriser than without, you can't pick sides depending on the test.
- Apple keyboard - key's pressed
- Pictures taken
- Movie length recorded

The test's can't be evaluated in different ways.

( The mp3 player is not part of those, you can have the time it plays AND the volume, two things to consider, not one )


--- Quote from: FrankBuss on December 21, 2016, 04:04:57 pm ---I thought about using a photodiode and an Arduino to count the laps and lap times, but the video is all you need, you can do it yourself, if you like. Would be a nice test for OpenCV.
The train test is done, pretty embarrassing for Batteroo :) Will make a nice video now and upload it.

--- End quote ---

Don't make us wait too long  :popcorn:
Fungus:

--- Quote from: FrankBuss on December 21, 2016, 04:04:57 pm ---I thought about using a photodiode and an Arduino to count the laps and lap times, but the video is all you need, you can do it yourself, if you like. Would be a nice test for OpenCV.

The train test is done, pretty embarrassing for Batteroo :) Will make a nice video now and upload it.

--- End quote ---

OTOH if it's embarrassed itself then no need for anything fancy.   :popcorn:

(Was the train actually going noticeably faster at any point?)
FrankBuss:
The camcorder needs ages to transfer the video, not the latest model.

But I could already create some data to create efficiency curves. TL;DR: the Python measurement script and the data.

This is the circuit I used for the electronic load:



The op-amp has a terrible offset and doesn't seem to be much linear, or I don't understand how to build it right, but it is short term stable and at least strictly monotonically increasing, so I could program a binary search in Python: The PSU channel 2 is set to 0 and step size to something big. Then the shunt voltage is measured with the Hameg multimeter. If it is lower than needed, the step is added. If it is higher, the step size is halved and subtracted, until the step size is reasonable small. Of course, after adjusting the current, the input voltage has to be adjusted again, too, because of losses in the uCurrent and wires, so that the exact desired voltage is at the Batteroo sleeve. The sleeve itself has 3 connections: input, output and ground. The idea from razvanme to use a metal strip from a 9V battery was excellent, I stuffed a battery with the sleeve in a solderable battery holder and the stripe connected to the Batteroo input, but isolating the plus terminal of the battery. So I didn't had to solder anything to the sleeve and the dummy battery acts as a heat sink, too. The input connection is then connected to the first PSU channel (after the uCurrent). The output is connected to the electronic load and ground is connected to ground. Each of the 3 connections have sense wires, which are connected to the analog mux and switched in pairs to the voltmeter.

That's not fast, but I don't care if it runs an hour. With this I could automate to measure all four values (input voltage, current and output voltage and current) for 0.6 V to 1.6 V input voltage, in 0.2 V steps, and for each voltage the load is stepped through from 10 mA to 100 mA (need a higher shunt for lower current, because the resolution gets too low, and a lower shunt for higher current). See the script for details (still a bit rough, just a quick hack).

I hope there is no bug and the numbers are right, will verify some samples tomorrow with my multimeter manually, but it is consistent with the train test. Now finishing the MP3 player test. The setup looks a bit crazy, but I've labelled all wires on an extra patch board, so that I don't get confused :)


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