World's first real Free Energy Flashlight - no shaking - no batteries! No Solar

[skywatcher]

Update:

18.02.16    00:00:00    260       
               
                                     t=30sec    t=60sec    t=90sec
18.02.16    19:00:00    1280         1090         963
19.02.16    19:00:00    1770         1460        1260

The value for 'fully charged' would be > 28000.

Looks not so bad...  but i don't know it it's only 'bounce' or if it has gained some charge...  i think we have to wait some days to come to a conclusion.

[txt]

Looks not so bad...  but i don't know it it's only 'bounce' or if it has gained some charge...  i think we have to wait some days to come to a conclusion.

Well, I expected around 1500 lux with the battery rebounce after longer rest, but there are too many factors to guess it precisely, and the margin of error of the measuring is also unknown, so I would tell it is the expected value, and it should be around the same, or again just a bit higher tomorrow (it will be after almost 70 hours of rest, with just 3 minutes of very tiny discharge current in that time). If the thing truly self-recharged, I would expect the increase of minimally 10% of the maximum value - increase of some 3000 lux (it measn around 4000 lux at the beginning). But realistically, if there was any charging current, the charging curve of all batteries is very steep at the beginning and flattens to the end of the charging cycle, so within the first day, the charge of up to 50% would be more expected

[skywatcher]

Well, I expected around 1500 lux with the battery rebounce after longer rest, but there are too many factors to guess it precisely, and the margin of error of the measuring is also unknown, so I would tell it is the expected value, and it should be around the same, or again just a bit higher tomorrow (it will be after almost 70 hours of rest, with just 3 minutes of very tiny discharge current in that time). If the thing truly self-recharged, I would expect the increase of minimally 10% of the maximum value - it means increase of some 3000 lux (it measn around 4000 lux at the beginning). But realistically, if there was any charging current, the charging curve of all batteries is very steep at the beginning and flattens to the end of the charging cycle, so within the first day, the charge of up to 50% would be more expected

We don't know if the recharging process (if any) is 'constant current' or anything else. So we can only make some predictions based on known battery charge process and compare it with the measurements of the next days. Tomorrow we will see if the brightness curve is linear, or if it's above or below of the linear extrapolation. Because we measure only the brightness we can not say much about actual values of voltage, current etc.

[e2matrix]

Most Smartphones can work as a Lux meter - you just grab any one of several apps off the play store and you will have a fair Lux / Lumen meter.   It's how most smart phones determine auto-screen brightness and when to blank the screen while you are holding it to your head talking.

[txt]

EDIT: sorry, I did not notice the post above, when writing mine, so I repeat it partially below!

BTW, as it was already written, other owners who are currently testing their ELFE flashlights, like TheCell or Esaruoho, should definitely consider measuring the light brightness with something else than the naked eye, because Skywatcher's own experience clearly shows that even a very steep and deep change is hard to spot by the naked eye. If you do not want to spend money on a luxmeter like Skywatcher did, you can use a DSLR camera, many compact cameras, or even a phone luxmeter application. The following short video tutorial demonstrates how to use a DSLR camera for taking the illumination values. You will find many more descriptions for such proceedings on the web if you search for "measuring lux" and "camera" or similar terms. This is the video tutorial:

https://www.youtube.com/watch?v=_xU0pWjugTo

The measuring by a DSLR camera may be a bit more reliable. The absolute accuracy of phone sensors is questionable, but it should be fine for the approximate comparison of the flashlight in different periods of the test, and definitely much more objective than the naked eye, or than comparing photos or video frames. You should only try to keep the level of the environment light as constant as possible, or measuring in contact with the flashlight reflector screen (trough some translucent filters), like Skywatcher does - it eliminates the external influences better.

Search for "luxmeter" in the stores of your phone OS for a suitable application. There are plenty of them.