Betavoltaic (Beta-Photo-Voltaic)

[julius oe.]

Here is a story:

Everybody has a bunch of empty batteries ling around....

What if they charge them self in the time you don't use them.


The idea:

Take a Tritium (12+ years) glowing stick:



a small solar panel and a super cap.

... that is what I tried. I only took a 22µF Cap and used a calculator solar panel. I packed everything together in a box. After a about 60mins the voltage climbed to 150mV. I got a new super cap with 0,47F and i got me some new solar panels, but those don't work at all.

To make this in a AA batteries size product, i see following possibilities. The low voltage (solar) output can be collected but it must be boosted to, lets say, 1,8V into a super cap. to talk about efficiency: a round, to the inside looking, solar panel would take almost photon of the source. The Tritium glow stick could be more active, or it could be bigger. The radiation is Beta(minus) so we 'only' have fast electrons, witch can be shielded easily ..there is a lot more.. but i think its possible.

The recharge time would take weeks or months.. but that's what I'm calling regenerative ! (;

were can we use it?

TV-IR-Transmitter, recharging LED-Flashlight.... ??

(holding the solar panel a few second into sun-light would charge the cap in seconds .. i know)

[julius oe.]

I'm just saying, the idea is great - it's not mine!

what someone already have done:
https://youtu.be/LUNDobqczW4

[Alex Eisenhut]

[dmwahl]

The energy stored in a capacitor is 1/2*C*V^2, so for your 22uF cap at 150mV that's about 0.25 micro joules. Assuming a fully charged NiMH AA cell contains about 3Wh of energy (2.5Ah x 1.2V), that's 10,800 joules. At 0.25 micro joules per hour, it would take about 5 million years to charge the battery if you ignored self discharge.