Battery Power for Raspberry Pi

[jywarren]

indeed! def. need to think about this. I know you have some ideas :-)

On Thu, Jan 31, 2013 at 6:01 PM, dwblair notifications@github.com wrote:

— Reply to this email directly or view it on GitHubhttps://github.com/jywarren/irkit/issues/7.

[atrawog]

What would be great is a proper step-down DC to DC converter for the Raspberry that can handle 6-14V input from a solar battery. Most 12V to 5V USB converter are horrible inefficient and have a tendency to fry your USB measuring equipment.

[dwblair]

Andreas -- good call, absolutely! For this purpose, I was looking at the following part:

http://www.ti.com/lit/ds/symlink/lm2576.pdf

I think it might do the trick?

On Fri, Feb 1, 2013 at 7:55 AM, Andreas Trawoeger notifications@github.comwrote:

What would be great is a proper step-down DC to DC converter for the Raspberry that can handle 6-14V input from a solar battery. Most 12V to 5V USB converter are horrible inefficient and have a tendency to fry your USB measuring equipment.

— Reply to this email directly or view it on GitHubhttps://github.com/jywarren/irkit/issues/7#issuecomment-12992907.

voice / SMS: +1-651-252-4765 skype: dwingateb

[dwblair]

Oh wait -- I don't think that part quite covers the relevant input range. Searching ...

On Fri, Feb 1, 2013 at 9:27 AM, Don Blair donblair@gmail.com wrote:

Andreas -- good call, absolutely! I was looking at this part for this very purpose:

http://www.ti.com/lit/ds/symlink/lm2576.pdf

I think it might do the trick?

On Fri, Feb 1, 2013 at 7:55 AM, Andreas Trawoeger < notifications@github.com> wrote:

What would be great is a proper step-down DC to DC converter for the Raspberry that can handle 6-14V input from a solar battery. Most 12V to 5V USB converter are horrible inefficient and have a tendency to fry your USB measuring equipment.

— Reply to this email directly or view it on GitHubhttps://github.com/jywarren/irkit/issues/7#issuecomment-12992907.

voice / SMS: +1-651-252-4765 skype: dwingateb

voice / SMS: +1-651-252-4765 skype: dwingateb

[dwblair]

So, the part I mentioned above: http://www.ti.com/lit/ds/symlink/lm2576.pdf seems to allow for a minimum input voltage of 7V; it can output up to 3A.

I was thinking that it'd be neat to have the ability to use e.g. a rechargeable LiPo battery of around 3.7 V, like the ones that are sold on Adafruit: http://www.adafruit.com/products/328

For handing lower voltage inputs like that, and for still being able to output up to 1.5 A (I think this will be enough for the R-Pi + peripherals?), I found these parts: http://www.onsemi.com/pub_link/Collateral/MC34063A-D.PDF http://www.onsemi.com/pub_link/Collateral/NCP3063-D.PDF

The latter part seems to be an upgrade of the widely-used former part. Will look online to see if anyone has any comments about using either of these parts with the R-Pi (if they're appropriate at all for this purpose!) ...

[dwblair]

This discussion: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=40&t=33498

Led me to this product: http://www.hobbyking.com/hobbyking/store/__15212__HobbyKing_Micro_UBEC_3A_5v.html

Not yet sure whether it's appropriate for powering a Pi ...