Comments on: Solar batteries

By: Brian "Hack" Jameson

Brian "Hack" Jameson — Thu, 12 Aug 2010 02:11:23 +0000

Beautiful to look at, but the inefficiency would annoy me – it’s impossible to have all of the panel facing the sun at the same time. The good news is that flexible solar panels are on the way, and people will find all sorts of places to affix them.

By: Ambigrid System

Ambigrid System — Sat, 19 Sep 2009 06:32:57 +0000

I used the Ambigrid Plans to build a solar pales for under $100, as well as a solar water heater for less than $10! I can’t say enough good things about them!

By: nicsky

nicsky — Thu, 19 Mar 2009 14:39:09 +0000

as far as i know, a solar cell will discharge a battery if it is not in the light.
A diode is requuired to stop discharge

By: MDude

MDude — Sun, 08 Mar 2009 05:55:37 +0000

I wonder if it would be possible (or rather, practicle) to fit a bridge rectifier into a battery case and use it to get power from radio vaves like this: http://www.instructables.com/id/Radio-Voltage-Steal/

As long as the rectifier isn’t put in an electromagneticly sheilded container, it should be able to harvest power, and I’m thinking most portable devices arn’t concerned with sheilding their batteries. From what I’ve read, I think there are some voltage and current regulation issues to deal with, but it might be something for me to work on over the summer once I get the hang of soldering.

By: steve

steve — Sat, 21 Feb 2009 04:35:19 +0000

great idea but why not just stick a solar panel on one side and have a cheep plastic tray so you can stick them by a window?

By: mem

mem — Sat, 21 Feb 2009 02:38:43 +0000

nitori,
Not to nitpick but you are an absolute dickhead. That question has been covered no less than 10 times.

By: Nitori

Nitori — Fri, 20 Feb 2009 14:07:11 +0000

Not to nitpick but shouldn’t there be a blocking diode in series with the solar cell so the batteries don’t discharge in the dark?

By: mem

mem — Fri, 20 Feb 2009 00:10:07 +0000

Thankyou nick for paraphrasing what has allready said 20 times previously. Why bother to paste your comment if your not going to read the rest.

Hoping that someone will read this far and think “Well, that Nick is really insightfull – the other 50 posters didnt quite sum it up”. Trust me, it doesnt happen.

By: nick

nick — Thu, 19 Feb 2009 08:35:41 +0000

Good idea, if only solar cells weren’t expensive as hell and so poor in performance. The already weak solar cell would get only a small part of direct sunlight which makes them nearly useless. Furthermore, the cells that don’t get sunlight will behave as polarized resistors, wasting even more power.
A flat cell array is still the best solution, both in performance and price.

By: strider_mt2k

strider_mt2k — Wed, 18 Feb 2009 15:21:22 +0000

good thing you’re here to add fiber to the content, mem.

I think i feel a bowel movement coming on.

By: mem

mem — Wed, 18 Feb 2009 09:11:00 +0000

Everything that needs to be said, was said between the 1st post and dejagerd’s,

Points at the rest of you morons and rolls eyes.

By: james

james — Wed, 18 Feb 2009 04:44:26 +0000

The perfect next step would be a unified charge controller/output voltage regulator, to get a stable output voltage as the battery discharges.

By: Josh

Josh — Wed, 18 Feb 2009 03:56:29 +0000

Most of you are putting this project down because it has a couple of problems (cost, etc). There’s a reason it’s called a *prototype*! Cost? When rechargables and solar cells first came out, they were quite costly. Now, you can find a solar-powered calculator for $1. The flexible cells are a relatively new concept. Given time, this project can be a very viable solution for some applications.

By: colecoman1982

colecoman1982 — Tue, 17 Feb 2009 18:40:45 +0000

Consolidated list of problems with this concept:

* A very small percentage of the solar cells facing the sun at any time.

* Cost

* Even the best rechargable batteries will die long before the solar cell making the cell a waste as it’s glued to a dead cell now.

* Some rechargable batteries, lithium ion in particular, have their total cycle life dependent on the temperature they are stored at. By leaving them in direct sunlight you, probably, shorten their life dramatically.

* Many types of rechargable batteries, litium ion in particular, require advanced recharging circuits in order to charge without causing damage to the cell. There isn’t any space to put that circuitry and still have the batteries fit in a standard battery slot.

By: fartface

fartface — Tue, 17 Feb 2009 16:51:20 +0000

Gimmick.

Less than 8.9% of the solar cell surface is in direct incident with the light. This is simply a “neato” thing and not useful at all. All those flexible cells on a flat plane and pointed at the light source would be at least 600% more efficient.