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Re: Can a small photocell panel be connected to a flashlight type rechargable battery?

Newsgroups	sci.electronics.design
Subject	Re: Can a small photocell panel be connected to a flashlight type rechargable battery?
References	<fhntrd1aq3c9jkfp3haigrk512mdfc5aj8@4ax.com>
From	dplatt@coop.radagast.org (Dave Platt)
Message-ID	<dfe49f-cuq.ln1@coop.radagast.org> (permalink)
Date	2018-10-11 10:39 -0700

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In article <fhntrd1aq3c9jkfp3haigrk512mdfc5aj8@4ax.com>,
 <oldschool@tubes.com> wrote:
>I acquired a dead solar cellphone charger unit. I did minimal testing of
>it, and it was totally dead. It has the surface mount components, so I
>did not go any further. I salvaged the 2.5" X 4" solar cell panel, and
>tossed the rest of it. In a lighted room, (lights turned on) it puts out
>just under one volt DC. I imagine it will put out more voltage in
>sunlight, but I have not tried it, since we have not seen the sun in
>days.

If it's showing 1 volt "open circuit" in room light, when measured
with a high-impedance voltmeter, then I think it's unlikely to put out
much more voltage under direct sunlight.  More current, yes;  more
voltage, no.

>Anyhow, can I connect that panel directly to a common AA rechargable
>battery? (or maybe I should charge two batrteries at once, in series)?

You _can_ connect it directly to one or two batteries in series.

It is unlikely to charge them at all, based on what you've written.

>If not, is there a simple circuit I can build, or should I just steal a
>circuit board from one of them solar yard lights, (which have a much
>smaller solar panel).

Ideally, what you would have is a voltage-boost circuit which is
capable of raising the voltage enough to charge the batteries, _and_
to do so in a way which operates the panel at its point of maximum
power delivery.  Professional solar charge-control circuits do this
(although they usually _drop_ a higher panel voltage via a buck
regulator).

You might want to look into the simple "joule thief" circuit.  This is
a simple blocking oscillator voltage booster, which is often used in
small LED flashlights to boost a single AA cell (1.5 volts nominal) to
a high enough voltage to turn on a white LED (roughly 5 volts I
believe).  You might be able to build one which can boost a 1-volt
panel's output up above 1.4 volts (enough to charge a NiCd or NiMH).

Thread

Can a small photocell panel be connected to a flashlight type rechargable battery? oldschool@tubes.com - 2018-10-11 00:32 -0500
  Re: Can a small photocell panel be connected to a flashlight type rechargable battery? <698839253X6D445TD@nospam.org> - 2018-10-11 06:10 +0000
  Re: Can a small photocell panel be connected to a flashlight type rechargable battery? tabbypurr@gmail.com - 2018-10-11 05:51 -0700
  Re: Can a small photocell panel be connected to a flashlight type rechargable battery? George Herold <gherold@teachspin.com> - 2018-10-11 06:18 -0700
  Re: Can a small photocell panel be connected to a flashlight type rechargable battery? dplatt@coop.radagast.org (Dave Platt) - 2018-10-11 10:39 -0700
    Re: Can a small photocell panel be connected to a flashlight type rechargable battery? bitrex <user@example.net> - 2018-10-11 22:41 -0400
  Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-11 12:14 -0700
    Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jasen Betts <jasen@xnet.co.nz> - 2018-10-11 22:34 +0000
      Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-11 19:31 -0700
        Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jasen Betts <jasen@xnet.co.nz> - 2018-10-12 05:02 +0000
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-11 23:05 -0700
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 09:08 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 09:36 -0700
              Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 10:20 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 10:37 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 09:41 -0700
              Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 10:04 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jasen Betts <jasen@xnet.co.nz> - 2018-10-12 19:24 +0000
              Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 18:26 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 22:27 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jasen Betts <jasen@xnet.co.nz> - 2018-10-13 05:32 +0000
        Re: Can a small photocell panel be connected to a flashlight type rechargable battery? John S <Sophi.2@invalid.org> - 2018-10-12 02:12 -0500
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 09:15 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? John S <Sophi.2@invalid.org> - 2018-10-13 15:14 -0500
              Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-14 20:34 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? John S <Sophi.2@invalid.org> - 2018-10-15 20:39 -0500
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-15 21:28 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? John S <Sophi.2@invalid.org> - 2018-10-16 18:08 -0500
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-16 16:29 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-16 16:47 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? John S <Sophi.2@invalid.org> - 2018-10-17 02:23 -0500
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 09:23 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 09:48 -0700
              Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 17:57 -0700
                Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 22:19 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jasen Betts <jasen@xnet.co.nz> - 2018-10-12 19:56 +0000
        Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2018-10-12 07:36 +0000
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? George Herold <gherold@teachspin.com> - 2018-10-12 05:59 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2018-10-12 13:06 +0000
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-12 09:18 -0700
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? Jeff Liebermann <jeffl@cruzio.com> - 2018-10-12 09:44 -0700
            Re: Can a small photocell panel be connected to a flashlight type rechargable battery? <698839253X6D445TD@nospam.org> - 2018-10-12 17:57 +0000
        Re: Can a small photocell panel be connected to a flashlight type rechargable battery? whit3rd <whit3rd@gmail.com> - 2018-10-12 23:23 -0700
          Re: Can a small photocell panel be connected to a flashlight type rechargable battery? gnuarm.deletethisbit@gmail.com - 2018-10-13 04:56 -0700

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