Searching \ for '[EE] Wind up Torch' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=wind+torch
Search entire site for: 'Wind up Torch'.

Exact match. Not showing close matches.
PICList Thread
'[EE] Wind up Torch'
2012\02\29@095030 by alan.b.pearce

face picon face
I have an LED torch that gets its power from being wound up. It has died, and now won't charge up by winding, well winding produces voltage, but it won't retain charge. Had a look inside it, the generator produces about 12V when wound, but the capacitor looking piece immediately drops back to about 3V when you stop winding.

Does anyone know what is used for energy storage in these? The device in it looks like a capacitor, marked
3.6V 80mAh
12hr 8ma

>From the way the voltage across it drops back to almost nothing I'm guessing it has gone AWOL.



-- Scanned by iCritical.

2012\02\29@101646 by Isaac Marino Bavaresco

flavicon
face
Em 29/2/2012 11:50, spam_OUTalan.b.pearceTakeThisOuTspamstfc.ac.uk escreveu:
> I have an LED torch that gets its power from being wound up. It has died, and now won't charge up by winding, well winding produces voltage, but it won't retain charge. Had a look inside it, the generator produces about 12V when wound, but the capacitor looking piece immediately drops back to about 3V when you stop winding.
>
> Does anyone know what is used for energy storage in these? The device in it looks like a capacitor, marked
>
> 3.6V 80mAh
> 12hr 8ma
>
> >From the way the voltage across it drops back to almost nothing I'm guessing it has gone AWOL.


The "mAh" rating is used for batteries.

Perhaps a LiFePo4 battery (lithium-iron-phosphate). They are rated at
3.3V per cell, the open circuit voltage is about 3.2V and the max.
charging voltage is 3.6V.
Or a LiPo (lithium-polymer). They are rated at 3.7V per cell with a max.
charging voltage of 4.2V


Best regards,

Isaac

2012\02\29@103647 by John Gardner

picon face
3.6 V might also be the voltage associated with 3 NiCd cells in
series - I'm thinking of what's inside a "9V" NiCd..

2012\02\29@104104 by Walter Banks

flavicon
face
I had a similar device fail a couple months ago. I was expecting a high energy cap or a
rechargable battery and was very surprised that the "storage" component was a 2032
coin cell. I replaced it with a 2032 CMOS backup battery from an junked PC.

w..

.....alan.b.pearceKILLspamspam@spam@stfc.ac.uk wrote:

{Quote hidden}

>

2012\02\29@110555 by John Gardner
picon face
I remember seeing rechargeable lithium coin cells in Digikey
or Mouser..

2012\02\29@110635 by alan.b.pearce

face picon face
> I had a similar device fail a couple months ago. I was expecting a high energy cap
> or a rechargable battery and was very surprised that the "storage" component was a
> 2032 coin cell. I replaced it with a 2032 CMOS backup battery from an junked PC.
>
> w..

This looks more like a battery, but under the shrink wrap the case looks more like that of a cap, rather than some cells in series, which would be needed for a NiCd battery. It may be a single cell Li-something, hence the ratings on it.

I may attempt to organise a piccy ...



-- Scanned by iCritical.

2012\02\29@110759 by Paul Hutchinson

picon face
> -----Original Message-----
> From: piclist-bouncesspamKILLspammit.edu On Behalf Of Isaac Marino Bavaresco
> Sent: Wednesday, February 29, 2012 10:17 AM
>
>
> Em 29/2/2012 11:50, .....alan.b.pearceKILLspamspam.....stfc.ac.uk escreveu:
> > I have an LED torch that gets its power from being wound up.
<snip>
> the generator produces about 12V when wound, but the
> capacitor looking piece immediately drops back to about 3V when
> you stop winding.
> >
> > Does anyone know what is used for energy storage in these? The
> device in it looks like a capacitor, marked
> >
> > 3.6V 80mAh
<snip>
>
> The "mAh" rating is used for batteries.
>
> Perhaps a LiFePo4 battery (lithium-iron-phosphate). They are rated at
<snip>
>
> Best regards,
> Isaac

It could be a Ni-MH 3.6V 80 mAh memory backup battery pack. Made by a few
different manufacturers, Dantona COMP-16-1NMH, Gold Peak GP60BNK3A1H, Varta
3/V60R, 3/60DK, 3/V80H-2P.

If it is this battery then AFAIK, charging directly from a 12V generator
would not be good for a long life.

Paul Hutch

2012\02\29@111215 by V G

picon face
I would totally expect a super capacitor or something for this sort of
thing. What are the effects of loading 12V across a single Li-ion cell? Or
am I missing something about Ohm's law and that 12V will actually drop to a
much lower voltage due to the near 0-Ohm ESR of the battery and the
effective charging input power to the battery is within a safe range

2012\02\29@111302 by John Gardner

picon face
www.mouser.com/Power/Batteries/Coin-Cell-Battery/_/N-965wk?P=1z0y70e&Keyword=batteries&FS=Tru

2012\02\29@115205 by alan.b.pearce

face picon face
> http://www.mouser.com/Power/Batteries/Coin-Cell-Battery/_/N-965wk?P=1z0y70e&Keyword=batteries&FS=True

Doesn't produce any products for me. Were you logged in?


-- Scanned by iCritical.

2012\02\29@121107 by alan.b.pearce

face picon face
> It could be a Ni-MH 3.6V 80 mAh memory backup battery pack. Made by a few different
> manufacturers, Dantona COMP-16-1NMH, Gold Peak GP60BNK3A1H, Varta 3/V60R, 3/60DK,
> 3/V80H-2P.
>
> If it is this battery then AFAIK, charging directly from a 12V generator would not
> be good for a long life.
>
> Paul Hutch

I am rapidly deciding that is what it is.
I suspect the generator is highly current limited, so with a properly functioning battery the charge current would be fine. Remember it is 'just' a magnet spinning inside some coils, and I suspect the air gap isn't that small.. Might take the battery out, put in a 3.6V zener and see what sort of current I can get when cranking the handle.

Hmm, Farnell item 200-9025 might be a viable replacement battery when fitted in a holder. Could be persuaded to fit in the available space OK, and even with holder, would be cheaper than a replacement torch.


-- Scanned by iCritical.

2012\02\29@121223 by John Gardner

picon face
That's interesting - Apparently they filter what they show to who...

Try  Mouser.com, Products » Power » Batteries » Coin Cell Battery,
click on "Rechargeable"

Does this come up?

http://www.mouser.com/ProductDetail/Panasonic-Battery/VL2330-1VC/?qs=sGAEpiMZZMtEV04R3uo8FhJmTHwxci9IT7IH3kCT6SU%3d

2012\02\29@122821 by alan.b.pearce

face picon face
> That's interesting - Apparently they filter what they show to who...

Could do, especially when in different countries. They may not like the possibility of shipping small quantities of potentially dangerous items internationally.

>
> Try  Mouser.com, Products > Power > Batteries > Coin Cell Battery, click on
> "Rechargeable"
>
> Does this come up?
>
> www.mouser.com/ProductDetail/Panasonic-Battery/VL2330-
> 1VC/?qs=sGAEpiMZZMtEV04R3uo8FhJmTHwxci9IT7IH3kCT6SU%3d
>
This link does show a coin cell battery as an item.


-- Scanned by iCritical.

2012\02\29@132414 by Barry Gershenfeld

picon face
I have a flashlight with coin cells in it.  It is a counterfeit!  I figured
this out ahead of time, so the flashlight is temporarily serving time as a
"disposable".  The "magnet" was a chunk of iron, and the coil wasn't even
connected

2012\02\29@141558 by Walter Banks

flavicon
face


Paul Hutchinson wrote:

{Quote hidden}

I didn't think that charging a Li cell was a good idea. The wind up flashlight
I have last a few months of almost no use before the battery failed. The
generator would light the LED's but no charge was stored replacing the
coin cell worked I expect for an equally short period of time

w..

2012\02\29@164058 by IVP

face picon face

> If it is this battery then AFAIK, charging directly from a 12V generator
> would not be good for a long life.

Many fakes are being produced, of both wind-up and Faraday (shaken)
torches. Have read about the wind-ups, can't remember the details, but
the 'magnet' in some Faraday torches is actually a lump of iron and the
'storage capacitor' is a battery. So you think you're charging a big cap,
but in fact the LED is running off a (probably not very good) battery and
a small mediocre cap. I know, I got suckere

2012\02\29@183244 by RussellMc

face picon face
> I have an LED torch that gets its power from being wound up. It has died,
> and now won't charge up by winding, well winding produces voltage, but it
> won't retain charge. Had a look inside it, the generator produces about
12V
> when wound, but the capacitor looking piece immediately drops back to
about
> 3V when you stop winding.

Original battery is most likely a NiCd with 3 cells but, as Joe says, many
fakes exist.
A supercap could be used BUT chargeup time is significant until LED can
light.
eg if a supercap was rated at 4V max and LED lit OK at 3V or above, then
due to E = 0.5CV^2 you need to charge cap to 3^2/4^2 =~ 55% of its capacity
before LED lights OK.

12 Voc is OK as current is what counts and battery will clamp alternator to
form a constant current source. EXCEPT if battery charges to full capacity
(unlikely) when voltage will cause problems.

Some lights are outright non-workers with primary cells being used to
simulate crank or shaker action. Others may "try" to charge primary cells -
which may work to some extent in some cases.

Some shakers do work but do not have the energy output levels to operate an
LED well or to charge their battery well.

Most crank lights are liable to be genuine but may be arranged to run on
either LEDs or primary cells without charging.
Crank is electrically not too hard to do so more are liable to be genuine
than shakers. Crank lights tend to be mechanically far less efficient than
is desirable. About 1 Watt out continuous is achievable with the multistage
plastic gear trains often used. Properly done hand power can produce 5 to
10 Watts with less effort than from a 1 W crank or squeeze light.


   Russel

2012\02\29@232638 by John Gardner

picon face
Remember that the generator has a "Series ESR" too..

2012\02\29@233441 by Bob Blick

face
flavicon
face
My Harbor Freight windup keychain light has a lithium-ion battery that
sound a lot like that.

http://www.harborfreight.com/mini-dynamo-keychain-flashlight-99859.html

Cheers,

Bob


On Wed, Feb 29, 2012, at 02:50 PM, alan.b.pearcespamspam_OUTstfc.ac.uk wrote:
{Quote hidden}

> -


'[EE] Wind up Torch'
2012\03\01@123154 by Joe Wronski
flavicon
face
I have one labelled "Garrity".  It works, some, and I just disassembled it and it has a battery marked:
SORBO
NI-MH Cell
3.6V 80 mAh
14hrs at 8 mA

If you're seeing 12V winding it, with everything still connected, then the battery has failed open.
Joe W


On 2/29/2012 9:50 AM, @spam@alan.b.pearceKILLspamspamstfc.ac.uk wrote:
> I have an LED torch that gets its power from being wound up. It has died, and now won't charge up by winding, well winding produces voltage, but it won't retain charge. Had a look inside it, the generator produces about 12V when wound, but the capacitor looking piece immediately drops back to about 3V when you stop winding.
>
> Does anyone know what is used for energy storage in these? The device in it looks like a capacitor, marked
>
> 3.6V 80mAh
> 12hr 8ma
>
>> From the way the voltage across it drops back to almost nothing I'm guessing it has gone AWOL.
>
>
>

2012\03\02@040359 by alan.b.pearce

face picon face
> I have one labelled "Garrity".  It works, some, and I just disassembled it and it
> has a battery marked:
> SORBO
> NI-MH Cell
> 3.6V 80 mAh
> 14hrs at 8 mA

That is the same brand as in mine.

>
> If you're seeing 12V winding it, with everything still connected, then the battery
> has failed open.
> Joe W

That is my belief as well.

I have occasion to order some parts today, so I will add the rechargeable 2450 coin cell and holder to the order, and see how we get on.


-- Scanned by iCritical.

2012\03\02@110332 by RussellMc

face picon face
> I would totally expect a super capacitor or something for this sort of
> thing. What are the effects of loading 12V across a single Li-ion cell? Or
> am I missing something about Ohm's law and that 12V will actually drop to
> a much lower voltage due to the near 0-Ohm ESR of the battery and the
> effective charging input power to the battery is within a safe range?

the alternator current limits when a low impedance load is applied and
acts like a constant current source at about the battery voltage. IF
you apply it to a Lithium Ion cell (or most other chemistry types)
that is fully charged then it will potentially do damage, but until
then it works acceptably.

The alternator is rated at Valt >> Vbat at full revs so that it can
still charge at less than full revs.


             Russel

More... (looser matching)
- Last day of these posts
- In 2012 , 2013 only
- Today
- New search...