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'[EE] Battery suggestions?'
2006\01\30@031808
by
Chris Emerson
|
I'm looking for a battery for a (hobby) project, and I'd be interested
in any suggestions.
Requirements (most are flexible):
* Needs to be quite small; the usual AA/AAA are a bit bigger than I'd
like. Something about the size of a CR2032 would be great, but could be
a bit bigger.
* Current needs are 5-10mA continuously (a small PIC and other bits),
with regular short bursts of about 30-50mA (driving a 40kHz ultrasonic
transducer). The battery would ideally last at least half an hour.
* This project may occasionally be dropped, possibly from ~10 feet.
It's not a disaster if a removable battery comes out at impact, but I'd
hope it wouldn't be too damaged.
* Preferably rechargeable, so I don't have to keep buying more
batteries. I'd be willing to build a simple charger (eg with an
easy-to-use IC) for it.
* Unless it's 5-6V (regulated down for the PIC), I'll need to work out
how to boost it to drive the tansducer with ~10V peak-to-peak.
Now that I write it down it sounds pretty difficult to achieve! I'd
appreciate any suggestions.
Regards,
Chris
2006\01\30@034628
by
Bob Axtell
A LiIon might be located (3.6V) that could be boosted to 5V regulated.
There MIGHT be a paper-thin NiMH, but I doubt it.
A CR2032 can't even deliver 10mA.
A 10' drop is a very heavy drop! Not many products will survive that, except
the older Fluke meters.
Chris Emerson wrote:
{Quote hidden}>I'm looking for a battery for a (hobby) project, and I'd be interested
>in any suggestions.
>
>Requirements (most are flexible):
>* Needs to be quite small; the usual AA/AAA are a bit bigger than I'd
>like. Something about the size of a CR2032 would be great, but could be
>a bit bigger.
>
>* Current needs are 5-10mA continuously (a small PIC and other bits),
>with regular short bursts of about 30-50mA (driving a 40kHz ultrasonic
>transducer). The battery would ideally last at least half an hour.
>
>* This project may occasionally be dropped, possibly from ~10 feet.
>It's not a disaster if a removable battery comes out at impact, but I'd
>hope it wouldn't be too damaged.
>
>* Preferably rechargeable, so I don't have to keep buying more
>batteries. I'd be willing to build a simple charger (eg with an
>easy-to-use IC) for it.
>
>* Unless it's 5-6V (regulated down for the PIC), I'll need to work out
>how to boost it to drive the tansducer with ~10V peak-to-peak.
>
>Now that I write it down it sounds pretty difficult to achieve! I'd
>appreciate any suggestions.
>
>Regards,
>
>Chris
>
>
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2006\01\30@041411
by
Jinx
> * Needs to be quite small; the usual AA/AAA are a bit bigger
> than I'd like. Something about the size of a CR2032 would be
> great, but could be a bit bigger
How about a couple of AAAA alkaline ? 3.65V, 625mAh, can
be boosted to the PIC's Vdd (do you really need 5V for that ?)
and 10V-ish with a simple oscillator
2006\01\30@060118
by
Jinx
> How about a couple of AAAA alkaline ? 3.65V
Sorry, typo. 1.65V (each, when new)
2006\01\30@082615
by
Chris Emerson
On Mon, Jan 30, 2006 at 10:13:31PM +1300, Jinx wrote:
> > * Needs to be quite small; the usual AA/AAA are a bit bigger
> > than I'd like. Something about the size of a CR2032 would be
> > great, but could be a bit bigger
>
> How about a couple of AAAA alkaline ? 3.65V, 625mAh,
Ooh, I hadn't heard of AAAAs. They look like thinner AAAs, though, and
it's the length that's the problem (which I hadn't specified earlier).
It wants to fit into the smallest sphere possible, IYSWIM.
You've reminded me of N batteries though, which I think are roughly
half-length AA.
> can be boosted to the PIC's Vdd (do you really need 5V for that ?) and
> 10V-ish with a simple oscillator
No, I don't need 5V for the PIC, as long as it can still drive the
transducer at a higher voltage.
Thanks,
Chris
2006\01\30@085543
by
Chris Emerson
On Mon, Jan 30, 2006 at 01:46:26AM -0700, Bob Axtell wrote:
> A LiIon might be located (3.6V) that could be boosted to 5V regulated.
Hmm, a quick look through Farnell didn't show any below 20 UKP (~$30).
> There MIGHT be a paper-thin NiMH, but I doubt it.
It doesn't have to be paper thin (sorry for unclear specs). A
half-inch-thick button-cell would be just fine, I mostly worried about
the size of a sphere the whole device could fit into.
> A 10' drop is a very heavy drop! Not many products will survive that,
> except the older Fluke meters.
Hopefully a combination of padding, potting compound, and being careful
will do.
Thanks,
Chris
2006\01\30@105936
by
Mark Jeronimus
On 1/30/06, Chris Emerson <.....picKILLspam
@spam@nosreme.org> wrote:
> You've reminded me of N batteries though, which I think are roughly
> half-length AA.
If N batteries are what I think they are, then they are 12V cells which can
deliver at most 10 mA. I have similar batteries at home inside professional
active microphones. I once opened up an empty battery, and it contained 6
button cells with unusual dimensions.
Mark
2006\01\30@110823
by
Chris Emerson
On Mon, Jan 30, 2006 at 04:59:35PM +0100, Mark Jeronimus wrote:
> On 1/30/06, Chris Emerson <pic
KILLspamnosreme.org> wrote:
> > You've reminded me of N batteries though, which I think are roughly
> > half-length AA.
>
> If N batteries are what I think they are, then they are 12V cells which can
> deliver at most 10 mA. I have similar batteries at home inside professional
> active microphones. I once opened up an empty battery, and it contained 6
> button cells with unusual dimensions.
No, N batteries are 1.5V alkalines. I know the 12V ones you mean, often
used in security keyfobs.
Regards,
Chris
2006\01\30@112215
by
D. Jay Newman
2006\01\30@114006
by
William Chops Westfield
On Jan 30, 2006, at 5:26 AM, Chris Emerson wrote:
> * Needs to be quite small; the usual AA/AAA are a bit bigger
> than I'd like. Something about the size of a CR2032 would be
> great, but could be a bit bigger
There are lithium polymer cells in that size range that deliver
~100 mAH and up to several hundred mA. Expensive, but they
sound spot-on to your requirements. Subject to requirements for
careful charging if you don't want them to burst into flames...
Representative listing:
http://www.bsdmicrorc.com/products.cfm?catID=10001
BillW
2006\01\30@120141
by
William Chops Westfield
2006\01\30@121932
by
David VanHorn
I just worked with a fun li-po cell, roughly the size of a buisness card,
and 10 mils thick.
200mAh, and would withstand 200 mA drain without loosing too much capacity.
Pretty soon, the battery will be the wing covering!
2006\01\30@131215
by
Peter Todd
On Mon, Jan 30, 2006 at 12:19:32PM -0500, David VanHorn wrote:
> I just worked with a fun li-po cell, roughly the size of a buisness card,
> and 10 mils thick.
> 200mAh, and would withstand 200 mA drain without loosing too much capacity.
>
> Pretty soon, the battery will be the wing covering!
Is it safe to say that ultra-thin and flat cells like that one are able
to provide higher currents relative to their size in general? I'm
assuming that they would make for higher surface areas of the reactants,
but that's just my intuition.
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2006\01\30@142045
by
Larry G. Nelson Sr.
N cells are short AA type cells at 1.5V. I use them in my HP41CV calculator.
Larry
---- Mark Jeronimus <zombie.piclist
spam_OUTgmail.com> wrote:
> On 1/30/06, Chris Emerson <@spam@picKILLspam
nosreme.org> wrote:
> > You've reminded me of N batteries though, which I think are roughly
> > half-length AA.
>
> If N batteries are what I think they are, then they are 12V cells which can
> deliver at most 10 mA. I have similar batteries at home inside professional
> active microphones. I once opened up an empty battery, and it contained 6
> button cells with unusual dimensions.
>
> Mark
> --
2006\01\30@142858
by
Mark Rages
On 1/30/06, Chris Emerson <KILLspampicKILLspam
nosreme.org> wrote:
> * Unless it's 5-6V (regulated down for the PIC), I'll need to work out
> how to boost it to drive the tansducer with ~10V peak-to-peak.
Can you bridge the transducer across two outputs and drive them
out-of-phase? That will double the voltage the transducer sees.
Regards,
Mark
markrages@gmail
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2006\01\30@142959
by
David VanHorn
>
> Is it safe to say that ultra-thin and flat cells like that one are able
> to provide higher currents relative to their size in general? I'm
> assuming that they would make for higher surface areas of the reactants,
> but that's just my intuition.
Pulse current yes. This one used some special electrode treatments to get
more power than normal. In the end, for total watt-hours, it all comes down
to what reactants you're using, and their mass.
2006\01\30@151226
by
William Chops Westfield
On Jan 30, 2006, at 10:26 AM, Peter Todd wrote:
> Is it safe to say that ultra-thin and flat cells like that one
> are able to provide higher currents relative to their size in
> general?
I don't think so. In the Li-ion realm, I think even the cylinder
cells are essentially wound up spools of thin ribbon-like electrodes.
(that probably explains why Li-ion cells have such impressive
current delivery capability, especially if you don't care about
wrecking them.) (says so explicitly here:
<http://www.panasonic.com/industrial/battery/oem/images/pdf/
Panasonic_LiIon_Overview.pdf>)
BillW
2006\01\30@163237
by
Jinx
> You've reminded me of N batteries though, which I think are
> roughly half-length AA
How about two of these ?
http://www.rsnewzealand.com
Product code 2636033
NiMH, 12mm long x 17mm diameter, 2.4V, 80mAh
If this is a one-off, perhaps take something apart and use the
bits - like a cell-phone battery pack ?
2006\01\30@181732
by
Chris Emerson
On Tue, Jan 31, 2006 at 10:33:09AM +1300, Jinx wrote:
> > You've reminded me of N batteries though, which I think are
> > roughly half-length AA
>
> How about two of these ?
>
> http://www.rsnewzealand.com
>
> Product code 2636033
>
> NiMH, 12mm long x 17mm diameter, 2.4V, 80mAh
Ooh, they look like just the ticket, and quite reasonably priced.
Thanks!
Chris
2006\01\31@150927
by
Howard Winter
On Mon, 30 Jan 2006 16:08:23 +0000, Chris Emerson wrote:
>...
> I know the 12V ones you mean, often
> used in security keyfobs.
Called A23, I believe.
Cheers,
Howard
'[EE] Battery suggestions?'
2006\02\02@083138
by
Alan B. Pearce
>> There MIGHT be a paper-thin NiMH, but I doubt it.
>
>It doesn't have to be paper thin (sorry for unclear specs).
>A half-inch-thick button-cell would be just fine, I
>mostly worried about the size of a sphere the whole
>device could fit into.
A replacement rechargeable battery for a PC Bios? There were a few that used
small nicad cells, and IIRC some were two or 3 cell button types.
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