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I was wondering if anyone here has any concrete experience with how long you can expect a (decent quality) CR2032 to work connected to RTXC/VBAT on something like a 2148? I was using RTC to wake the device up regularly, send some data, and then drop back into low power mode, but I don't really know how long I should expect the battery to survive ... obviously one day or another the device just isn't going to 'wake up' anymore. I would assume something like 1-2 years should be OK?

------------------------------------



(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )

One year if the battery is sourcing all time. 200mA (CR2032) and 20uA internal RTC.

leomecma
----- Original Message -----
From: kevin_townsend2
To: l...@yahoogroups.com
Sent: Friday, November 06, 2009 9:56 PM
Subject: [lpc2000] Life Expectancy of CR2032 Battery w/RTC

I was wondering if anyone here has any concrete experience with how long you can expect a (decent quality) CR2032 to work connected to RTXC/VBAT on something like a 2148? I was using RTC to wake the device up regularly, send some data, and then drop back into low power mode, but I don't really know how long I should expect the battery to survive ... obviously one day or another the device just isn't going to 'wake up' anymore. I would assume something like 1-2 years should be OK?

[Non-text portions of this message have been removed]

------------------------------------



(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )

--- In l...@yahoogroups.com, "Leo" wrote:
>
> One year if the battery is sourcing all time. 200mA (CR2032) and 20uA internal RTC.
>
> leomecma
>

I measure the operating current into a LPC2366 part as 18 microAmps. (0.0000178 A) (0.178V/10K) The CR2032 battery is 230 mA-hour capacity so that should work out to be (theoretically) about 12,900 hours... Or, 1 and 1/2 years ! (17 months)

I haven't seen mine last for more than a few months on an LPC2103, but I never did measure the current draw on that part.

We will be shipping products with some kind of insulator between the battery and holder just to make sure. I also use diodes to power the micro when power is available so I don't drain the coin cell.

boB

>
> ----- Original Message -----
> From: kevin_townsend2
> To: l...@yahoogroups.com
> Sent: Friday, November 06, 2009 9:56 PM
> Subject: [lpc2000] Life Expectancy of CR2032 Battery w/RTC
>
> I was wondering if anyone here has any concrete experience with how long you can expect a (decent quality) CR2032 to work connected to RTXC/VBAT on something like a 2148? I was using RTC to wake the device up regularly, send some data, and then drop back into low power mode, but I don't really know how long I should expect the battery to survive ... obviously one day or another the device just isn't going to 'wake up' anymore. I would assume something like 1-2 years should be OK?
>
>
>
> [Non-text portions of this message have been removed]
>

------------------------------------



(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )

Bob/Leo:

Thanks for the input. I was planning on doing the same when power is available to preserve the batteries. If I can get a year out of them, though, that should be reasonable.

Kevin.

--- In l...@yahoogroups.com, "bobtransformer" wrote:
>
> --- In l...@yahoogroups.com, "Leo" wrote:
> >
> > One year if the battery is sourcing all time. 200mA (CR2032) and 20uA internal RTC.
> >
> > leomecma
> > I measure the operating current into a LPC2366 part as 18 microAmps. (0.0000178 A) (0.178V/10K) The CR2032 battery is 230 mA-hour capacity so that should work out to be (theoretically) about 12,900 hours... Or, 1 and 1/2 years ! (17 months)
>
> I haven't seen mine last for more than a few months on an LPC2103, but I never did measure the current draw on that part.
>
> We will be shipping products with some kind of insulator between the battery and holder just to make sure. I also use diodes to power the micro when power is available so I don't drain the coin cell.
>
> boB
> >
> > ----- Original Message -----
> > From: kevin_townsend2
> > To: l...@yahoogroups.com
> > Sent: Friday, November 06, 2009 9:56 PM
> > Subject: [lpc2000] Life Expectancy of CR2032 Battery w/RTC
> >
> >
> >
> > I was wondering if anyone here has any concrete experience with how long you can expect a (decent quality) CR2032 to work connected to RTXC/VBAT on something like a 2148? I was using RTC to wake the device up regularly, send some data, and then drop back into low power mode, but I don't really know how long I should expect the battery to survive ... obviously one day or another the device just isn't going to 'wake up' anymore. I would assume something like 1-2 years should be OK?
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
>

------------------------------------



(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )

I am using an LPC2368 on a handheld device with a 2032 for the RTC and
NVRAM for the settings. I expected the battery to last 1 year, but
have had these in the field now for 1.5 years without a failure.
------------------------------------

______________________________
Stellaris® MCU Family: New Parts, New Package, New Price.


(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )

I'm surprised no one has considered using rechargeable lithium coin cells.=
=C2=A0 I've been using the Panasonic ML series (DigiKey) in products for ye=
ars in RTC applications.=C2=A0 They keep at full charge while power is appl=
ied.=C2=A0 A dead battery (2.5V)=C2=A0usually takes about 24 hours to fully=
recharge.=C2=A0 From 3.3V, all you need is a current limiting charge resis=
tor, replacing the usual isolation diode in the circuit.
=C2=A0
...kevin

--- On Sat, 11/7/09, kevin_townsend2 wrote:
From: kevin_townsend2
Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
To: l...@yahoogroups.com
Date: Saturday, November 7, 2009, 7:35 AM
=C2=A0=20

Bob/Leo:

Thanks for the input. I was planning on doing the same when power is availa=
ble to preserve the batteries. If I can get a year out of them, though, tha=
t should be reasonable.

Kevin.

--- In lpc2000@yahoogroups .com, "bobtransformer" wrote:
>
>=20
>=20
> --- In lpc2000@yahoogroups .com, "Leo" wrote:
> >
> > One year if the battery is sourcing all time. 200mA (CR2032) and 20uA i=
nternal RTC.
> >=20
> > leomecma
> >=20
>=20
>=20
>=20
> I measure the operating current into a LPC2366 part as 18 microAmps. (0.0=
000178 A) (0.178V/10K) The CR2032 battery is 230 mA-hour capacity so that s=
hould work out to be (theoretically) about 12,900 hours... Or, 1 and 1/2 ye=
ars ! (17 months)
>=20
> I haven't seen mine last for more than a few months on an LPC2103, but I =
never did measure the current draw on that part.
>=20
> We will be shipping products with some kind of insulator between the batt=
ery and holder just to make sure. I also use diodes to power the micro when=
power is available so I don't drain the coin cell.
>=20
> boB
>=20
>=20
>=20
>=20
> >=20
> > ----- Original Message -----=20
> > From: kevin_townsend2=20
> > To: lpc2000@yahoogroups .com=20
> > Sent: Friday, November 06, 2009 9:56 PM
> > Subject: [lpc2000] Life Expectancy of CR2032 Battery w/RTC
> >=20
> >=20
> >=20
> > I was wondering if anyone here has any concrete experience with how lon=
g you can expect a (decent quality) CR2032 to work connected to RTXC/VBAT o=
n something like a 2148? I was using RTC to wake the device up regularly, s=
end some data, and then drop back into low power mode, but I don't really k=
now how long I should expect the battery to survive ... obviously one day o=
r another the device just isn't going to 'wake up' anymore. I would assume =
something like 1-2 years should be OK?
> >=20
> >=20
> >=20
> >=20
> >=20
> > [Non-text portions of this message have been removed]
>

[Non-text portions of this message have been removed]

------------------------------------



(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )

--- In l...@yahoogroups.com, Kevin Braun wrote:
>
> I'm surprised no one has considered using rechargeable lithium coin cells=
.=C2=A0 I've been using the Panasonic ML series (DigiKey) in products for y=
ears in RTC applications.=C2=A0 They keep at full charge while power is app=
lied.=C2=A0 A dead battery (2.5V)=C2=A0usually takes about 24 hours to full=
y recharge.=C2=A0 From 3.3V, all you need is a current limiting charge resi=
stor, replacing the usual isolation diode in the circuit.
> =C2=A0!
> ...kevin

Now, that may just be the best idea I've heard yet !
Would take a slightly more complicated circuit, but probably
not to bad. You may have to charge it off your 5 volt line
somehow though. Maybe not ?

boB

>=20
> --- On Sat, 11/7/09, kevin_townsend2 wrote:
>=20
>=20
> From: kevin_townsend2
> Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> To: l...@yahoogroups.com
> Date: Saturday, November 7, 2009, 7:35 AM
>=20
>=20
> =C2=A0=20
>=20
>=20
>=20
> Bob/Leo:
>=20
> Thanks for the input. I was planning on doing the same when power is avai=
lable to preserve the batteries. If I can get a year out of them, though, t=
hat should be reasonable.
>=20
> Kevin.
>=20
> --- In lpc2000@yahoogroups .com, "bobtransformer" wrote:
> >
> >=20
> >=20
> > --- In lpc2000@yahoogroups .com, "Leo" wrote:
> > >
> > > One year if the battery is sourcing all time. 200mA (CR2032) and 20uA=
internal RTC.
> > >=20
> > > leomecma
> > >=20
> >=20
> >=20
> >=20
> > I measure the operating current into a LPC2366 part as 18 microAmps. (0=
.0000178 A) (0.178V/10K) The CR2032 battery is 230 mA-hour capacity so that=
should work out to be (theoretically) about 12,900 hours... Or, 1 and 1/2 =
years ! (17 months)
> >=20
> > I haven't seen mine last for more than a few months on an LPC2103, but =
I never did measure the current draw on that part.
> >=20
> > We will be shipping products with some kind of insulator between the ba=
ttery and holder just to make sure. I also use diodes to power the micro wh=
en power is available so I don't drain the coin cell.
> >=20
> > boB
> >=20
> >=20
> >=20
> >=20
> > >=20
> > > ----- Original Message -----=20
> > > From: kevin_townsend2=20
> > > To: lpc2000@yahoogroups .com=20
> > > Sent: Friday, November 06, 2009 9:56 PM
> > > Subject: [lpc2000] Life Expectancy of CR2032 Battery w/RTC
> > >=20
> > >=20
> > >=20
> > > I was wondering if anyone here has any concrete experience with how l=
ong you can expect a (decent quality) CR2032 to work connected to RTXC/VBAT=
on something like a 2148? I was using RTC to wake the device up regularly,=
send some data, and then drop back into low power mode, but I don't really=
know how long I should expect the battery to survive ... obviously one day=
or another the device just isn't going to 'wake up' anymore. I would assum=
e something like 1-2 years should be OK?
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > > [Non-text portions of this message have been removed]
> > >
> >
>=20
>=20
>=20
>=20
>=20
>=20
>=20
>=20
> [Non-text portions of this message have been removed]
>

------------------------------------

______________________________
Stellaris® MCU Family: New Parts, New Package, New Price.


(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )

Bob,
You charge them=C2=A0with 3.3V.=C2=A0 If you use 5V, you'll need a 3.3V Zen=
er or Regulator.=C2=A0 Remember, you're charging them with 10's of microamp=
s of current.=C2=A0 As the cell gets close to full, it consumes less curren=
t until it reaches the 3.3V rail.
=C2=A0
In most circuits, you'd susbstiute the isolation diode with a resistor.=C2=
=A0 That's it. The size of the resistor depends on the cell you choose and =
it's maximum allowable charging current.=C2=A0 Just follow the directions :=
-)=C2=A0=20
=C2=A0
If you are doing a production circuit and have to deal with UL/CSA or TUV, =
then use two resistors of equal value.=C2=A0 That satisfies UL's requiremen=
t should one resistor short out.
=C2=A0
...kevin

--- On Sat, 11/7/09, bobtransformer wrote:
From: bobtransformer
Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
To: l...@yahoogroups.com
Date: Saturday, November 7, 2009, 10:50 AM
=C2=A0=20

--- In lpc2000@yahoogroups .com, Kevin Braun wrote:
>
> I'm surprised no one has considered using rechargeable lithium coin cells=
.=C3=82=C2=A0 I've been using the Panasonic ML series (DigiKey) in products=
for years in RTC applications.=C3=82=C2=A0 They keep at full charge while =
power is applied.=C3=82=C2=A0 A dead battery (2.5V)=C3=82=C2=A0usually take=
s about 24 hours to fully recharge.=C3=82=C2=A0 From 3.3V, all you need is =
a current limiting charge resistor, replacing the usual isolation diode in =
the circuit.
> =C3=82=C2=A0!
> ...kevin

Now, that may just be the best idea I've heard yet !
Would take a slightly more complicated circuit, but probably
not to bad. You may have to charge it off your 5 volt line
somehow though. Maybe not ?

boB

>=20
> --- On Sat, 11/7/09, kevin_townsend2 wrote:
>=20
>=20
> From: kevin_townsend2
> Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> To: lpc2000@yahoogroups .com
> Date: Saturday, November 7, 2009, 7:35 AM
>=20
>=20
> =C3=82=C2=A0=20
>=20
>=20
>=20
> Bob/Leo:
>=20
> Thanks for the input. I was planning on doing the same when power is avai=
lable to preserve the batteries. If I can get a year out of them, though, t=
hat should be reasonable.
>=20
> Kevin.
>=20
> --- In lpc2000@yahoogroups .com, "bobtransformer" wrote:
> >
> >=20
> >=20
> > --- In lpc2000@yahoogroups .com, "Leo" wrote:
> > >
> > > One year if the battery is sourcing all time. 200mA (CR2032) and 20uA=
internal RTC.
> > >=20
> > > leomecma
> > >=20
> >=20
> >=20
> >=20
> > I measure the operating current into a LPC2366 part as 18 microAmps. (0=
.0000178 A) (0.178V/10K) The CR2032 battery is 230 mA-hour capacity so that=
should work out to be (theoretically) about 12,900 hours... Or, 1 and 1/2 =
years ! (17 months)
> >=20
> > I haven't seen mine last for more than a few months on an LPC2103, but =
I never did measure the current draw on that part.
> >=20
> > We will be shipping products with some kind of insulator between the ba=
ttery and holder just to make sure. I also use diodes to power the micro wh=
en power is available so I don't drain the coin cell.
> >=20
> > boB
> >=20
> >=20
> >=20
> >=20
> > >=20
> > > ----- Original Message -----=20
> > > From: kevin_townsend2=20
> > > To: lpc2000@yahoogroups .com=20
> > > Sent: Friday, November 06, 2009 9:56 PM
> > > Subject: [lpc2000] Life Expectancy of CR2032 Battery w/RTC
> > >=20
> > >=20
> > >=20
> > > I was wondering if anyone here has any concrete experience with how l=
ong you can expect a (decent quality) CR2032 to work connected to RTXC/VBAT=
on something like a 2148? I was using RTC to wake the device up regularly,=
send some data, and then drop back into low power mode, but I don't really=
know how long I should expect the battery to survive ... obviously one day=
or another the device just isn't going to 'wake up' anymore. I would assum=
e something like 1-2 years should be OK?
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > > [Non-text portions of this message have been removed]
> > >
> >
>=20
>=20
>=20
>=20
>=20
>=20
>=20
>=20
> [Non-text portions of this message have been removed]
>

[Non-text portions of this message have been removed]

------------------------------------



(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )

Oops!!!
I shot my mouth too soon.=C2=A0 You do need an isolation diode to the 3.3V =
rail.=C2=A0 Use a low leakage schottky like the SD101.
=C2=A0
...kevin

--- On Sat, 11/7/09, Kevin Braun wrote:
From: Kevin Braun
Subject: Re: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
To: l...@yahoogroups.com
Date: Saturday, November 7, 2009, 11:34 AM

Bob,
You charge them=C2=A0with 3.3V.=C2=A0 If you use 5V, you'll need a 3.3V Zen=
er or Regulator.=C2=A0 Remember, you're charging them with 10's of microamp=
s of current.=C2=A0 As the cell gets close to full, it consumes less curren=
t until it reaches the 3.3V rail.
=C2=A0
In most circuits, you'd susbstiute the isolation diode with a resistor.=C2=
=A0 That's it. The size of the resistor depends on the cell you choose and =
it's maximum allowable charging current.=C2=A0 Just follow the directions :=
-)=C2=A0=20
=C2=A0
If you are doing a production circuit and have to deal with UL/CSA or TUV, =
then use two resistors of equal value.=C2=A0 That satisfies UL's requiremen=
t should one resistor short out.
=C2=A0
...kevin

--- On Sat, 11/7/09, bobtransformer wrote:
From: bobtransformer
Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
To: l...@yahoogroups.com
Date: Saturday, November 7, 2009, 10:50 AM
=C2=A0=20

--- In lpc2000@yahoogroups .com, Kevin Braun wrote:
>
> I'm surprised no one has considered using rechargeable lithium coin cells=
.=C3=82=C2=A0 I've been using the Panasonic ML series (DigiKey) in products=
for years in RTC applications.=C3=82=C2=A0 They keep at full charge while =
power is applied.=C3=82=C2=A0 A dead battery (2.5V)=C3=82=C2=A0usually take=
s about 24 hours to fully recharge.=C3=82=C2=A0 From 3.3V, all you need is =
a current limiting charge resistor, replacing the usual isolation diode in =
the circuit.
> =C3=82=C2=A0!
> ...kevin

Now, that may just be the best idea I've heard yet !
Would take a slightly more complicated circuit, but probably
not to bad. You may have to charge it off your 5 volt line
somehow though. Maybe not ?

boB

>=20
> --- On Sat, 11/7/09, kevin_townsend2 wrote:
>=20
>=20
> From: kevin_townsend2
> Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> To: lpc2000@yahoogroups .com
> Date: Saturday, November 7, 2009, 7:35 AM
>=20
>=20
> =C3=82=C2=A0=20
>=20
>=20
>=20
> Bob/Leo:
>=20
> Thanks for the input. I was planning on doing the same when power is avai=
lable to preserve the batteries. If I can get a year out of them, though, t=
hat should be reasonable.
>=20
> Kevin.
>=20
> --- In lpc2000@yahoogroups .com, "bobtransformer" wrote:
> >
> >=20
> >=20
> > --- In lpc2000@yahoogroups .com, "Leo" wrote:
> > >
> > > One year if the battery is sourcing all time. 200mA (CR2032) and 20uA=
internal RTC.
> > >=20
> > > leomecma
> > >=20
> >=20
> >=20
> >=20
> > I measure the operating current into a LPC2366 part as 18 microAmps. (0=
.0000178 A) (0.178V/10K) The CR2032 battery is 230 mA-hour capacity so that=
should work out to be (theoretically) about 12,900 hours... Or, 1 and 1/2 =
years ! (17 months)
> >=20
> > I haven't seen mine last for more than a few months on an LPC2103, but =
I never did measure the current draw on that part.
> >=20
> > We will be shipping products with some kind of insulator between the ba=
ttery and holder just to make sure. I also use diodes to power the micro wh=
en power is available so I don't drain the coin cell.
> >=20
> > boB
> >=20
> >=20
> >=20
> >=20
> > >=20
> > > ----- Original Message -----=20
> > > From: kevin_townsend2=20
> > > To: lpc2000@yahoogroups .com=20
> > > Sent: Friday, November 06, 2009 9:56 PM
> > > Subject: [lpc2000] Life Expectancy of CR2032 Battery w/RTC
> > >=20
> > >=20
> > >=20
> > > I was wondering if anyone here has any concrete experience with how l=
ong you can expect a (decent quality) CR2032 to work connected to RTXC/VBAT=
on something like a 2148? I was using RTC to wake the device up regularly,=
send some data, and then drop back into low power mode, but I don't really=
know how long I should expect the battery to survive ... obviously one day=
or another the device just isn't going to 'wake up' anymore. I would assum=
e something like 1-2 years should be OK?
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > > [Non-text portions of this message have been removed]
> > >
> >
>=20
>=20
>=20
>=20
>=20
>=20
>=20
>=20
> [Non-text portions of this message have been removed]
>

[Non-text portions of this message have been removed]

------------------------------------



(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )

The Panasonic ML614R specification say:
Continuous standard load (mA) =3D 0.01 ( 10uA )=20=20
RTC current of LPC2XXX is approximately 18uA ! !
=20
Fabrizio=20

--- In l...@yahoogroups.com, Kevin Braun wrote:
>
> Oops!!!
> I shot my mouth too soon.=C2=A0 You do need an isolation diode to the 3.3=
V rail.=C2=A0 Use a low leakage schottky like the SD101.
> =C2=A0
> ...kevin
>=20
> --- On Sat, 11/7/09, Kevin Braun wrote:
>=20
>=20
> From: Kevin Braun
> Subject: Re: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> To: l...@yahoogroups.com
> Date: Saturday, November 7, 2009, 11:34 AM
>=20
>=20
>=20
>=20
>=20
>=20
>=20
> Bob,
> You charge them=C2=A0with 3.3V.=C2=A0 If you use 5V, you'll need a 3.3V Z=
ener or Regulator.=C2=A0 Remember, you're charging them with 10's of microa=
mps of current.=C2=A0 As the cell gets close to full, it consumes less curr=
ent until it reaches the 3.3V rail.
> =C2=A0
> In most circuits, you'd susbstiute the isolation diode with a resistor.=
=C2=A0 That's it. The size of the resistor depends on the cell you choose a=
nd it's maximum allowable charging current.=C2=A0 Just follow the direction=
s :-)=C2=A0=20
> =C2=A0
> If you are doing a production circuit and have to deal with UL/CSA or TUV=
, then use two resistors of equal value.=C2=A0 That satisfies UL's requirem=
ent should one resistor short out.
> =C2=A0
> ...kevin
>=20
> --- On Sat, 11/7/09, bobtransformer wrote:
>=20
>=20
> From: bobtransformer
> Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> To: l...@yahoogroups.com
> Date: Saturday, November 7, 2009, 10:50 AM
>=20
>=20
> =C2=A0=20
>=20
>=20
>=20
>=20
>=20
> --- In lpc2000@yahoogroups .com, Kevin Braun wrote:
> >
> > I'm surprised no one has considered using rechargeable lithium coin cel=
ls.=C3=82=C2=A0 I've been using the Panasonic ML series (DigiKey) in produc=
ts for years in RTC applications.=C3=82=C2=A0 They keep at full charge whil=
e power is applied.=C3=82=C2=A0 A dead battery (2.5V)=C3=82=C2=A0usually ta=
kes about 24 hours to fully recharge.=C3=82=C2=A0 From 3.3V, all you need i=
s a current limiting charge resistor, replacing the usual isolation diode i=
n the circuit.
> > =C3=82=C2=A0!
> > ...kevin
>=20
> Now, that may just be the best idea I've heard yet !
> Would take a slightly more complicated circuit, but probably
> not to bad. You may have to charge it off your 5 volt line
> somehow though. Maybe not ?
>=20
> boB
>=20
> >=20
> > --- On Sat, 11/7/09, kevin_townsend2 wrote:
> >=20
> >=20
> > From: kevin_townsend2
> > Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> > To: lpc2000@yahoogroups .com
> > Date: Saturday, November 7, 2009, 7:35 AM
> >=20
> >=20
> > =C3=82=C2=A0=20
> >=20
> >=20
> >=20
> > Bob/Leo:
> >=20
> > Thanks for the input. I was planning on doing the same when power is av=
ailable to preserve the batteries. If I can get a year out of them, though,=
that should be reasonable.
> >=20
> > Kevin.
> >=20
> > --- In lpc2000@yahoogroups .com, "bobtransformer" wrote:
> > >
> > >=20
> > >=20
> > > --- In lpc2000@yahoogroups .com, "Leo" wrote:
> > > >
> > > > One year if the battery is sourcing all time. 200mA (CR2032) and 20=
uA internal RTC.
> > > >=20
> > > > leomecma
> > > >=20
> > >=20
> > >=20
> > >=20
> > > I measure the operating current into a LPC2366 part as 18 microAmps. =
(0.0000178 A) (0.178V/10K) The CR2032 battery is 230 mA-hour capacity so th=
at should work out to be (theoretically) about 12,900 hours... Or, 1 and 1/=
2 years ! (17 months)
> > >=20
> > > I haven't seen mine last for more than a few months on an LPC2103, bu=
t I never did measure the current draw on that part.
> > >=20
> > > We will be shipping products with some kind of insulator between the =
battery and holder just to make sure. I also use diodes to power the micro =
when power is available so I don't drain the coin cell.
> > >=20
> > > boB
> > >=20
> > >=20
> > >=20
> > >=20
> > > >=20
> > > > ----- Original Message -----=20
> > > > From: kevin_townsend2=20
> > > > To: lpc2000@yahoogroups .com=20
> > > > Sent: Friday, November 06, 2009 9:56 PM
> > > > Subject: [lpc2000] Life Expectancy of CR2032 Battery w/RTC
> > > >=20
> > > >=20
> > > >=20
> > > > I was wondering if anyone here has any concrete experience with how=
long you can expect a (decent quality) CR2032 to work connected to RTXC/VB=
AT on something like a 2148? I was using RTC to wake the device up regularl=
y, send some data, and then drop back into low power mode, but I don't real=
ly know how long I should expect the battery to survive ... obviously one d=
ay or another the device just isn't going to 'wake up' anymore. I would ass=
ume something like 1-2 years should be OK?
> > > >=20
> > > >=20
> > > >=20
> > > >=20
> > > >=20
> > > > [Non-text portions of this message have been removed]
> > > >
> > >
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> > [Non-text portions of this message have been removed]
> >
>=20
>=20
>=20
>=20
>=20
>=20
>=20
>=20
> [Non-text portions of this message have been removed]
>

------------------------------------



(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )

I saw that Digikey also won't ship those batteries outside the US (probably=
because of some new airmail restrictions in Lithium). They looked interes=
ting, but it seems fate (or maybe just some EU technocrats) are pushing me =
towards standard CR2032 cells.

Kevin.

--- In l...@yahoogroups.com, "f_bracalenti_technika_it" .> wrote:
>
>=20
> The Panasonic ML614R specification say:
> Continuous standard load (mA) =3D 0.01 ( 10uA )=20=20
> RTC current of LPC2XXX is approximately 18uA ! !
>=20=20
> Fabrizio=20
>=20
> --- In l...@yahoogroups.com, Kevin Braun wrote:
> >
> > Oops!!!
> > I shot my mouth too soon.=C2=A0 You do need an isolation diode to the 3=
.3V rail.=C2=A0 Use a low leakage schottky like the SD101.
> > =C2=A0
> > ...kevin
> >=20
> > --- On Sat, 11/7/09, Kevin Braun wrote:
> >=20
> >=20
> > From: Kevin Braun
> > Subject: Re: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> > To: l...@yahoogroups.com
> > Date: Saturday, November 7, 2009, 11:34 AM
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> > Bob,
> > You charge them=C2=A0with 3.3V.=C2=A0 If you use 5V, you'll need a 3.3V=
Zener or Regulator.=C2=A0 Remember, you're charging them with 10's of micr=
oamps of current.=C2=A0 As the cell gets close to full, it consumes less cu=
rrent until it reaches the 3.3V rail.
> > =C2=A0
> > In most circuits, you'd susbstiute the isolation diode with a resistor.=
=C2=A0 That's it. The size of the resistor depends on the cell you choose a=
nd it's maximum allowable charging current.=C2=A0 Just follow the direction=
s :-)=C2=A0=20
> > =C2=A0
> > If you are doing a production circuit and have to deal with UL/CSA or T=
UV, then use two resistors of equal value.=C2=A0 That satisfies UL's requir=
ement should one resistor short out.
> > =C2=A0
> > ...kevin
> >=20
> > --- On Sat, 11/7/09, bobtransformer wrote:
> >=20
> >=20
> > From: bobtransformer
> > Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> > To: l...@yahoogroups.com
> > Date: Saturday, November 7, 2009, 10:50 AM
> >=20
> >=20
> > =C2=A0=20
> >=20
> >=20
> >=20
> >=20
> >=20
> > --- In lpc2000@yahoogroups .com, Kevin Braun wrote:
> > >
> > > I'm surprised no one has considered using rechargeable lithium coin c=
ells.=C3=82=C2=A0 I've been using the Panasonic ML series (DigiKey) in prod=
ucts for years in RTC applications.=C3=82=C2=A0 They keep at full charge wh=
ile power is applied.=C3=82=C2=A0 A dead battery (2.5V)=C3=82=C2=A0usually =
takes about 24 hours to fully recharge.=C3=82=C2=A0 From 3.3V, all you need=
is a current limiting charge resistor, replacing the usual isolation diode=
in the circuit.
> > > =C3=82=C2=A0!
> > > ...kevin
> >=20
> > Now, that may just be the best idea I've heard yet !
> > Would take a slightly more complicated circuit, but probably
> > not to bad. You may have to charge it off your 5 volt line
> > somehow though. Maybe not ?
> >=20
> > boB
> >=20
> > >=20
> > > --- On Sat, 11/7/09, kevin_townsend2 wrote:
> > >=20
> > >=20
> > > From: kevin_townsend2
> > > Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> > > To: lpc2000@yahoogroups .com
> > > Date: Saturday, November 7, 2009, 7:35 AM
> > >=20
> > >=20
> > > =C3=82=C2=A0=20
> > >=20
> > >=20
> > >=20
> > > Bob/Leo:
> > >=20
> > > Thanks for the input. I was planning on doing the same when power is =
available to preserve the batteries. If I can get a year out of them, thoug=
h, that should be reasonable.
> > >=20
> > > Kevin.
> > >=20
> > > --- In lpc2000@yahoogroups .com, "bobtransformer" wrote:
> > > >
> > > >=20
> > > >=20
> > > > --- In lpc2000@yahoogroups .com, "Leo" wrote:
> > > > >
> > > > > One year if the battery is sourcing all time. 200mA (CR2032) and =
20uA internal RTC.
> > > > >=20
> > > > > leomecma
> > > > >=20
> > > >=20
> > > >=20
> > > >=20
> > > > I measure the operating current into a LPC2366 part as 18 microAmps=
. (0.0000178 A) (0.178V/10K) The CR2032 battery is 230 mA-hour capacity so =
that should work out to be (theoretically) about 12,900 hours... Or, 1 and =
1/2 years ! (17 months)
> > > >=20
> > > > I haven't seen mine last for more than a few months on an LPC2103, =
but I never did measure the current draw on that part.
> > > >=20
> > > > We will be shipping products with some kind of insulator between th=
e battery and holder just to make sure. I also use diodes to power the micr=
o when power is available so I don't drain the coin cell.
> > > >=20
> > > > boB
> > > >=20
> > > >=20
> > > >=20
> > > >=20
> > > > >=20
> > > > > ----- Original Message -----=20
> > > > > From: kevin_townsend2=20
> > > > > To: lpc2000@yahoogroups .com=20
> > > > > Sent: Friday, November 06, 2009 9:56 PM
> > > > > Subject: [lpc2000] Life Expectancy of CR2032 Battery w/RTC
> > > > >=20
> > > > >=20
> > > > >=20
> > > > > I was wondering if anyone here has any concrete experience with h=
ow long you can expect a (decent quality) CR2032 to work connected to RTXC/=
VBAT on something like a 2148? I was using RTC to wake the device up regula=
rly, send some data, and then drop back into low power mode, but I don't re=
ally know how long I should expect the battery to survive ... obviously one=
day or another the device just isn't going to 'wake up' anymore. I would a=
ssume something like 1-2 years should be OK?
> > > > >=20
> > > > >=20
> > > > >=20
> > > > >=20
> > > > >=20
> > > > > [Non-text portions of this message have been removed]
> > > > >
> > > >
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > > [Non-text portions of this message have been removed]
> > >
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> > [Non-text portions of this message have been removed]
>

------------------------------------



(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )

--- In l...@yahoogroups.com, "f_bracalenti_technika_it" .> wrote:
>
>=20
> The Panasonic ML614R specification say:
> Continuous standard load (mA) =3D 0.01 ( 10uA )=20=20
> RTC current of LPC2XXX is approximately 18uA ! !
>=20=20
> Fabrizio=20
>=20

OK then.... How about using 2 (two) ML6124R batteries in parallel !
A bit overboard, but could work.

boB

> --- In l...@yahoogroups.com, Kevin Braun wrote:
> >
> > Oops!!!
> > I shot my mouth too soon.=C2=A0 You do need an isolation diode to the 3=
.3V rail.=C2=A0 Use a low leakage schottky like the SD101.
> > =C2=A0
> > ...kevin
> >=20
> > --- On Sat, 11/7/09, Kevin Braun wrote:
> >=20
> >=20
> > From: Kevin Braun
> > Subject: Re: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> > To: l...@yahoogroups.com
> > Date: Saturday, November 7, 2009, 11:34 AM
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> > Bob,
> > You charge them=C2=A0with 3.3V.=C2=A0 If you use 5V, you'll need a 3.3V=
Zener or Regulator.=C2=A0 Remember, you're charging them with 10's of micr=
oamps of current.=C2=A0 As the cell gets close to full, it consumes less cu=
rrent until it reaches the 3.3V rail.
> > =C2=A0
> > In most circuits, you'd susbstiute the isolation diode with a resistor.=
=C2=A0 That's it. The size of the resistor depends on the cell you choose a=
nd it's maximum allowable charging current.=C2=A0 Just follow the direction=
s :-)=C2=A0=20
> > =C2=A0
> > If you are doing a production circuit and have to deal with UL/CSA or T=
UV, then use two resistors of equal value.=C2=A0 That satisfies UL's requir=
ement should one resistor short out.
> > =C2=A0
> > ...kevin
> >=20
> > --- On Sat, 11/7/09, bobtransformer wrote:
> >=20
> >=20
> > From: bobtransformer
> > Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> > To: l...@yahoogroups.com
> > Date: Saturday, November 7, 2009, 10:50 AM
> >=20
> >=20
> > =C2=A0=20
> >=20
> >=20
> >=20
> >=20
> >=20
> > --- In lpc2000@yahoogroups .com, Kevin Braun wrote:
> > >
> > > I'm surprised no one has considered using rechargeable lithium coin c=
ells.=C3=82=C2=A0 I've been using the Panasonic ML series (DigiKey) in prod=
ucts for years in RTC applications.=C3=82=C2=A0 They keep at full charge wh=
ile power is applied.=C3=82=C2=A0 A dead battery (2.5V)=C3=82=C2=A0usually =
takes about 24 hours to fully recharge.=C3=82=C2=A0 From 3.3V, all you need=
is a current limiting charge resistor, replacing the usual isolation diode=
in the circuit.
> > > =C3=82=C2=A0!
> > > ...kevin
> >=20
> > Now, that may just be the best idea I've heard yet !
> > Would take a slightly more complicated circuit, but probably
> > not to bad. You may have to charge it off your 5 volt line
> > somehow though. Maybe not ?
> >=20
> > boB
> >=20
> > >=20
> > > --- On Sat, 11/7/09, kevin_townsend2 wrote:
> > >=20
> > >=20
> > > From: kevin_townsend2
> > > Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> > > To: lpc2000@yahoogroups .com
> > > Date: Saturday, November 7, 2009, 7:35 AM
> > >=20
> > >=20
> > > =C3=82=C2=A0=20
> > >=20
> > >=20
> > >=20
> > > Bob/Leo:
> > >=20
> > > Thanks for the input. I was planning on doing the same when power is =
available to preserve the batteries. If I can get a year out of them, thoug=
h, that should be reasonable.
> > >=20
> > > Kevin.
> > >=20
> > > --- In lpc2000@yahoogroups .com, "bobtransformer" wrote:
> > > >
> > > >=20
> > > >=20
> > > > --- In lpc2000@yahoogroups .com, "Leo" wrote:
> > > > >
> > > > > One year if the battery is sourcing all time. 200mA (CR2032) and =
20uA internal RTC.
> > > > >=20
> > > > > leomecma
> > > > >=20
> > > >=20
> > > >=20
> > > >=20
> > > > I measure the operating current into a LPC2366 part as 18 microAmps=
. (0.0000178 A) (0.178V/10K) The CR2032 battery is 230 mA-hour capacity so =
that should work out to be (theoretically) about 12,900 hours... Or, 1 and =
1/2 years ! (17 months)
> > > >=20
> > > > I haven't seen mine last for more than a few months on an LPC2103, =
but I never did measure the current draw on that part.
> > > >=20
> > > > We will be shipping products with some kind of insulator between th=
e battery and holder just to make sure. I also use diodes to power the micr=
o when power is available so I don't drain the coin cell.
> > > >=20
> > > > boB
> > > >=20
> > > >=20
> > > >=20
> > > >=20
> > > > >=20
> > > > > ----- Original Message -----=20
> > > > > From: kevin_townsend2=20
> > > > > To: lpc2000@yahoogroups .com=20
> > > > > Sent: Friday, November 06, 2009 9:56 PM
> > > > > Subject: [lpc2000] Life Expectancy of CR2032 Battery w/RTC
> > > > >=20
> > > > >=20
> > > > >=20
> > > > > I was wondering if anyone here has any concrete experience with h=
ow long you can expect a (decent quality) CR2032 to work connected to RTXC/=
VBAT on something like a 2148? I was using RTC to wake the device up regula=
rly, send some data, and then drop back into low power mode, but I don't re=
ally know how long I should expect the battery to survive ... obviously one=
day or another the device just isn't going to 'wake up' anymore. I would a=
ssume something like 1-2 years should be OK?
> > > > >=20
> > > > >=20
> > > > >=20
> > > > >=20
> > > > >=20
> > > > > [Non-text portions of this message have been removed]
> > > > >
> > > >
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > > [Non-text portions of this message have been removed]
> > >
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> > [Non-text portions of this message have been removed]
>

------------------------------------



(You need to be a member of lpc2000 -- send a blank email to lpc2000-subscribe@yahoogroups.com )

Here's what to expect from these cells with a 20uA load...
=C2=A0
ML-2020=C2=A0=C2=A0 90 days
ML-1220=C2=A0=C2=A0 55 days
ML-920=C2=A0=C2=A0=C2=A0=C2=A018 days
ML-614=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 8 days
ML-612=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 5 days
=C2=A0
The other cells in this family didn't have uA/day graphs in them.
=C2=A0
BTW:=C2=A0 20uA is extremely high=C2=A0for a RTC in backup mode.=C2=A0 Part=
s I've dealt with are routinely 500nA.
=C2=A0
...kevin
=C2=A0=C2=A0=C2=A0
--- On Mon, 11/9/09, bobtransformer wrote:
From: bobtransformer
Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
To: l...@yahoogroups.com
Date: Monday, November 9, 2009, 10:59 AM
=C2=A0=20

--- In lpc2000@yahoogroups .com, "f_bracalenti_ technika_ it" @ ...> wrote:
>
>=20
> The Panasonic ML614R specification say:
> Continuous standard load (mA) =3D 0.01 ( 10uA )=20
> RTC current of LPC2XXX is approximately 18uA ! !
>=20
> Fabrizio=20
>=20

OK then.... How about using 2 (two) ML6124R batteries in parallel !
A bit overboard, but could work.

boB

> --- In lpc2000@yahoogroups .com, Kevin Braun wrote:
> >
> > Oops!!!
> > I shot my mouth too soon.=C3=82=C2=A0 You do need an isolation diode to=
the 3.3V rail.=C3=82=C2=A0 Use a low leakage schottky like the SD101.
> > =C3=82=C2=A0
> > ...kevin
> >=20
> > --- On Sat, 11/7/09, Kevin Braun wrote:
> >=20
> >=20
> > From: Kevin Braun
> > Subject: Re: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> > To: lpc2000@yahoogroups .com
> > Date: Saturday, November 7, 2009, 11:34 AM
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> > Bob,
> > You charge them=C3=82=C2=A0with 3.3V.=C3=82=C2=A0 If you use 5V, you'll=
need a 3.3V Zener or Regulator.=C3=82=C2=A0 Remember, you're charging them=
with 10's of microamps of current.=C3=82=C2=A0 As the cell gets close to f=
ull, it consumes less current until it reaches the 3.3V rail.
> > =C3=82=C2=A0
> > In most circuits, you'd susbstiute the isolation diode with a resistor.=
=C3=82=C2=A0 That's it. The size of the resistor depends on the cell you ch=
oose and it's maximum allowable charging current.=C3=82=C2=A0 Just follow t=
he directions :-)=C3=82=C2=A0=20
> > =C3=82=C2=A0
> > If you are doing a production circuit and have to deal with UL/CSA or T=
UV, then use two resistors of equal value.=C3=82=C2=A0 That satisfies UL's =
requirement should one resistor short out.
> > =C3=82=C2=A0
> > ...kevin
> >=20
> > --- On Sat, 11/7/09, bobtransformer wrote:
> >=20
> >=20
> > From: bobtransformer
> > Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> > To: lpc2000@yahoogroups .com
> > Date: Saturday, November 7, 2009, 10:50 AM
> >=20
> >=20
> > =C3=82=C2=A0=20
> >=20
> >=20
> >=20
> >=20
> >=20
> > --- In lpc2000@yahoogroups .com, Kevin Braun wrote:
> > >
> > > I'm surprised no one has considered using rechargeable lithium coin c=
ells.=C3=83=E2=80=9A=C3=82=C2=A0 I've been using the Panasonic ML series (D=
igiKey) in products for years in RTC applications.=C3=83=E2=80=9A=C3=82=C2=
=A0 They keep at full charge while power is applied.=C3=83=E2=80=9A=C3=82=
=C2=A0 A dead battery (2.5V)=C3=83=E2=80=9A=C3=82=C2=A0usually takes about =
24 hours to fully recharge.=C3=83=E2=80=9A=C3=82=C2=A0 From 3.3V, all you n=
eed is a current limiting charge resistor, replacing the usual isolation di=
ode in the circuit.
> > > =C3=83=E2=80=9A=C3=82=C2=A0!
> > > ...kevin
> >=20
> > Now, that may just be the best idea I've heard yet !
> > Would take a slightly more complicated circuit, but probably
> > not to bad. You may have to charge it off your 5 volt line
> > somehow though. Maybe not ?
> >=20
> > boB
> >=20
> > >=20
> > > --- On Sat, 11/7/09, kevin_townsend2 wrote:
> > >=20
> > >=20
> > > From: kevin_townsend2
> > > Subject: [lpc2000] Re: Life Expectancy of CR2032 Battery w/RTC
> > > To: lpc2000@yahoogroups .com
> > > Date: Saturday, November 7, 2009, 7:35 AM
> > >=20
> > >=20
> > > =C3=83=E2=80=9A=C3=82=C2=A0=20
> > >=20
> > >=20
> > >=20
> > > Bob/Leo:
> > >=20
> > > Thanks for the input. I was planning on doing the same when power is =
available to preserve the batteries. If I can get a year out of them, thoug=
h, that should be reasonable.
> > >=20
> > > Kevin.
> > >=20
> > > --- In lpc2000@yahoogroups .com, "bobtransformer" wrote:
> > > >
> > > >=20
> > > >=20
> > > > --- In lpc2000@yahoogroups .com, "Leo" wrote:
> > > > >
> > > > > One year if the battery is sourcing all time. 200mA (CR2032) and =
20uA internal RTC.
> > > > >=20
> > > > > leomecma
> > > > >=20
> > > >=20
> > > >=20
> > > >=20
> > > > I measure the operating current into a LPC2366 part as 18 microAmps=
. (0.0000178 A) (0.178V/10K) The CR2032 battery is 230 mA-hour capacity so =
that should work out to be (theoretically) about 12,900 hours... Or, 1 and =
1/2 years ! (17 months)
> > > >=20
> > > > I haven't seen mine last for more than a few months on an LPC2103, =
but I never did measure the current draw on that part.
> > > >=20
> > > > We will be shipping products with some kind of insulator between th=
e battery and holder just to make sure. I also use diodes to power the micr=
o when power is available so I don't drain the coin cell.
> > > >=20
> > > > boB
> > > >=20
> > > >=20
> > > >=20
> > > >=20
> > > > >=20
> > > > > ----- Original Message -----=20
> > > > > From: kevin_townsend2=20
> > > > > To: lpc2000@yahoogroups .com=20
> > > > > Sent: Friday, November 06, 2009 9:56 PM
> > > > > Subject: [lpc2000] Life Expectancy of CR2032 Battery w/RTC
> > > > >=20
> > > > >=20
> > > > >=20
> > > > > I was wondering if anyone here has any concrete experience with h=
ow long you can expect a (decent quality) CR2032 to work connected to RTXC/=
VBAT on something like a 2148? I was using RTC to wake the device up regula=
rly, send some data, and then drop back into low power mode, but I don't re=
ally know how long I should expect the battery to survive ... obviously one=
day or another the device just isn't going to 'wake up' anymore. I would a=
ssume something like 1-2 years should be OK?
> > > > >=20
> > > > >=20
> > > > >=20
> > > > >=20
> > > > >=20
> > > > > [Non-text portions of this message have been removed]
> > > > >
> > > >
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > >=20
> > > [Non-text portions of this message have been removed]
> > >
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> > [Non-text portions of this message have been removed]
>

[Non-text portions of this message have been removed]

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> The Panasonic ML614R specification say:
> Continuous standard load (mA) = 0.01 ( 10uA )
> RTC current of LPC2XXX is approximately 18uA ! !
>
> Fabrizio
>
> --- In l...@yahoogroups.com, Kevin Braun wrote:
> >
> > Oops!!!
> > I shot my mouth too soon. You do need an isolation diode to the 3.3V
> > rail. Use a low leakage schottky like the SD101.
> > Â
> > ...kevin
> >

We use Nicad battery, that was use to come in old (very old) PC mother
board. It's 60mAh 3.6 volts, and charge by a small resistance connected to 5
volt. So never replaced in last 5 years.

Warm Regards,
Mukund Deshmukh,
Beta Computronics Pvt Ltd,
10/1 IT Park, Parsodi,
Nagpur -440022.

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