Wanted - UK source of a replacement battery (type LX 1634) for HP 3457A 6.5 digit multimeter
I've got a HP 3457A 6.5 digit multimeter - S/N 2703A04579. It's working
fine, but I'm aware the battery must be at least 11 years old, as I first
bought the meter 11 years ago. I suspect its due for a change. I'm trying
to find a reputable source for a replacement. I want to avoid eBay, due
to the number of fakes on there.
Opening the meter up, I see the PCB shows "BT 601". There's no name on the
battery I can see, but the type number of LX 1634. The voltage measured on
my 4.5 digit handheld DVM is 3.03 V. Googling around
https://groups.yahoo.com/neo/groups/hp_agilent_equipment/conversations/topics/48964
would suggest the battery was made by Saft and is a Lithium-manganese
dioxide (Li-MnO2). The size appears to be known as 2/3A. One source
suggests a replacment is the Panasonic BR-2/3AE2SP
Mouser's uk site
http://www.mouser.co.uk/
says shipping is restricted, so only available in the USA.
The nearest I've found to anything remotely suitable is actually a 3.6 V
battery
"CROMPTON ETERNACELL T32/8AA8F Battery, Single Cell, Lithium Thionyl
Chloride, 2100 mAh, 3.6 V, 2/3A, Axial Leaded, 16.3 mm"
http://uk.farnell.com/crompton-eternacell/t32-8aa8f/battery-lithium-2-3aa-axial-lead/dp/774017
I'd rather not fit a higher voltage battery, although given it provides
power to some 5 V static RAM, I would not expect it to be a problem. That
said, I believe when on mains power this battery is not needed, so there
may be some circuitry that would not like a 3.7 V battery. When power is on
the unit, there is 4.88 V across the static RAM. As mains is reduced, so
the voltage drops to about 2.8 V. I think there must be a Schottky diode
that stops the battery being drained when the mains power is on.
The battery needs to have either very thin pins or wire-ended. Some I have
seen have tags a 2~3 mm wide, which will not fit in the PCB. Others have 3
terminals, which stops you putting it in the wrong way around, but they
will not fit properly on the PCB.
In applications like the 3457A, when the SRAM needs to be kept alive when
power is off, I wish HP would have put two batteries in holders and diode
-OR'ed them. If they had done that, one could just pull out a battery from
holder A, and put a new one in B. Then when B gets old, put one in A.
My first problem though is finding a suitable battery. Next problem is
changing it without losing the RAM contents, but I don't think that's a big
deal.
The 3.6 V Lithium Thionyl Chloride is very tempting, as it has a higher
capacity than the Lithium-manganese dioxide and they have a very low
self-discharge (1%/year). I'm just not overly happy about fitting a higher
voltage battery than it is supposed to have, but phyysically it fits, and I
can get one easy enough from Farnell in the UK.
Dr. David Kirkby Ph.D CEng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT,
UK.
Registered in England and Wales, company number 08914892.
http://www.kirkbymicrowave.co.uk/
Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please)
I just replaced the battery in my 3457A. From Mouser: Panasonic BR2/3AE2SP
Joe Gray
W5JG
On Sun, Jan 24, 2016 at 12:54 PM, Dr. David Kirkby (Kirkby Microwave
Ltd) drkirkby@kirkbymicrowave.co.uk wrote:
I've got a HP 3457A 6.5 digit multimeter - S/N 2703A04579. It's working
fine, but I'm aware the battery must be at least 11 years old, as I first
bought the meter 11 years ago. I suspect its due for a change. I'm trying
to find a reputable source for a replacement. I want to avoid eBay, due
to the number of fakes on there.
Opening the meter up, I see the PCB shows "BT 601". There's no name on the
battery I can see, but the type number of LX 1634. The voltage measured on
my 4.5 digit handheld DVM is 3.03 V. Googling around
https://groups.yahoo.com/neo/groups/hp_agilent_equipment/conversations/topics/48964
would suggest the battery was made by Saft and is a Lithium-manganese
dioxide (Li-MnO2). The size appears to be known as 2/3A. One source
suggests a replacment is the Panasonic BR-2/3AE2SP
Mouser's uk site
http://www.mouser.co.uk/
says shipping is restricted, so only available in the USA.
The nearest I've found to anything remotely suitable is actually a 3.6 V
battery
"CROMPTON ETERNACELL T32/8AA8F Battery, Single Cell, Lithium Thionyl
Chloride, 2100 mAh, 3.6 V, 2/3A, Axial Leaded, 16.3 mm"
http://uk.farnell.com/crompton-eternacell/t32-8aa8f/battery-lithium-2-3aa-axial-lead/dp/774017
I'd rather not fit a higher voltage battery, although given it provides
power to some 5 V static RAM, I would not expect it to be a problem. That
said, I believe when on mains power this battery is not needed, so there
may be some circuitry that would not like a 3.7 V battery. When power is on
the unit, there is 4.88 V across the static RAM. As mains is reduced, so
the voltage drops to about 2.8 V. I think there must be a Schottky diode
that stops the battery being drained when the mains power is on.
The battery needs to have either very thin pins or wire-ended. Some I have
seen have tags a 2~3 mm wide, which will not fit in the PCB. Others have 3
terminals, which stops you putting it in the wrong way around, but they
will not fit properly on the PCB.
In applications like the 3457A, when the SRAM needs to be kept alive when
power is off, I wish HP would have put two batteries in holders and diode
-OR'ed them. If they had done that, one could just pull out a battery from
holder A, and put a new one in B. Then when B gets old, put one in A.
My first problem though is finding a suitable battery. Next problem is
changing it without losing the RAM contents, but I don't think that's a big
deal.
The 3.6 V Lithium Thionyl Chloride is very tempting, as it has a higher
capacity than the Lithium-manganese dioxide and they have a very low
self-discharge (1%/year). I'm just not overly happy about fitting a higher
voltage battery than it is supposed to have, but phyysically it fits, and I
can get one easy enough from Farnell in the UK.
Dr. David Kirkby Ph.D CEng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, Essex, CM3 6DT,
UK.
Registered in England and Wales, company number 08914892.
http://www.kirkbymicrowave.co.uk/
Tel: 07910 441670 / +44 7910 441670 (0900 to 2100 GMT only please)
volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.
In message CANX10hADbw1u9eJC8_ZgsK94k8Az8vzG4oSe+XnGfWRALi0B0w@mail.gmail.com
, "Dr. David Kirkby (Kirkby Microwave Ltd)" writes:
Opening the meter up, I see the PCB shows "BT 601". There's no name on the
battery I can see, but the type number of LX 1634. The voltage measured on
my 4.5 digit handheld DVM is 3.03 V. Googling around
My guess is that this is a 3.6V Lithium-Thionyl battery, and if it is
only 3.03V now, you're very likely tethering right on the brink.
The most reputable vendor in this space is Tadiran, and they charge
accordingly.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
On 24 January 2016 at 21:24, Poul-Henning Kamp phk@phk.freebsd.dk wrote:
In message <
CANX10hADbw1u9eJC8_ZgsK94k8Az8vzG4oSe+XnGfWRALi0B0w@mail.gmail.com>
, "Dr. David Kirkby (Kirkby Microwave Ltd)" writes:
Opening the meter up, I see the PCB shows "BT 601". There's no name on the
battery I can see, but the type number of LX 1634. The voltage measured on
my 4.5 digit handheld DVM is 3.03 V. Googling around
My guess is that this is a 3.6V Lithium-Thionyl battery, and if it is
only 3.03V now, you're very likely tethering right on the brink.
The most reputable vendor in this space is Tadiran, and they charge
accordingly.
The post by Glenn (WB4UIV) in the link
https://groups.yahoo.com/neo/groups/hp_agilent_equipment/conversations/topics/48964
does say that it is Lithium-manganese dioxide (Li-MnO2). That information
was apparently taken from the battery manufacturer's web site. So I don't
think it is a Lithium Thionyl Chloride cell, although I'm very tempted to
fit one, as I can get one easy enough and I can't see the extra voltage
would do any harm given the SRAM is 5 V. The SRAM actually gets about 4.8 V
when on mains, so even a fresh Lithium Thionyl Chloride cell, which would
be more than 3.6 V off load, would not be too much for the SRAM. So I think
I am safe for now, but given the cell is at least 11 years old (probably
much older), it is living on borrowed time.
Dave
Lots more info here:
http://www.eevblog.com/forum/blog/eevblog-426-hp-3457a-multimeter-teardown/msg194058/#msg194058
The Panasonic battery I just used measured 3.39 VDC.
Joe Gray
W5JG
On Sun, Jan 24, 2016 at 2:24 PM, Poul-Henning Kamp phk@phk.freebsd.dk wrote:
In message CANX10hADbw1u9eJC8_ZgsK94k8Az8vzG4oSe+XnGfWRALi0B0w@mail.gmail.com
, "Dr. David Kirkby (Kirkby Microwave Ltd)" writes:
Opening the meter up, I see the PCB shows "BT 601". There's no name on the
battery I can see, but the type number of LX 1634. The voltage measured on
my 4.5 digit handheld DVM is 3.03 V. Googling around
My guess is that this is a 3.6V Lithium-Thionyl battery, and if it is
only 3.03V now, you're very likely tethering right on the brink.
The most reputable vendor in this space is Tadiran, and they charge
accordingly.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
volt-nuts mailing list -- volt-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
and follow the instructions there.
In message CANX10hCkNSnxczJx8gccd2-T0J-jOm7yBMncGDviS9iC3yVJjQ@mail.gmail.com
, "Dr. David Kirkby (Kirkby Microwave Ltd)" writes:
The SRAM actually gets about 4.8 V
when on mains, so even a fresh Lithium Thionyl Chloride cell, which would
be more than 3.6 V off load, would not be too much for the SRAM. So I think
I am safe for now, but given the cell is at least 11 years old (probably
much older), it is living on borrowed time.
The one footnote to that is that some SRAMs go into a special "hibernate"
state when VCC drops below a certain threshold. If this SRAM has that,
you want to make sure the threshold is above the battery voltage.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
On 24 January 2016 at 22:16, Poul-Henning Kamp phk@phk.freebsd.dk wrote:
In message <
CANX10hCkNSnxczJx8gccd2-T0J-jOm7yBMncGDviS9iC3yVJjQ@mail.gmail.com>
, "Dr. David Kirkby (Kirkby Microwave Ltd)" writes:
The SRAM actually gets about 4.8 V
when on mains, so even a fresh Lithium Thionyl Chloride cell, which would
be more than 3.6 V off load, would not be too much for the SRAM. So I
think
I am safe for now, but given the cell is at least 11 years old (probably
much older), it is living on borrowed time.
The one footnote to that is that some SRAMs go into a special "hibernate"
state when VCC drops below a certain threshold. If this SRAM has that,
you want to make sure the threshold is above the battery voltage.
Thank you. That is certainly important if that's the case. I can't seem to
find a data sheet on the exact SRAM in my 3457A (Toshiba TC5564PL-15), so
difficult to know.
Dave
On Sun, 24 Jan 2016 19:54:34 +0000
"Dr. David Kirkby (Kirkby Microwave Ltd)" drkirkby@kirkbymicrowave.co.uk wrote:
https://groups.yahoo.com/neo/groups/hp_agilent_equipment/conversations/topics/48964
would suggest the battery was made by Saft and is a Lithium-manganese
dioxide (Li-MnO2). The size appears to be known as 2/3A. One source
suggests a replacment is the Panasonic BR-2/3AE2SP
Mouser's uk site
http://www.mouser.co.uk/
says shipping is restricted, so only available in the USA.
Shipping restricted means that it has to go by ground. Batteries
usually count as "dangerous goods" and thus are not allowed to
be shipped by planes, which rules out most of the delivery services.
At least in Switzerland, mouser shipped batteries fine, they just took
2-3 weeks instead of 2-3 days as they came by post and not with a delivery
service.
Alternatively, you can try to find a local electronics distributor that
has them.
Attila Kinali
--
Reading can seriously damage your ignorance.
-- unknown
In message CANX10hDC=Nq=nv_6pi4mgX53OYtqzCbdvPjGVwrX=T305G+rFA@mail.gmail.com
, "Dr. David Kirkby (Kirkby Microwave Ltd)" writes:
Thank you. That is certainly important if that's the case. I can't seem to
find a data sheet on the exact SRAM in my 3457A (Toshiba TC5564PL-15), so
difficult to know.
This one ?
www.cryptomuseum.com/spy/fs5000/files/TC5564.pdf
That looks like vanilla CMOS RAM, and it has a wide range of
retention VCC, so you should be fine.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
Dave,
Just had a look at my 3457A. The battery is made by Saft, pn. LX1634,
labeled 3.0 volt lithium. Mine measures 3.03 v, same as yours. The
service manual describes the battery only as being part of the power on
reset circuit. It doesn't mention it backing up anything, just acting as
the reference for monitoring the status of the 5v on power up and reset
conditions.
Hope this helps,
Steve
-----Original Message-----
From: Dr. David Kirkby (Kirkby Microwave Ltd)
drkirkby@kirkbymicrowave.co.uk
To: Discussion of precise voltage measurement volt-nuts@febo.com
Cc: hp_agilent_equipment@yahoogroups.com
hp_agilent_equipment@yahoogroups.com
Subject: Re: [volt-nuts] Wanted - UK source of a replacement battery
(type LX 1634) for HP 3457A 6.5 digit multimeter
Date: Sun, 24 Jan 2016 22:08:53 +0000
On 24 January 2016 at 21:24, Poul-Henning Kamp phk@phk.freebsd.dk wrote:
In message <
CANX10hADbw1u9eJC8_ZgsK94k8Az8vzG4oSe+XnGfWRALi0B0w@mail.gmail.com>
, "Dr. David Kirkby (Kirkby Microwave Ltd)" writes:
Opening the meter up, I see the PCB shows "BT 601". There's no name on the
battery I can see, but the type number of LX 1634. The voltage measured on
my 4.5 digit handheld DVM is 3.03 V. Googling around
My guess is that this is a 3.6V Lithium-Thionyl battery, and if it is
only 3.03V now, you're very likely tethering right on the brink.
The most reputable vendor in this space is Tadiran, and they charge
accordingly.
The post by Glenn (WB4UIV) in the link
https://groups.yahoo.com/neo/groups/hp_agilent_equipment/conversations/topics/48964
does say that it is Lithium-manganese dioxide (Li-MnO2). That information
was apparently taken from the battery manufacturer's web site. So I don't
think it is a Lithium Thionyl Chloride cell, although I'm very tempted to
fit one, as I can get one easy enough and I can't see the extra voltage
would do any harm given the SRAM is 5 V. The SRAM actually gets about 4.8 V
when on mains, so even a fresh Lithium Thionyl Chloride cell, which would
be more than 3.6 V off load, would not be too much for the SRAM. So I think
I am safe for now, but given the cell is at least 11 years old (probably
much older), it is living on borrowed time.
Dave
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