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) <[email protected]> To: Discussion of precise voltage measurement <[email protected]> Cc: [email protected] <[email protected]> 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 <[email protected]> wrote: > -------- > In message < > canx10hadbw1u9ejc8_zgsk94k8az8vzg4ose+xngfwrali0...@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 _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
