Tom would agree in general. The charge circuits actually poor. Typically a resistor. But here is the other aspect I have run into. The old memories sucked some real current and would truly drain a LI in 3 months or so. I actually now measure the draw to understand what I am dealing with. Can I get away with your trick or am I stuck with a larger battery and in theory plugging the system in. nimhs float. Just drop the 1/16 C down... Regards Paul.
On Thu, May 3, 2012 at 4:43 PM, Tom Miller <[email protected]> wrote: > I read somewhere that NiMH batteries do not like float charging. You might > do some research on that. > > What I do is disable the charge circuit and install a Tadiran Li 3.6 volt > cell. You keep the diode to isolate the Li cell from the normal 5 volts. > These things will last >20 years and they don't leak. > > Regards, > Tom > > > > ----- Original Message ----- From: "paul swed" <[email protected]> > To: "Discussion of precise time and frequency measurement" < > [email protected]> > Sent: Thursday, May 03, 2012 4:26 PM > Subject: Re: [time-nuts] HP 5334A battery > > > nimh would be the more modern battery that should work in the nicd charge > circuit. > The HP circuits usually were pretty simple actually. > Regards > Paul > > On Thu, May 3, 2012 at 2:11 PM, Scott McGrath <[email protected]> wrote: > > Key here is if battery is ni-cd it implies a charging circuit and using >> alkaline or lithium batteries may explode If charged >> >> On the hp instruments which I have rehabbed from that era most of them >> used nicads with a charger circuit so best advice is replace like with >> like >> >> Sent from my iPhone >> >> On May 3, 2012, at 12:40 PM, Brooke Clarke <[email protected]> wrote: >> >> > Hi: >> > >> > Shelf life is the key spec for memory backup batteries. The worst >> possible type are rechargeable which go dead in a few months. >> > Next best are primary batteries where Alkaline (a few years) is good, >> but newer chemistries like Lithium primary have >> 10 year shelf life. >> > So a computer memory backup battery is the best choice. The largest one >> that fits the space will have much more capacity than the old battery >> because batteries have improved a lot in the past 10 years. >> > http://www.prc68.com/I/batt.**shtml#CC<http://www.prc68.com/I/batt.shtml#CC> >> > >> > Have Fun, >> > >> > Brooke Clarke >> > http://www.PRC68.com >> > http://www.**end2partygovernment.com/**Clarke4Congress.html<http://www.end2partygovernment.com/Clarke4Congress.html> >> > >> > >> > [email protected] wrote: >> >> The best way is to buy a rechargeable cell pack for cordless phones. >> These are typically made with 3 small NiCad so that they don't mind >> trickle >> charging and are already safely packaged in shrink tubing with two leads >> and a connector. When the local Lowe's went out of the phone distribution >> market, they sold many of those small battery packs for $1 or $2 and I got >> a few that I have been using for that purpose. >> >> >> >> Didier KO4BB >> >> >> >> ------Original Message------ >> >> From: [email protected] >> >> Sender: [email protected] >> >> To: Time-Nuts >> >> ReplyTo: [email protected] >> >> ReplyTo: Time-Nuts >> >> Subject: Re: [time-nuts] HP 5334A battery >> >> Sent: May 3, 2012 4:24 AM >> >> >> >>> [email protected] wrote: >> >>> >> >>> My 5334A Service Manual for SERIAL NUMBER PREFIX: 2426A lists the >> following >> >>> battery; >> >>> >> >>> Reference Designation - BT1 >> >>> HP Part Number - 1420-0268 >> >>> Description - Battery 3.6V .065A-HR NI-CD >> >>> Mfr Code - 28480 (which is Hewlett-Packard) >> >>> Mfr Part Number - 1420-0268 >> >>> >> >>> I haven't opened my unit up to make any checks against this data. >>> >> Hope >> >>> this helps. >> >> Sure, thank you. I think that the fastest way to replace it would be to >> >> assemble three ordinary 1.2V cells. >> >> Regards, >> >> Antonio I8IOV >> >> >> >> ______________________________**_________________ >> >> time-nuts mailing list -- [email protected] >> >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/**mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> >> >> and follow the instructions there. >> >> >> >> >> >> Sent from my BlackBerry Wireless thingy while I do other things... >> >> ______________________________**_________________ >> >> time-nuts mailing list -- [email protected] >> >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/**mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> >> >> and follow the instructions there. >> >> >> >> >> > >> > ______________________________**_________________ >> > time-nuts mailing list -- [email protected] >> > To unsubscribe, go to >> https://www.febo.com/cgi-bin/**mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> >> > and follow the instructions there. >> >> ______________________________**_________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/**mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> >> and follow the instructions there. >> >> ______________________________**_________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/** > mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > and follow the instructions there. > > > ______________________________**_________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/** > mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
