Hi It’s those little onboard batteries that I have the experience with. After a while, you are doing well to get a month out of them. Play for a bit longer and they are down to a couple weeks. That’s not a surprising thing, the charging circuit on some of this stuff is often less than perfect. You get a lot of cycles / long life out of a properly handled battery. Abuse the poor thing and not so long a life.
Bob > On Nov 2, 2014, at 4:12 PM, GandalfG8--- via time-nuts <time-nuts@febo.com> > wrote: > > Ah, just found an Engineering Note in my files that again quotes 5uA at > 2.5V but also quotes 100uA at 5.0V, perhaps not too relevant at 3.1V but > that's quite an increase. > > The same document quotes the following specs for the optional onboard > lithium battery... > > Voltage -- 3V > Capacity -- 15mAh > approximately 3 months between charges > Recharge -- approximately 8 hours for a full charge > Lifetime -- 5 Years minimum. > > So I guess an onboard battery conversion might still be a viable option. > > Regards > > Nigel > GM8PZR > > > In a message dated 02/11/2014 21:01:55 GMT Standard Time, kb...@n1k.org > writes: > > Hi > > So then the question becomes - What is the real cutoff voltage? > > Your pair of AA’s will start off at 3.1V, but they will get to 2.5 long > before they are truly dead. Is the RAM gone at 2.5000 or 2.4 or “about 2 > volts > ” …. > > Bob > >> On Nov 2, 2014, at 3:54 PM, GandalfG8--- via time-nuts > <time-nuts@febo.com> wrote: >> >> Hi Bob >> >> The UT+ data sheet from 1998 quotes an external backup supply of 2.5 to >> 5.35V with a drain of 5uA typical at 2.5 Volts. >> >> Regards >> >> Nigel >> GM8PZR >> >> >> In a message dated 02/11/2014 20:41:44 GMT Standard Time, kb...@n1k.org >> writes: >> >> Hi >> >> The numbers quoted earlier (and they sound right) were 20 uA at 2.5V. > That >> would be well under your 100uA. My *guess* is that self discharge / > aging >> on a normal AA is going to limit things faster than a 20 uA drain. >> >> Now, if you have the more normal tiny coin cell involved with 1/10 or >> 1/100 that capacity and much lower self discharge …. >> >> Bob >> >>> On Nov 2, 2014, at 3:17 PM, Hal Murray <hmur...@megapathdsl.net> > wrote: >>> >>>> By the way the z3801 is off most of the year so the drains quite > small. >>> >>> I think that's backwards. The battery is only used when there is no >> power to >>> the GPS module. >>> >>> AAs are roughly 2800 mA hours. There are 8760 hours in a year. > That's >> 319 >>> microamp years. (How's that for a SI unit?) So that's 3 years if > your >> GPS >>> module takes 100 uA. I think that's way high. Anybody measured it? >> There >>> is probably a strong temperature component. >>> >>> >>> -- >>> These are my opinions. I hate spam. >>> >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.