jn163051@longs.LANCE.ColoState.Edu (Joel Nevison) (02/11/90)
I would not reccomend using NiCd batteries in the 28s for the following reasons: 1) NiCd batteries won't last as long as a good alkaline battery, NiCd's hold less amp hours per unit volume. NiCd's also tend to self discharge over long periods of time ie. several months. This could produce some nasty surprises when you find your 28s NiCds drained (memory lost). 2) NiCd's forte is the ability to produce high currents for a short time, as opposed to the requirement of a 28s (low currents for a long time). 3) What are you going to power your 28s with while your NiCd's charge? Note - most chargers take eight hours. 4) How often do you need to replace your batteries anyway? Mine have been going for over 14 months now. I'd say go with HP's reccomendations on this one. Joel Nevison "The mole" "I'm underground" jn163051@longs.lance.colostate.edu
adams@hpfelg.HP.COM (John Adams) (02/14/90)
| How often do you need to replace your batteries anyway? Mine have been | going for over 14 months now. | I'd say go with HP's reccomendations on this one. I've had my 28s since July 1988 (19 months) and I have NOT replaced the batteries once! I am not looking forward to it (MEM = 8728.5) either. I also go with HP's recommnedation. John Adams
ge@kunivv1.sci.kun.nl (Ge' Weijers) (02/20/90)
jn163051@longs.LANCE.ColoState.Edu (Joel Nevison) writes: >I would not reccomend using NiCd batteries in the 28s for the following >reasons: >1) NiCd batteries won't last as long as a good alkaline battery, NiCd's >hold less amp hours per unit volume. NiCd's also tend to self discharge >over long periods of time ie. several months. This could produce some >nasty surprises when you find your 28s NiCds drained (memory lost). Does the HP28 run reliably on 3.6V in stead of 4.5V? I wonder... I regularly use a Z88 portable computer I keep fed with NiCd batteries. Normal AA Alkalines are drained after about 20 hours, so this is definitely economically sound. NiCds usually last about a month on standby mode. So if you store the Z88 (or HP28) when you go on a holiday remember to put in a set of normal alkaline batteries. AA (penlight) NiCds are cheap, chargers are common and cheap. This is not true for AAA type chargers. >2) NiCd's forte is the ability to produce high currents for a short time, as >opposed to the requirement of a 28s (low currents for a long time). They're not that bad in low-current applications. Remember to discharge them fully (to 1V) once in a while to prevent the memory-effect from occurring. >3) What are you going to power your 28s with while your NiCd's charge? >Note - most chargers take eight hours. Alkaline batteries, of course, or take 2 sets of NiCds. >4) How often do you need to replace your batteries anyway? Mine have been >going for over 14 months now. You might break even on your investment in perhaps a few years. Add up the cost of a charger and 6 NiCds, and figure out how long it takes before you break even. Is this worth all the hassle? >I'd say go with HP's reccomendations on this one. I couldn't agree more. Ge' Weijers Ge' Weijers Internet/UUCP: ge@cs.kun.nl Faculty of Mathematics and Computer Science, (uunet.uu.net!cs.kun.nl!ge) University of Nijmegen, Toernooiveld 1 6525 ED Nijmegen, the Netherlands tel. +3180612483 (UTC-2)
NSE100@psuvm.psu.edu (Nathan Elsberg) (02/21/90)
I bought my 28s in October 1989 and already had to replace the batteries once.
You might also note that I changed the batteries in less than one minute
(42 seconds to be exact) and I did lose my memory! I don't know maybe I have a
defective calculator. Other than that it's been working terrificly.
Here is a thought, Does the use of the beeper (sound generator) use up an
abnormally high amount of battery life? I suspect so, if anyone out there
has not finished reading through the owners manual you might want to know that
setting flag 51 turns off the sound generator (No more annoying beeps).
If anyone out there thinks that I should contact HP about my battery life and
memory loss, please let me know. I was really upset at first but then I got
over it, plus I don't have a real good case to prove, and what would they do
anyway? Any suggestions please send me E-mail
Nathan Elsberg
Civil Engineering
Penn State University