HP 50g & NiMH Batteries - Hewlett Packard

This is a discussion on HP 50g & NiMH Batteries - Hewlett Packard ; Im using HP 50g with a local brand of AAA NiMH batteries rated as "1000mAh". When fully charged, if measured with batstat I get 60-65% charge (it is normal to be below 100% at full charge since NiMH batterie are ...

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Thread: HP 50g & NiMH Batteries

  1. HP 50g & NiMH Batteries

    Im using HP 50g with a local brand of AAA NiMH batteries rated as
    "1000mAh".
    When fully charged, if measured with batstat I get 60-65% charge (it
    is normal to be below 100% at full charge since NiMH batterie are 1.2v
    instead of 1.5. With normal, non intensive use, charge quickly drops
    within 1 or 2 days to 35-40%.
    Never used it until "low battery" indication but even then seems like
    battery is going down too fast (probably because of lame batteries,
    just checking to know about other experiences).


  2. Re: HP 50g & NiMH Batteries

    > Never used it until "low battery" indication but even then seems like
    > battery is going down too fast (probably because of lame batteries,
    > just checking to know about other experiences).


    NiMH will drop quickly, then level out for a while, and then drop
    quickly at the end. I use these exclusively in my calculators.
    During weeks of heavy programming, I can drain a set of standard AAs
    in less than 2 weeks. The NiMH ones work great. You will get a low
    battery warning, but you'd better have another set ready to change
    out when it comes as you probably have less than an hour of use left.

    TW



  3. Re: HP 50g & NiMH Batteries

    On Nov 6, 1:08 pm, TW wrote:
    You will get a low
    > battery warning, but you'd better have another set ready to change
    > out when it comes as you probably have less than an hour of use left.
    >
    > TW


    As I have lots of calculators, I actually do not recharge my other set
    until I get low Batt warning as I found that mine do have a tendency
    to self discharge significantly and when my calc is not used too much
    it can be a problem.

    I have also found that batteries completely exhausted for the 49g+/50g
    will work great for quite some time on a 49g/48G

    Arnaud


  4. Re: HP 50g & NiMH Batteries

    > As I have lots of calculators, I actually do not recharge my other set
    > until I get low Batt warning as I found that mine do have a tendency


    Yes. I do as well. Right now there are 3 different 50s on my desk.

    > to self discharge significantly and when my calc is not used too much
    > it can be a problem.


    Good point. I tend to use mine so much I forget just sitting there
    will run them out of juice.

    TW


  5. Re: HP 50g & NiMH Batteries

    TW wrote:
    : > As I have lots of calculators, I actually do not recharge my other set
    : > until I get low Batt warning as I found that mine do have a tendency

    : Yes. I do as well. Right now there are 3 different 50s on my desk.

    : > to self discharge significantly and when my calc is not used too much
    : > it can be a problem.

    : Good point. I tend to use mine so much I forget just sitting there
    : will run them out of juice.

    Have you looked at the Rayovac "hybrid" or Eneloop batteries. They're
    NiMH batteries without the self discharge issue!!

    --




    -------------------
    Keep working millions on welfare depend on you

  6. Re: HP 50g & NiMH Batteries

    On Nov 6, 11:44 am, perstromgren wrote:

    > Use NiMH! Yes, batteries have been better. NiMH is a good example of
    > this.
    >
    > Per.


    Frankly, I've always wondered why we don't have lithium ion
    rechargeable AA/AAA cells available in every retail outlet. That tech
    is used in nearly all laptop computer and mobile phone batteries these
    days, so I can't imagine why it hasn't made its way to the lower end
    items like calculators or flashlights.

    -Dave Britten


  7. Re: HP 50g & NiMH Batteries

    On Nov 5, 11:57 pm, jdol...@gmail.com wrote:
    > Im using HP 50g with a local brand of AAA NiMH batteries rated as
    > "1000mAh".
    > When fully charged, if measured with batstat I get 60-65% charge (it
    > is normal to be below 100% at full charge since NiMH batterie are 1.2v
    > instead of 1.5. With normal, non intensive use, charge quickly drops
    > within 1 or 2 days to 35-40%.
    > Never used it until "low battery" indication but even then seems like
    > battery is going down too fast (probably because of lame batteries,
    > just checking to know about other experiences).



    Try using 2500mAh batteries. I picked up a set of 8 at Frys for $18 or
    so, and have been using them in my cameras quite happily.
    One set will last a day with lots of slash photography.


  8. Re: HP 50g & NiMH Batteries

    cappy2112 wrote in news:1194374260.987262.280520
    @k35g2000prh.googlegroups.com:

    > On Nov 5, 11:57 pm, jdol...@gmail.com wrote:
    >> Im using HP 50g with a local brand of AAA NiMH batteries rated as
    >> "1000mAh".
    >> When fully charged, if measured with batstat I get 60-65% charge (it
    >> is normal to be below 100% at full charge since NiMH batterie are 1.2v
    >> instead of 1.5. With normal, non intensive use, charge quickly drops
    >> within 1 or 2 days to 35-40%.
    >> Never used it until "low battery" indication but even then seems like
    >> battery is going down too fast (probably because of lame batteries,
    >> just checking to know about other experiences).

    >
    >
    > Try using 2500mAh batteries. I picked up a set of 8 at Frys for $18 or
    > so, and have been using them in my cameras quite happily.
    > One set will last a day with lots of slash photography.


    Those would be AAs, not AAAs. 1000mAh isn't bad for a AAA, though I use
    1200mAh cells myself.

    The charging matters a lot. Just because a cell has a rated capacity of
    1000mAh, doesn't mean that your charger is necessarily getting them to
    that point. I like this one, the Maha C9000:

    http://thomasdistributing.com/shop/p...roducts_id=405

    The only downside to it that I've found, is that some of them, mine
    included, can emit a high-pitched squeal, according to some people --
    I've fired too many guns to tell that myself.


    --
    Dave Boyd
    "If we hit that bullseye, the rest of the dominoes will fall
    like a house of cards. Checkmate." -Capt. Zapp Brannigan, D.O.O.P.

  9. Re: HP 50g & NiMH Batteries

    davidbrit2@gmail.com wrote:

    > Frankly, I've always wondered why we don't have lithium ion
    > rechargeable AA/AAA cells available in every retail outlet.


    There's a very simple reason: the Li-Ion system has an output voltage of
    3.6 V per cell. Yes that's three times the nominal voltage of NiMHs and
    more than twice that of a new Alkaline single use battery.

    Now imagine Joe Average putting his brand new Li-Ion rechargeables into
    a device like the HP-50, blowing about 11 Volts into the electronics
    where about 4 V are expected...

    > That tech
    > is used in nearly all laptop computer and mobile phone batteries these
    > days, so I can't imagine why it hasn't made its way to the lower end
    > items like calculators or flashlights.


    All these devices use special sized dedicated batteries that cannot be
    recplaced by standard AA/AAAs. Of course a similar special shaped Li-Ion
    battery pack for the 50G would be possible -- *if* the manufacturer
    offered this option as well as a specially designed battery compartment
    where both three Alkalines/NiMH and the dedicated Li-Ion battery pack
    could be used.

    Dieter


  10. Re: HP 50g & NiMH Batteries

    "Dieter" wrote in message
    news:gcf1j3lk2senqj57pueuodumiqg4im1h2q@4ax.com...
    > There's a very simple reason: the Li-Ion system has an output voltage of
    > 3.6 V per cell. Yes that's three times the nominal voltage of NiMHs and
    > more than twice that of a new Alkaline single use battery.


    This is true, but there's no reason you can't integrate a tiny little
    switching regulator within the cell to drop it down to 1.5V. Apparently this
    is cost prohibitive, though? Plus you lose some energy due to the space taken
    up by the switcher and the losses inherent within, so it probably isn't that
    much better than NiMh by that time.




  11. Re: HP 50g & NiMH Batteries

    On Nov 6, 2:25 pm, Dieter wrote:
    > davidbr...@gmail.com wrote:
    > > Frankly, I've always wondered why we don't have lithium ion
    > > rechargeable AA/AAA cells available in every retail outlet.

    >
    > There's a very simple reason: the Li-Ion system has an output voltage of
    > 3.6 V per cell. Yes that's three times the nominal voltage of NiMHs and
    > more than twice that of a new Alkaline single use battery.
    >
    > Now imagine Joe Average putting his brand new Li-Ion rechargeables into
    > a device like the HP-50, blowing about 11 Volts into the electronics
    > where about 4 V are expected...


    Then that would probably explain it. I'd always had a hunch there must
    be some good reason they aren't available, but with not being an
    electrical/chemical engineer, that specific possibility hadn't crossed
    my mind.

    On a tangentially related note, I've had reasonably good experiences
    with those old Rayovac Renewal rechargeable alkalines in the past for
    low power stuff like calculators or a Gameboy. I'm sure there's
    another perfectly good reason why those aren't around anymore.

    -Dave Britten


  12. Re: HP 50g & NiMH Batteries

    perstromgren wrote:
    >
    > Use NiMH! Yes, batteries have been better. NiMH is a good example of
    > this.


    I have a finicky digital camera that doesn't seem to mind NiMH. They seem
    to be a good replacement to real batteries in many applications.

    - Kurt

  13. Re: HP 50g & NiMH Batteries

    On 6 nov, 23:59, ~kurt wrote:
    > perstromgren wrote:
    >
    > > Use NiMH! Yes, batteries have been better. NiMH is a good example of
    > > this.

    >
    > I have a finicky digital camera that doesn't seem to mind NiMH. They seem
    > to be a good replacement to real batteries in many applications.
    >
    > - Kurt


    NiHM batteries are real batteries too . Rechargeable, but real.

    I think Sanyo Eneloop NiMH batteries plus an ultra fast battery
    charger may be the solution. Eneloop cost is 3X the cost of the
    1000mAh NiMH batteries Im currently using.
    I have no problems with batteries but recharging every week is not
    very attractive, much less if you own a "slow" charger. Not to mention
    having to put in and get out the batteries that often could cause an
    undesired wear of the batteries compartment.


  14. Re: HP 50g & NiMH Batteries

    On Tue, 06 Nov 2007 14:22:52 -0600:

    > there's no reason you can't integrate a tiny little switching regulator
    > within a 3.6v Li-ion cell to drop it down to 1.5V


    Not without an RF noise suppressor, in case the unsuspecting purchaser
    of general-purpose AAA cells might pop them into an AM radio.

    Innumerable design gaffes arise from narrowed attention,
    without considering the entire environment and ecosystem,
    ranging from trivial issues like RF-emitting batteries
    to the health and well-being of the entire Earth.

    -[ ]-

  15. Re: HP 50g & NiMH Batteries

    On Tue, 06 Nov 2007 16:28:06 -0600:

    > On a tangentially related note, I've had reasonably good experiences
    > with those old Rayovac Renewal rechargeable alkalines in the past for
    > low power stuff like calculators or a Gameboy. I'm sure there's
    > another perfectly good reason why those aren't around anymore.


    Corrosively destructive leakage?

    Ray-O-Vac, throughout its long history, has offered to replace devices
    destroyed by leakage of their batteries; perhaps they know
    by long experience (of their customers) that they have to.

    However, if my HP48GX had died from that, there would have been
    no "product of equal value" on the market, and Ray-O-Vac
    would probably have foisted a TI "equivalent" on me.

    Device replacement, malpractice suits, insurance settlements,
    industrial waste cleanup "superfunds,"
    trials of war criminals, and other remedies after the fact,
    do not bring back what's been lost;
    better to avoid destructiveness in the first place,
    arrest the suicidal trashing of the environment,
    and of all the living things and beings who inhabit it,
    by arresting fatigue in the minds of any who would otherwise cause it.

    http://www.youtube.com/watch?v=Xlef9pDMssw
    http://www.geocities.com/odetobobbie...c/lmelinda.htm
    http://www.akh.se/harbel/lyrics/come_away_melinda.htm

    http://www.mum.edu
    http://www.maharishischooliowa.org

    --

  16. Re: HP 50g & NiMH Batteries

    "John H Meyers" wrote in message
    newsp.t1e4tu0vnn735j@miu.edu...
    > On Tue, 06 Nov 2007 14:22:52 -0600:
    >> there's no reason you can't integrate a tiny little switching regulator
    >> within a 3.6v Li-ion cell to drop it down to 1.5V

    > Not without an RF noise suppressor, in case the unsuspecting purchaser
    > of general-purpose AAA cells might pop them into an AM radio.


    That's true, at least for high sensitivity radios (which many $5 Walkman-style
    radios are *not* these days, though) -- you'd probably would want a
    disclaimer about not using them for such purposes.

    Still, by volume I imagine there are relatively few AAA/AA batteries go into
    radios vs. those going into digital devices that wouldn't mind a little bit of
    switching noise at all -- calculators, MP3/CD players, GPS receivers (GPS is
    high enough up in frequency it wouldn't care), etc.

    Just building it all into a metal cell casing will probably provide a
    significant amount of shielding.

    ---Joel



  17. Re: HP 50g & NiMH Batteries

    jdoliva@gmail.com wrote:

    > very attractive, much less if you own a "slow" charger. Not to mention
    > having to put in and get out the batteries that often could cause an
    > undesired wear of the batteries compartment.


    I thought I was the only one who worried about stuff like that....

    - Kurt

  18. Re: HP 50g & NiMH Batteries

    I'm not a heavy user, so I get 36 to 42 days use out of mine. I use them
    until I get an extremely low battery warning during a backup. At that point
    I run it off USB until my reserve batteries are freshly recharged.

    Scott

    wrote in message
    news:1194332245.542878.210240@o3g2000hsb.googlegro ups.com...
    Im using HP 50g with a local brand of AAA NiMH batteries rated as
    "1000mAh".
    When fully charged, if measured with batstat I get 60-65% charge (it
    is normal to be below 100% at full charge since NiMH batterie are 1.2v
    instead of 1.5. With normal, non intensive use, charge quickly drops
    within 1 or 2 days to 35-40%.
    Never used it until "low battery" indication but even then seems like
    battery is going down too fast (probably because of lame batteries,
    just checking to know about other experiences).



  19. Re: HP 50g & NiMH Batteries

    On 06 Nov 2007 Dieter wrote:

    > There's a very simple reason: the Li-Ion system has an output voltage
    > of 3.6 V per cell. Yes that's three times the nominal voltage of NiMHs
    > and more than twice that of a new Alkaline single use battery.
    >
    > Now imagine Joe Average putting his brand new Li-Ion rechargeables
    > into a device like the HP-50, blowing about 11 Volts into the
    > electronics where about 4 V are expected...


    It's worse than that even most come off the charger at over 4.2V,
    although I don't think it would make much difference to the calculator.

    I think another major reason that they are not available is that they
    have a nasty tendency to fail and some times explode if they are not
    handled properly (over discharge, rapid discharge, over charge...).

    They are available in the same sizes as alkalines but I think they are
    mostly used by hobbyists and people with a better understanding of the
    risks than the average guy on the street. Oh and they tend to cost
    between $5 and $10 a cell.

    All in all I am going to stick with NiMh for my calculator.

    --
    Noxonomus

  20. Re: HP 50g & NiMH Batteries

    "Joel Koltner" wrote in
    news:13j3sooto18bqb4@corp.supernews.com:

    > "John H Meyers" wrote in message
    > newsp.t1e4tu0vnn735j@miu.edu...
    >> On Tue, 06 Nov 2007 14:22:52 -0600:
    >>> there's no reason you can't integrate a tiny little switching
    >>> regulator within a 3.6v Li-ion cell to drop it down to 1.5V

    >> Not without an RF noise suppressor, in case the unsuspecting purchaser
    >> of general-purpose AAA cells might pop them into an AM radio.

    >
    > That's true, at least for high sensitivity radios (which many $5
    > Walkman-style radios are *not* these days, though) -- you'd probably
    > would want a disclaimer about not using them for such purposes.
    >
    > Still, by volume I imagine there are relatively few AAA/AA batteries go
    > into radios vs. those going into digital devices that wouldn't mind a
    > little bit of switching noise at all -- calculators, MP3/CD players,
    > GPS receivers (GPS is high enough up in frequency it wouldn't care),
    > etc.


    It is NOT the device it is used in that is the problem, it is those who are
    anywhere near such device and trying to use short wave radio for long
    distance, weak signal, communications.
    Now, I am completely unable to use short wave receivers that I used in the
    60's because of high noise levels across the radio spectrum.
    Modern equipment, with digital noise filters, are the only thing that will
    allow any communications to take place.

    The FCC has been lax in allowing light dimmers and switching supplies on
    the market.
    All we need is batteries that radiate.

    >
    > Just building it all into a metal cell casing will probably provide a
    > significant amount of shielding.


    Not enough, unless the power output is well filtered.









    --
    bz

    please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
    infinite set.

    bz+csm@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

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