Life span of batteries

Discussion in 'Professional Video Production' started by Leo Reyes, Feb 7, 2004.

  1. Leo Reyes

    Leo Reyes Guest

    I have a few batteries Sony InfoLITHIUM for almost three years. They seem to
    lose charge fast while on location. I know that by using the display window
    they go faster, but I do not use the display that much and when I put the
    batteries in the cam, the cam says that I have plenty of hours, but soon my
    cam battery warning signal is flashing?

    L

    --
    www.leoreyes.com
    Public Access TV Producer in San Antonio
    Time Warner Cable
    Channel 20 Saturday 7:30 pm
    Watch Mish-Mash
     
    Leo Reyes, Feb 7, 2004
    #1
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  2. Leo Reyes

    Seymore Guest

    You may want to run one battery down to ~20-30%, then let it fully charge. Do this twice, and see if the battery reports back any
    different. You may also want to post this question on www.SonyCams.com, and see if anyone else has experienced the same situation...

    Seymore...
    Owner of an S85... and luvin' it!
     
    Seymore, Feb 8, 2004
    #2
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  3. You have at least one very weak or dead cell in each of the battery packs.
    Lithium Ion batteries have only so many charge cycles in them. (Don't ask me
    how many. I don't know for sure........ but NiMh batteries have about 500
    full charge cycles I believe)
    That's the problem with this type of battery. Yep.... they are lightweight
    and carry a whole lot of power for that weight, AND they don't have a (so
    called) memory. BUT they must be replaced more often than you would think.
    Such is life.

    Bill F.
     
    Bill Farnsworth, Feb 8, 2004
    #3
  4. Leo Reyes

    Leo Reyes Guest

    Thanks, my feelings too. I will replace them soon thanks
     
    Leo Reyes, Feb 8, 2004
    #4
  5. I've actually had much better experiences with lithium ion than with nickel
    metal. One thing to keep in mind, if a lithium battery gets XX number of
    full cycles, it will get more than 2 x's XX cycles if you only discharge it
    half way. This means that you need to break the old habit of running the
    battery to full discharge if you don't really need to. Makes better sense to
    change out a partially discharged battery at an opportune moment than to
    feel the need to run it into the ground. I also think the lighter weight of
    a lithium battery makes them more durable than the heavier metal or NiCad
    batteries because they are made of the same external materials and suffer
    less from drops and rough handling. I was sending out IDX Nickel Metal NP's
    on DAT machine rentals and they really didn't hold up very well.
     
    Charles Tomaras, Feb 8, 2004
    #5
  6. Leo Reyes

    Toby Guest

    Lithiums have less cycles (usually around 250 I believe) than NiCds and NIMH
    batts and they have a limited life span--of about 3 years, due to chemical
    degradation in the cells over time. This doesn't mean that they go dead on
    the third anniversary, but that you can start to expect a significant drop
    in capacity after those milestones are reached. And as Bill said there is no
    "memory" effect, so deep cycling will not help.

    If I'm wrong please correct me.

    Toby
     
    Toby, Feb 10, 2004
    #6
  7. Leo Reyes

    Toby Guest

    NiMH and NiCd are very prone to succumbing to bad charging and cell
    imbalances. We used to run NP1's and even with a fancy discharger/charger we
    were seeing significant reported capacity loss within a year. We are now
    using Anton Bauer ProPacs with embedded CPUs which report the condition of
    each cell to the charger, which can balance the cells individually. We're at
    51/2 years and about 200 cycles without seeing much of a change.

    BTW the Bauer rep says that capacity begins to decrease after 5 years, but I
    have not experienced that yet.

    Toby
     
    Toby, Feb 10, 2004
    #7
  8. Leo Reyes

    Hughy Guest

    Hi Charles,

    Regarding discharging to only half way - I've had a different experience,
    at least with Canon 941's and Sony NPF-960's.

    I still have two 941's purchased in late 1997. Canon recommend to
    completely discharge their Li Ions after use. I therefore built a
    discharger, by fitting a zener diode and resistor to a broken VL-10Li
    Canon video light. It discharges the 941's down to 6.0 Volts. I have
    used this religiously after every shoot. I usually take all four 941's
    (plus both NPF-960's for our VX) to every shoot and usually come back
    with 1 or 2 batteries almost fully charged.

    The 1997 941's still have about the same capacity as two 941's bought in
    early 2000 (although I haven't ever had the time to carry out proper
    discharge tests). I was expecting battery failures long ago (especially
    the early Canons), but the only battery to have been lost to low capacity
    was a NPF-330 which didn't get the same reverence as the bigger capacity
    Sonys. It lasted only 15 months. The NPF960's are now 3 years old and
    don't yet give low capacity indications.

    I also understand that for the formulation used by Sony, batteries should
    be around 25% charged for best longevity when stored. Although I cannot
    say this from my own experience. I actually fully discharge the 960's
    and haven't had a problem. Even if I only get 750 cycles out of them
    rather than the touted 1000, I'll still consider that good value!

    There's a website around "Cadence" or "Cadow" or somesuch similar company
    name, that make battery dischargers and conditioners etc. Some years ago,
    they were claiming Li Ion's useful life is around 2 years. I'm rather
    pleased to find that my batteries haven't born this out.

    Regards,
    Hughy.
     
    Hughy, Feb 13, 2004
    #8
  9. Leo Reyes

    gothika Guest

    Glad you get long life out of you batts.
    Could you post the values for that diode and resistor also the voltage
    of the lamp?
    I have a commercial batt conditioner but it's designed for larger
    battery packs and I don't think connecting my lith ions up to it would
    be a good idea.
    BTW have you ever had problems with Lith ion giving erratic output?
    I've had a couple of camera over the years that act a bit flakey with
    these batts.(An older Canon and a JVC.)
    It tends to happen during weather extremes. I do keep the cams housed
    or blimped in thermal protection gear but the batts will often read
    dead when used for just a few minutes after a fresh charge. Then when
    the cameras have been turned off for a few minutes then switched back
    on I get a full reading again. This can go on for several times during
    the battery cycle.
    The cameras and the batteries will test out fine when put on the
    bench, just happens in the field with either temp or humidity
    extremes.(I've heard others complain of the same problems.)
    It hasn't happened with our newer gear.
     
    gothika, Feb 14, 2004
    #9
  10. Leo Reyes

    Hughy Guest

    It's a zener diode - 6.0 volts, 1W, but that was what I had just laying
    around. You could also use a 5 Watt or 10 Watt zener which would give
    you a much shorter discharge time. The resistor value is chosen to keep
    the power dissipated at the Zeners rating, when a fully charged battery
    (8.4 volts) is applied. The resistor dissipates the power, there is *no*
    lamp. For a heat sink I mounted the zener on the aluminium base plate of
    the Video light.
    Sounds like a problem with the batteries internal low voltage or
    overcurrent protection mechanism, however I can't be more specific than
    that.
    I've never encountered this problem. I've had lenses that go
    intermittent in the heat of an Australian summer - around 44 C, but
    batteries have performed beyond my expectations (about the only things
    that ever have)!

    Regards,
    Hughy.
     
    Hughy, Feb 25, 2004
    #10
  11. Leo Reyes

    Hughy Guest

    Oops - this should have read: The resistor *AND the zener* dissipates
    the power, there is no lamp.

    Hughy.
     
    Hughy, Feb 26, 2004
    #11
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