Cycling new Ni-Mh batteries...

Discussion in 'Digital Photography' started by Baklava Rodriguez, Nov 8, 2003.

  1. Hello again group,

    I just got some new 2200mAh Ni-Mh rechargables primarily for use in my
    digital camera. I know that such batteries must be cycled ~3-5 times
    before they reach their peak performance. I would like to go ahead
    and do that ASAP so I don't have to deal with reduced-capacity
    batteries when I next go out to take photos. I just need some
    recommendations for quick, safe, and easy ways to discharge my
    batteries(other than putting them in my camera and taking photos of
    nothing until they run out, which is obviously a ridiculous idea) so
    that I can put them through the necessary initial cycles. I've read
    in previous threads that flashlights and similar "low drain" devices
    are not good ideas because they may overdrain the batteries(below 1.0
    V) and reduce their lifespan(I have no expertise in batteries, so I
    have no idea whether or not this is a legitimate concern, I'm just
    stating what I've read). I also read that most portable electronic
    "high-drain" devices will shut off before the batteries' voltage drops
    low enough that overdraining would be a concern. So with all this in
    mind, would it be reasonable to pop my rechargables into a portable TV
    or similar device, turn it on, leave it for long enough for the TV to
    die, and then go recharge them again? Or have I been lead horribly
    astray? If so, please set me straight and give me some suggestions
    for relatively quick, safe, and easy ways to do the necessary 3-5
    cycles.


    Thanks very much in advance,

    Brian
     
    Baklava Rodriguez, Nov 8, 2003
    #1
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  2. Baklava Rodriguez

    Steve B Guest

    Use a torch (flashlight) to drain the batteries.

    However, I measured approximately the mAh rating on my new 2100mAh batteries
    after their first full charge and they were there or thereabouts, so I wouldn't
    worry too much about reduced capacity.
     
    Steve B, Nov 8, 2003
    #2
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  3. I use NiMh battery packs on my hand held radios. I've never bothered
    to cycle them. OTOH, I run my Lithium rechargeables through at least
    two conditioning cycles at the start. I much prefer the Lithiums to
    the NiMh *except* in cold weather.

    I've gotten very good life out of the NiMh batteries. Out of 16
    Lithiums I've had one fail.

    I've lost count of how many NiCads I've had fail, but it's been
    basically every one I've ever purchased. Hence the hand helds now use
    the NiMh.

    Roger Halstead (K8RI EN73 & ARRL Life Member)
    www.rogerhalstead.com
    N833R World's oldest Debonair? (S# CD-2)
     
    Roger Halstead, Nov 8, 2003
    #3
  4. Baklava Rodriguez

    Markus L Guest

    Brian

    Am using a little torch working with a single AA cell. Overdischarge (going
    below 1.0V) is _not_ a risk if you do it with single cells. With groups of
    cells connected in series however this is bad because the weakest cell risks
    to be reversed (voltage going below 0V). A periodic deep discharge is even
    recommended to keep your cells in good shape. See: http://www.buchmann.ca/
    Especially when your cells are used in a device that switches off before the
    cells are fully discharged - most digicams do so - a periodic (every couple
    of months) deep discharge is a good thing to do.

    Markus
     
    Markus L, Nov 8, 2003
    #4
  5. Personally I don't think it is a real issue. The difference is not all
    that much and I doubt if it is worth the difference. Just use them.

    The only time it is normally important is if you are conducting capacity
    test.
     
    Joseph Meehan, Nov 8, 2003
    #5
  6. Baklava Rodriguez

    Dave Cohen Guest

    I am also finding the ratings don't mean much. My non rated Quest perform
    better than my Digital 1800 or Rinpoche 1800 mah units. I've heard the Quest
    are 1300 mah but can't find any claimed rating.
    Dave Cohen
     
    Dave Cohen, Nov 8, 2003
    #6
  7. Baklava Rodriguez

    yep Guest

    I just got some new 2200mAh Ni-Mh rechargables primarily for use in my
    I don't understand why you are so concerned about getting peak
    performance from the start. Even with the first charge, the 2200 will
    give you outstanding performance. Besides, after awhile their
    performance will begin to decline anyways as they don't last forever.

    But if you insist, 'low drain' or not, no rechargeable battery likes
    very deep discharges (the problem is mostly if left that way for a
    long period of time), but removing the batteries for charging before
    the light completely goes out from the flashlight will do the trick
    just fine. A quicker way would be to use them in a motorized device
    such as a CD or tape player.
     
    yep, Nov 8, 2003
    #7
  8. Do *not* do this, unless you are using the flashlight for something and
    stop when you notice the light output dim noticeably.

    If you put the batteries in a flashlight, turn it on, and walk away,
    you'll end up reverse-charging at least one of the cells. There's
    always a weakest cell, and when it reaches zero volts the other 3 are
    still producing power. So current continues flowing, and this current
    starts to charge the weak cell in reverse. It's a good way to destroy
    the cell.

    It's only safe to discharge NiMH or NiCd batteries this way if you have
    a *one cell* flashlight. Otherwise, you need some sort of low-voltage
    cutoff. Most electronic devices have this, but flashlights (and
    resistors) do not.

    Dave
     
    Dave Martindale, Nov 9, 2003
    #8
  9. Baklava Rodriguez

    Browntimdc Guest

    (Dave Martindale) wrote in @mughi.cs.ubc.ca:
    He can get a few one cell flash lights. Maybe hard to find but they do
    exist.

    Tim

    --

    "The strongest human instinct is to impart information,
    and the second strongest is to resist it."

    Kenneth Graham
     
    Browntimdc, Nov 10, 2003
    #9
  10. True. I did say that one-cell flashlights were an exception to the
    rule.

    Dave
     
    Dave Martindale, Nov 10, 2003
    #10
  11. Baklava Rodriguez

    browntimdc Guest

    (Dave Martindale) wrote in @mughi.cs.ubc.ca:
    Sorry, I missed that in your last post. Guess my brain had a stack
    overload.

    Tim
     
    browntimdc, Nov 11, 2003
    #11
  12. Baklava Rodriguez

    jam Guest

    My Maha C-204F charger has a built-in conditioning cycle that
    pre-conditions new NiMH AA sets quite nicely. If I get a new set and
    have the time, I usually pre-condition it as you describe. Otherwise,
    I just use it in the camera, taking care to bring along extra backup
    sets. I've seen some very short runtimes in brand new unconditioned
    AAs. Don't use a flashlight unless you're willing to babysit it very
    closely, as other replies have indicated.
    --
    Jeremy McCreary
    Denver, CO
    www.cliffshade.com/dpfwiw/
    -------------------------------------------

    | Hello again group,
    |
    | I just got some new 2200mAh Ni-Mh rechargables primarily for use in
    my
    | digital camera. I know that such batteries must be cycled ~3-5
    times
    | before they reach their peak performance. I would like to go ahead
    | and do that ASAP so I don't have to deal with reduced-capacity
    | batteries when I next go out to take photos. I just need some
    | recommendations for quick, safe, and easy ways to discharge my
    | batteries(other than putting them in my camera and taking photos of
    | nothing until they run out, which is obviously a ridiculous idea) so
    | that I can put them through the necessary initial cycles. I've read
    | in previous threads that flashlights and similar "low drain" devices
    | are not good ideas because they may overdrain the batteries(below
    1.0
    | V) and reduce their lifespan(I have no expertise in batteries, so I
    | have no idea whether or not this is a legitimate concern, I'm just
    | stating what I've read). I also read that most portable electronic
    | "high-drain" devices will shut off before the batteries' voltage
    drops
    | low enough that overdraining would be a concern. So with all this
    in
    | mind, would it be reasonable to pop my rechargables into a portable
    TV
    | or similar device, turn it on, leave it for long enough for the TV
    to
    | die, and then go recharge them again? Or have I been lead horribly
    | astray? If so, please set me straight and give me some suggestions
    | for relatively quick, safe, and easy ways to do the necessary 3-5
    | cycles.
    |
    |
    | Thanks very much in advance,
    |
    | Brian
     
    jam, Nov 13, 2003
    #12
  13. Baklava Rodriguez

    Guest Guest

    someone I know bought some 'party favor' flashlights at one of those paper
    stores (I think)
    single AA battery. plastic is not thin, fragile. $1 each. I've used one to
    drain old nicads, but hardly have use for the nicads

    (I hardly have use for any battery other than 9v alkaline for smoke alarms).
     
    Guest, Nov 15, 2003
    #13
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