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Thread: Draining batteries.

  1. #1
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    Default Draining batteries.

    There are some who believe in always draining their batteries properly before recharging, and others who don't. This question is directed at the former group. Specifically dSLR users.

    How do you drain your batt? Take pictures until the batt dies? Leave the camera on overnight? Leave the autoplay running until batt flat? Or some other methods?

    i'm using a 10D. Sometimes i leave the auto-play on until the batt is flat, sometimes i just recharge the batts w/o depleteing them. i'm wondering if it's worth 'wearing out' the LCD on a $2.7k camera to save on $27 batteries.

  2. #2
    Member Jer76's Avatar
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    last time regardless of fully charged or not i would still charge them b4 each photoshoot.. now got so many 3rd party bp511 selling so cheaply.. i rather save the LCD

  3. #3

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    What is the reason of draining the batt before re-charging?

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    I think NiMH battery don't have any memory effect. The battery specification always claim that you can recharge the battery any time as long as you don't over charge them.

    I think Lithium Ion batteries are also memory free and need not required to drain completely before recharge.

    NiCd batteries if not properly drain, the battery will lost the power equivalent to the amount of charges that were undrain. This is know to be the memory effect. However, it seems that this effect will only be obvious enough after a few hundred charge cycles.

    Please refer to the web page for the details

    from http://www.repairfaq.org/ELE/F_NiCd_Memory.html

    The real meaning of memory effect comes from precisely repeated charge/ discharges (without overcharging) of sintered-plate[*] nickel-cadmium cells where the cell seems to remember the point of discharge depth. The effect is exceedingly difficult to reproduce, especially in lower ampere-hour cells. In one particular test program -- especially designed to induce memory -- no effect was found after more than 700 precisely-controlled charge/discharge cycles. In the program, spirally- wound one-ampere-hour cells were used. In a follow-up program, 20-ampere-hour aerospace-type cells were used on a similar test regime. Memory effects showed up after a few hundred cycles. [Test program conducted by Pensabene and Gould at GE, I believe.] This kind of memory appears to be related to the "efficiency" of the positive plate. It seems that repeated precise charge cycles affects the ability of the cell's active chemicals to charge fully, after which the positive plate

  5. #5
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    Thanx for e responses, guys.

    Erm... so is there any body out there who does practice draining e batt on your dSLR?

  6. #6
    Member cwaikong's Avatar
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    Hi,

    I am using the Sony Super Quick Charger with Refresh Function. According to the instruction manual, the refresh function will fully discharge a battery and eliminate the "memory effect" caused by charging the battery without first fully discharging it. However, the "refresh" time for 4 x 2100mAh batteries is about 8 hours.

  7. #7

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    I think EastGear has a type of charger (not sure if it is Maha or the other type) that comes with a discharge function to drain the batteries.

    But with current battery technologies, like Ni-MH or Li-Ion, I don't see the need or the advantage to do so. maybe for Ni-Cd.

    Even my handphone, I just charge it even if the battery level is 80%. I don't wait for it to drain and then charge it.

    People claim that will shorten battery life, but I have yet to see a performance drop in my battery life.

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