Why not use AA cells?

Discussion in 'UK Photography' started by Peter, Jan 18, 2009.

  1. Peter

    Peter Guest

    For 3 years I had a Pentax *ist DL camera. This uses four AA cells, so
    you have a choice

    4 x AA alkaline
    4 x AA lithium (non- or rechargeable)
    2 x CR-V3 lithium (non- or rechargeable)
    4 x AA NIMH (don't "last" long because they are only 1.2V to start
    with)

    I decided to upgrade the resolution (6MP to 10MP) but found that the
    K20 no longer has this option but makes you go for the usual ripoff
    £50 proprietary battery.

    Why do the mfgs do this? I suppose they make lots of money on the
    batteries because everybody has to buy two, plus a charger.

    But it is stupid for the user, because 4 x AA lithiums last a year of
    fairly heavy private usage and cost £10. On a holiday, one already has
    to bring a pile of power packs/chargers...

    I bought the K200 which is their top camera which still has the 4xAA
    option.

    But...... by shaping the moulding, they deliberately blocked the use
    of 2 x CR-V3 which is a shame and I wonder why the hell they did that
    because the batteries in these are exactly the same as 4 x AA lithium,
    but one avoids the use of the somewhat flimsy contacts in the battery
    cover.

    I put the Pentax *ist DL on Ebay...
     
    Peter, Jan 18, 2009
    #1
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  2. Peter

    Woody Guest



    For a start two things - weight and life. The proprietry battery is
    probably Li-Ion which is much smaller and light than 4xAA, and as you
    say starts at a higher voltage - usually 7.2V. Ths plate voltage under
    use is also more constant on a Li-Ion and they can be rapidly charged.
    You also don't need to pay £50 for the spare battery - I paid about £10
    for the unit for my D70s and it is identical to the original minus the
    Nikon logo and lasts every bit as long.

    The third - and probably most surprising - is that even someone buying a
    dSLR is not necessarily battery savvy and will probably use Duracells
    thinking they are as good as Ni-MH and wonder why they don't last five
    minutes. Lithium AA's are also not that widely available. You and I know
    what they look like and probably where to buy them (and at the right
    price) but that is not so world wide - and dSLRs are made for a world
    market. Same comments re supply on CR-V3.

    Finally there is a strong move in the camera industry - like the phone
    industry - to use 3.6V so that it can be charged from a USB outlet or
    similar interface. It also means that the manufacturer can use
    technology within the camera that is made to run at lower voltages -
    like that in mobile phones - and can thus save on manufacturing costs.
     
    Woody, Jan 18, 2009
    #2
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  3. Peter

    Peter Guest

    One thing which concerns me on the specialised lithium cells is
    whether anybody "chips" them, like they do with inkjet cartridges. I
    am an electronics design engineer and there is a number of chips on
    the market designed for "infolithium" type cells which have
    anti-counterfeit features. I don't suppose many camera mfgs use these
    right now otherwise Ebay would not be full of £10 versions of the £50
    cells but they might do one day. Didn't Sony try this stunt once? I
    won't touch Sony or Nikon with a bargepole, for the duff-battery scam
    a few years ago and for lousy customer service, respectively.
    I remain curious as to why Pentax blocked the use of the CR-V3 in the
    K200 when they allowed it in earlier "4xAA" models. There seems to be
    no reason for this.
    That is odd too, since upconverting from the +5V USB supply to
    whatever you need, costs only pennies. Most modern digital electronics
    run at +3.3V anyway, but lithium technology gets you 3.6V or so and if
    you need more than one cell then you get 7.2V with 2 in series, and
    one cannot put them in parallel without getting into complications. A
    battery which is 3.6V would have to be a single cell, I think.
     
    Peter, Jan 18, 2009
    #3
  4. I bought one of these:
    http://batterylogic.co.uk/uniross-magic-charger.asp



    --
    Alan

    ( If replying by mail, please note that all "sardines" are canned.
    However, unless this a very old message, a "tuna" will swim right
    through. )
     
    Alan Clifford, Jan 18, 2009
    #4
  5. Peter

    Peter Guest

    Peter, Jan 18, 2009
    #5
  6. Peter

    Bruce Guest


    I'm not especially a Sony fan, but the InfoLithium battery in my Sony
    digital camera provides an excellent, reliable estimate of the life
    remaining in terms of minutes. It is uncannily accurate.

    I am not surprised that, having developed this technology, Sony would
    want to hang on to it, because it may well be a factor in many people's
    purchasing decisions.

    I also have a Panasonic digital camera. It also provides an estimate of
    time remaining, but it often misleads and therefore cannot be relied on.
     
    Bruce, Jan 18, 2009
    #6
  7. The blurb does mention some Sony batteries that is won't charge so it is
    probably those. But it does my 'phone, point and shoot, slr and I
    soldered a bigger plug onto the lead to charge my gps tracker. It does
    the AAs for my flash as well.

    I'd have to keep getting up throughout the night to change batteries if I
    wanted to charge everything in it in one night but it is a useful item
    when travelling.

    Oh yes, also the AAAs for my toothbrush.

    --
    Alan

    ( If replying by mail, please note that all "sardines" are canned.
    However, unless this a very old message, a "tuna" will swim right
    through. )
     
    Alan Clifford, Jan 18, 2009
    #7
  8. Peter

    OG Guest

    Not my experience if you buy the new low self discharge cells (Eneloop,
    Hybrio etc). These may appear to have a lower overall capacity (2100mAh
    typical) but they have less drop in their supply voltage than standard NiMh
    cells, so you'll get more actual life out of the cells before the camera
    complains.

    I expect to get about 600+ shots from a fully charged set.
     
    OG, Jan 19, 2009
    #8
  9. Duracell make NiMH batteries in AA size, I have some.
    Regards Mike.
     
    Mike Cawood, HND BIT, Jan 22, 2009
    #9
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