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9V NiMH batteries, high capacity, any good deals?

Discussion in 'Electronic Design' started by Joerg, Oct 26, 2009.

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  1. Joerg

    Joerg Guest

    Hello All,

    At church we are using Ansmann 9V/250mAh NiMH batteries, lots of them.
    After a few years they are gradually reaching the end of their useful
    life. Looking around I found they now cost about $13 a pop and up.
    Amazon even lists them for a whoppping 20 bucks. Yikes. Maybe because of
    the falling Dollar.

    Is there any other brand from Asia that's a good deal? I'd rather not
    buy from some of the east coast photo dealers anymore because last time
    I experienced, ahem, not so honorable behavior.

    Oh, and to those who develop portable gear: Do _not_ design around 9V
    batteries ...
     
  2. Joerg

    Joerg Guest

    I did some designs with 9V. Grudgingly, and only because the customer
    insisted on it. They sell their own 9V custom batteries and didn't want
    to switch. It's been too long ago but AFAIR we did go to well under 6V.
    Can't do that with NiMH or you'd kill them really fast. One cell
    reversal and it's over.

    Three reasons I do not like 9V at all: First, the energy density is
    lowish. You get 9V/250mAh in about the space of a 1.5V/2600mAh, not a
    good deal. Then, 9V batteries are freaking expensive. >>$10 for NiMH
    whereas a AA cell costs less than two bucks. Same with dry cells. You
    cannot get a decent quality 9V battery under a buck while it is easily
    possible to buy quality AA dry cells for under 30c. Last but not least
    the dreaded contact buttons. I lost count how often either the battery
    contact ripped out or, worse, the pad that connects to the battery tore.
    IMHO this whole 9V block battery concept was ill-conceived from the
    beginning.

    But what can ya do? All the church wireless stuff runs on those 9V
    batteries. But I'll make darn sure that anything we buy for the future
    will use AA.
     
  3. Joerg

    Joerg Guest

    Well, yeah, the green ones from some unnamed manufacturer in China.
    Doesn't even say whether it's a 6-cell or 7-cell design.

    http://cgi.ebay.com/4-x-Ni-MH-300mA...emQQptZLH_DefaultDomain_0?hash=item33566cf34f

    We'd really prefer a brand name. Our experience with no-names was not
    very good over the years. Pastor's mike quitting in the middle of the
    sermon is sort of the worst case. Last Sunday the pulpit mike quit in
    the middle of the 2nd bible reading. *POCK* ... congregation a bit
    startled ... RF carrier gone :-(
     
  4. Joerg

    Joerg Guest


    We don't have enough nerds at church to be sure they don't then just jam
    them into the usual chargers :)
     
  5. Joerg

    Joerg Guest


    I'd say about 50mA continuous, for about 1-1/2 hours per stretch. It's
    all wireless mikes, four Sennheiser EW-series and one older Shure Marcad
    system. Ideally we don't like to change because 1st service, education
    hour and 2nd service run almost back to back. Super caps would never hold.
     
  6. Joerg

    Joerg Guest

    170mAh won't work well for us. Back then, probably about 3-4 years ago,
    I tested various 150mAh, 170mAh, 200mAh and those Ansmann 250mAh
    rechargeables against each other. Essentially by placing them inside a
    wireless mike and let it run until battery voltage cutout. The Ansmann
    clearly won, big time. But AFAICT they are slightly non-standard in
    size, meaning there may be situations where you can't squeeze them in
    without undue force.
     
  7. We used to use Vartas, many years ago. I'm sure they have NIMH now.

    Search, seems to be $7-$10 per battery.

    Cheers
     
  8. Joerg

    Joerg Guest

    We'd need all new charge stations then, plus we need the 9V battery form
    factor.
     
  9. Joerg

    Joerg Guest

    They have a few, between 170mAh and 200mAh, but no 250mAh :-(

    http://www.filmtools.com/varaculnimre.html

    The capacity really made a difference when I tested various brands a few
    years ago.
     
  10. Joerg

    Joerg Guest

    Two of the reviews on Amazon are a bit disconcerting. In the test below
    they didn't quite reach the Ansmann battery performance but we could
    live with the 10% less they delivered:

    http://www.rechargeable-battery-rev...attery-tests/9v-nimh-battery-performance.html

    At least the R&D seems to be in the US:

    http://www.tenergybattery.com/index.php?option=com_frontpage&Itemid=1

    Thanks, Roger, we will give those a shot.
     
  11. _

    _ Guest

    Some time ago i built a 9v source out of an odd-sized cell (2/3 c maybe?)
    and one of those little smps kits. After I re-located the cap to fit
    inside the toroid it and the cell just fit in a 9V space. The cell was
    something like 850 mAh - probably could be double that with today's NiMh
    cells.

    Cost was small, but you'd have to build a special dock for charging it;
    obviously just shoving 9v back through the smps would not work. Contacts
    on the bottom with a cap on 'em perhaps.

    Even though the smps is inefficient, some decent % of 1500 mAh is way
    better.
     
  12. Phil Allison

    Phil Allison Guest

    "_" = a bleeding idiot
    ** Way better than a 250 mAh, *9* volt battery ??

    No fucking way.

    9 time 0.25 = 2.25 watt hrs.

    1.2 times 1.5 = 1.8 watt hrs.



    ...... Phil
     
  13. Nico Coesel

    Nico Coesel Guest

    From my experience: at one of my former employers we found a supplier
    of relatively cheap 9V recharchable batteries after some experimenting
    (that was NiCd). We sold a lot of those to churches. If you are
    willing to experiment a bit you could find batteries that offer the
    best performance.
     
  14. Joerg

    Joerg Guest

    Yesterday I asked our church to order some of the Tenergy batteries that
    Roger had suggested. Around five bucks a pop with shipping, that would
    be very reasonable if they work out. So we'll get four now, test the
    heck out of them, and then if ok replace all the others.
     
  15. JosephKK

    JosephKK Guest

    I have used Tenergy before and was pleased with them. I hope your
    experience is the same.
     
  16. Joerg

    Joerg Guest


    I'll let you guys know when we've had them through the paces. I hope I
    remember ... :)
     
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