Re: NiMH cell voltage

Discussion in 'Digital Photography' started by ransley, Sep 15, 2008.

  1. ransley

    ransley Guest

    On Sep 14, 9:48 am, Daniel Prince <> wrote:
    > Sometime ago, I bought a used camera on eBay.  It uses two AA cells.
    > I noticed that I was not getting very good battery life with Kodak
    > 2.1 ah pre-charged cells.  
    >
    > Yesterday when the camera said that it needed new batteries, I
    > checked the voltage of the cells.  One was 1.288 volts and the other
    > was 1.292 volts.
    >
    > These voltages seem much too high for "dead" batteries to me.  I
    > checked the menus on the camera and the manual and did not find a
    > setting for battery type.
    >
    > Is this camera defective and rejecting batteries at too high a
    > voltage?  Thank you in advance for all replies.
    > --
    > Whenever I hear or think of the song "Great green gobs of greasy
    > grimey gopher guts" I imagine my cat saying; "That sounds REALLY,
    > REALLY good.  I'll have some of that!"


    My sanyo Eneloops are fully charged at 1.5v and wont run my camera at
    1.29v My Sony came with Nimh, Get new batteries or charger.
    ransley, Sep 15, 2008
    #1
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  2. ransley

    nospam Guest

    In article
    <>,
    ransley <> wrote:

    > My sanyo Eneloops are fully charged at 1.5v and wont run my camera at
    > 1.29v My Sony came with Nimh, Get new batteries or charger.


    nimh batteries do not put out 1.5v.
    nospam, Sep 15, 2008
    #2
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  3. ransley

    ransley Guest

    On Sep 14, 9:26 pm, nospam <> wrote:
    > In article
    > <>,
    >
    > ransley <> wrote:
    > > My sanyo Eneloops are fully charged at 1.5v and wont run my camera at
    > > 1.29v My Sony came with Nimh, Get new batteries or charger.

    >
    > nimh batteries do not put out 1.5v.


    Right, go buy a new V meter and some Eneloops and a good charger. I
    just got done charging 3 sets. And I supose you think a cars lead acid
    battery is charged at 12v. Nimh-Nicad are basicly dead at 1.2v
    ransley, Sep 15, 2008
    #3
  4. ransley

    ASAAR Guest

    On Sun, 14 Sep 2008 20:32:27 -0700 (PDT), ransley wrote:

    >> ransley <> wrote:
    >>> My sanyo Eneloops are fully charged at 1.5v and wont run my camera at
    >>> 1.29v My Sony came with Nimh, Get new batteries or charger.

    >>
    >> nimh batteries do not put out 1.5v.

    >
    > Right, go buy a new V meter and some Eneloops and a good charger. I
    > just got done charging 3 sets. And I supose you think a cars lead acid
    > battery is charged at 12v. Nimh-Nicad are basicly dead at 1.2v


    Totally wrong, as a quick glance at NiMH manufacturer's data
    sheets will show. Eneloops have the same voltage characteristics as
    standard NiMH batteries. This is from one of Energizer's old NiMH
    AA engineering data sheets :

    > Designation: ANSI-1.2H2
    > Battery Voltage: 1.2 Volts
    > Average Capacity: 1850 mAh (to 1.0 volts)
    > (Based on 370 mA (0.2C) discharge rate)


    and this is from Duracell's Tech Bulletin :

    > 5.1 General Characteristics
    > The discharge characteristics of the nickel-metal
    > hydride cell are very similar to those of the nickelcadmium
    > cell. The charged open circuit voltage of both
    > systems ranges from 1.25 to 1.35 volts per cell. On
    > discharge, the nominal voltage is 1.2 volts per cell and
    > the typical end voltage is 1.0 volt per cell.



    http://www.duracell.com/oem/rechargeable/Nickel/nickel_metal_tech.asp
    ASAAR, Sep 15, 2008
    #4
  5. ransley

    nospam Guest

    In article
    <>,
    ransley <> wrote:

    > > > My sanyo Eneloops are fully charged at 1.5v and wont run my camera at
    > > > 1.29v My Sony came with Nimh, Get new batteries or charger.

    > >
    > > nimh batteries do not put out 1.5v.

    >
    > Right, go buy a new V meter and some Eneloops and a good charger. I
    > just got done charging 3 sets. And I supose you think a cars lead acid
    > battery is charged at 12v. Nimh-Nicad are basicly dead at 1.2v


    there's nothing wrong with my meter or charger. perhaps it is you who
    needs a replacement or at least learn how to use what you have.
    furthermore, go read up on the chemistry of nimh batteries. the
    nominal voltage of nimh/nicad batteries are 1.2v.
    nospam, Sep 15, 2008
    #5
  6. ransley

    ransley Guest

    On Sep 14, 11:21 pm, ASAAR <> wrote:
    > On Sun, 14 Sep 2008 20:32:27 -0700 (PDT), ransley wrote:
    > >> ransley <> wrote:
    > >>> My sanyo Eneloops are fully charged at 1.5v and wont run my camera at
    > >>> 1.29v My Sony came with Nimh, Get new batteries or charger.

    >
    > >> nimh batteries do not put out 1.5v.

    >
    > > Right, go buy a new V meter and some Eneloops and a good charger. I
    > > just got done charging 3 sets. And I supose you think a cars lead acid
    > > battery is charged at 12v. Nimh-Nicad are basicly dead at 1.2v

    >
    >   Totally wrong, as a quick glance at NiMH manufacturer's data
    > sheets will show.  Eneloops have the same voltage characteristics as
    > standard NiMH batteries.  This is from one of Energizer's old NiMH
    > AA engineering data sheets :
    >
    > > Designation: ANSI-1.2H2
    > > Battery Voltage: 1.2 Volts
    > > Average Capacity: 1850 mAh (to 1.0 volts)
    > > (Based on 370 mA (0.2C) discharge rate)

    >
    >  and this is from Duracell's Tech Bulletin :
    >
    > > 5.1 General Characteristics
    > > The discharge characteristics of the nickel-metal
    > > hydride cell are very similar to those of the nickelcadmium
    > > cell. The charged open circuit voltage of both
    > > systems ranges from 1.25 to 1.35 volts per cell. On
    > > discharge, the nominal voltage is 1.2 volts per cell and
    > > the typical end voltage is 1.0 volt per cell.

    >
    > http://www.duracell.com/oem/rechargeable/Nickel/nickel_metal_tech.asp


    I just read a few spec sheets showing 1.35-1.4 being a stablised full
    charge of Nimh, My sony charger peaked it out at 1.5 and today on 2
    different meter I am showing 1.38-1.4v on Eneloop cells, at 1.2v they
    are basicly discharged and wont even power up my camera at 1.29v,
    These are nearly the same voltage patterns as I have seen from Nicads.
    Eneloops do take 1.5v to peak on my 2 sony Nimh chargers.
    ransley, Sep 15, 2008
    #6
  7. ransley

    ASAAR Guest

    On Mon, 15 Sep 2008 05:54:56 -0700 (PDT), ransley wrote:

    >>> 5.1 General Characteristics
    >>> The discharge characteristics of the nickel-metal
    >>> hydride cell are very similar to those of the nickelcadmium
    >>> cell. The charged open circuit voltage of both
    >>> systems ranges from 1.25 to 1.35 volts per cell. On
    >>> discharge, the nominal voltage is 1.2 volts per cell and
    >>> the typical end voltage is 1.0 volt per cell.

    >>
    >> http://www.duracell.com/oem/rechargeable/Nickel/nickel_metal_tech.asp

    >
    > I just read a few spec sheets showing 1.35-1.4 being a stablised full
    > charge of Nimh, My sony charger peaked it out at 1.5 and today on 2
    > different meter I am showing 1.38-1.4v on Eneloop cells, at 1.2v they
    > are basicly discharged and wont even power up my camera at 1.29v,
    > These are nearly the same voltage patterns as I have seen from Nicads.
    > Eneloops do take 1.5v to peak on my 2 sony Nimh chargers.


    If that's what you've found, then it only shows that your meters
    are either inaccurate or need calibration. All of mine, from cheap
    Radio Shack to much better Fluke digitals show what Duracell's tech.
    bulletin claims. I've also used chargers that had the ability to
    discharge AA cells, automatically switching to charge mode after
    reaching (and displaying) the 1.0v discharged cell point. I'm sure
    that Duracell and Energizer use better meters than I use, and keep
    them well calibrated. I will grant you that most of the charge is
    delivered at or above 1.2 volts, but when they reach 1.2 volts can
    still power equipment for minutes to hours until they reach 1.1
    volts, depending on the current load (and they're not completely
    dead at that point, as you can see if you put them in a low power
    LED flashlight).

    The minimum voltage required to operate cameras also varies, and
    some will shut down well before others. I haven't personally
    measured this with cameras, but have done so for digital radios that
    use 4 AA cells. What you want is a radio that shuts down at a
    voltage of about 4.0 volts, as this point would be reached when the
    first cell to poop out is almost completely discharged, protecting
    it from being reverse charged by the remaining three cells. I have
    several old but very nice Sony radios that were obviously designed
    for use with alkaline batteries. They keep working even when the
    voltage drops to about 3.0 volts. This allows them to be more
    efficient, getting more life out of alkaline batteries. But it also
    makes them horrible for use with NiCd or NiMH batteries, as it
    easily reverse charges some cells, ruining some of them before
    they've reached 2 or 3 charge cycles.

    I'm not sure how your Sony chargers work, but while being charged
    it wouldn't be odd for the cells to show a 1.4 to 1.5v potential,
    but the open circuit voltage will drop, and if placed under load
    should drop to below 1.3 volts (as measured by an accurate meter)
    almost instantly under the moderate load of a camera or bulb or
    taking slightly longer under lighter loads.
    ASAAR, Sep 15, 2008
    #7
  8. ransley

    Steve B Guest

    "nospam" <> wrote in message
    news:150920080129532642%...
    > In article
    > <>,
    > ransley <> wrote:
    >
    >> > > My sanyo Eneloops are fully charged at 1.5v and wont run my camera at
    >> > > 1.29v My Sony came with Nimh, Get new batteries or charger.
    >> >
    >> > nimh batteries do not put out 1.5v.

    >>
    >> Right, go buy a new V meter and some Eneloops and a good charger. I
    >> just got done charging 3 sets. And I supose you think a cars lead acid
    >> battery is charged at 12v. Nimh-Nicad are basicly dead at 1.2v

    >
    > there's nothing wrong with my meter or charger. perhaps it is you who
    > needs a replacement or at least learn how to use what you have.
    > furthermore, go read up on the chemistry of nimh batteries. the
    > nominal voltage of nimh/nicad batteries are 1.2v.


    From my own (accurate) readings on many NiMh cells over the years, 1.29v
    usually means there's plenty of life left in a cell. A voltage reading
    unfortunately gives zero information as to the health of the cell, i.e. it's
    internal resistance, so if it doesn't work properly in a camera at this
    off-load voltage then be very suspicious of it's state of health.

    NiMh voltage plateaus in use at around 1.20 - 1.24v for most makes, low
    self-discharge ones may be a little higher, but it plummets rapidly in use
    once it has fallen to 1.15v. This makes 1.15v - 1.19v a good region for a
    camera to shut down, my Pentax K100D shuts down at 4.76v, i.e. 1.19v per
    cell. It would give better battery life at 1.15v but there's always the
    risk the camera would die during a flash recharge or autofocus current surge
    which would pull the battery voltage below the threshold for a second or
    two, probably making the camera try to shutdown.
    Steve B, Sep 15, 2008
    #8
  9. ransley

    ransley Guest

    On Sep 15, 12:22 pm, ASAAR <> wrote:
    > On Mon, 15 Sep 2008 05:54:56 -0700 (PDT), ransley wrote:
    > >>> 5.1 General Characteristics
    > >>> The discharge characteristics of the nickel-metal
    > >>> hydride cell are very similar to those of the nickelcadmium
    > >>> cell. The charged open circuit voltage of both
    > >>> systems ranges from 1.25 to 1.35 volts per cell. On
    > >>> discharge, the nominal voltage is 1.2 volts per cell and
    > >>> the typical end voltage is 1.0 volt per cell.

    >
    > >>http://www.duracell.com/oem/rechargeable/Nickel/nickel_metal_tech.asp

    >
    > > I just read a few spec sheets showing 1.35-1.4 being a stablised full
    > > charge of Nimh, My sony charger peaked it out at 1.5 and today on 2
    > > different meter I am showing 1.38-1.4v on Eneloop cells, at 1.2v they
    > > are basicly discharged and wont even power up my camera at 1.29v,
    > > These are nearly the same voltage patterns as I have seen from Nicads.
    > > Eneloops do take 1.5v to peak on my 2 sony Nimh chargers.

    >
    >   If that's what you've found, then it only shows that your meters
    > are either inaccurate or need calibration.  All of mine, from cheap
    > Radio Shack to much better Fluke digitals show what Duracell's tech.
    > bulletin claims.  I've also used chargers that had the ability to
    > discharge AA cells, automatically switching to charge mode after
    > reaching (and displaying) the 1.0v discharged cell point.  I'm sure
    > that Duracell and Energizer use better meters than I use, and keep
    > them well calibrated.  I will grant you that most of the charge is
    > delivered at or above 1.2 volts, but when they reach 1.2 volts can
    > still power equipment for minutes to hours until they reach 1.1
    > volts, depending on the current load (and they're not completely
    > dead at that point, as you can see if you put them in a low power
    > LED flashlight).
    >
    >   The minimum voltage required to operate cameras also varies, and
    > some will shut down well before others.  I haven't personally
    > measured this with cameras, but have done so for digital radios that
    > use 4 AA cells.  What you want is a radio that shuts down at a
    > voltage of about 4.0 volts, as this point would be reached when the
    > first cell to poop out is almost completely discharged, protecting
    > it from being reverse charged by the remaining three cells.  I have
    > several old but very nice Sony radios that were obviously designed
    > for use with alkaline batteries.  They keep working even when the
    > voltage drops to about 3.0 volts.  This allows them to be more
    > efficient, getting more life out of alkaline batteries.  But it also
    > makes them horrible for use with NiCd or NiMH batteries, as it
    > easily reverse charges some cells, ruining some of them before
    > they've reached 2 or 3 charge cycles.
    >
    >   I'm not sure how your Sony chargers work, but while being charged
    > it wouldn't be odd for the cells to show a 1.4 to 1.5v potential,
    > but the open circuit voltage will drop, and if placed under load
    > should drop to below 1.3 volts (as measured by an accurate meter)
    > almost instantly under the moderate load of a camera or bulb or
    > taking slightly longer under lighter loads.- Hide quoted text -
    >
    > - Show quoted text -


    Well I better go see if my meter is bad and get a new one, but my car
    and car battery charger are also about the same when I double check
    voltages. I have felt heat from the cells so maybe these sony chargers
    are not very good. They are the standard charger that comes with their
    cameras and 2 sony aa Nimh cells. I just charged another pair and
    after a few hours 1.4v is what I read.
    ransley, Sep 15, 2008
    #9
  10. ransley

    ASAAR Guest

    On Mon, 15 Sep 2008 15:02:07 -0700 (PDT), ransley wrote:

    > Well I better go see if my meter is bad and get a new one, but my car
    > and car battery charger are also about the same when I double check
    > voltages. I have felt heat from the cells so maybe these sony chargers
    > are not very good. They are the standard charger that comes with their
    > cameras and 2 sony aa Nimh cells. I just charged another pair and
    > after a few hours 1.4v is what I read.


    If your NiMH cells seem to be getting a decent charge I wouldn't
    fret too much about the Sony chargers*. Most chargers heat
    batteries, some more than others, but usually not much heat is
    produced until the cells approach full charge. I assume that you're
    using a digital meter but if it's analog, their accuracy is a
    certain percentage of the full scale voltage, which can produce
    large inaccuracies if you're not using the scale that gets the
    largest needle excursion.

    * If the Sony chargers can only charge cells in pairs, you might
    want to consider getting one that charges cells independently and
    has either an LED or LCD display for each cell, showing its charge
    progress. You can spend more for better chargers that show the
    actual voltages (and other information) for each of the cells, but
    they won't necessarily do a better job of charging than the more
    inexpensive ones will.
    ASAAR, Sep 15, 2008
    #10
  11. ransley

    ransley Guest

    On Sep 16, 2:47 am, Ron Hunter <> wrote:
    > ransley wrote:
    > > On Sep 14, 11:21 pm, ASAAR <> wrote:
    > >> On Sun, 14 Sep 2008 20:32:27 -0700 (PDT), ransley wrote:
    > >>>> ransley <> wrote:
    > >>>>> My sanyo Eneloops are fully charged at 1.5v and wont run my camera at
    > >>>>> 1.29v My Sony came with Nimh, Get new batteries or charger.
    > >>>> nimh batteries do not put out 1.5v.
    > >>> Right, go buy a new V meter and some Eneloops and a good charger. I
    > >>> just got done charging 3 sets. And I supose you think a cars lead acid
    > >>> battery is charged at 12v. Nimh-Nicad are basicly dead at 1.2v
    > >>   Totally wrong, as a quick glance at NiMH manufacturer's data
    > >> sheets will show.  Eneloops have the same voltage characteristics as
    > >> standard NiMH batteries.  This is from one of Energizer's old NiMH
    > >> AA engineering data sheets :

    >
    > >>> Designation: ANSI-1.2H2
    > >>> Battery Voltage: 1.2 Volts
    > >>> Average Capacity: 1850 mAh (to 1.0 volts)
    > >>> (Based on 370 mA (0.2C) discharge rate)
    > >>  and this is from Duracell's Tech Bulletin :

    >
    > >>> 5.1 General Characteristics
    > >>> The discharge characteristics of the nickel-metal
    > >>> hydride cell are very similar to those of the nickelcadmium
    > >>> cell. The charged open circuit voltage of both
    > >>> systems ranges from 1.25 to 1.35 volts per cell. On
    > >>> discharge, the nominal voltage is 1.2 volts per cell and
    > >>> the typical end voltage is 1.0 volt per cell.
    > >>http://www.duracell.com/oem/rechargeable/Nickel/nickel_metal_tech.asp

    >
    > > I just read a few spec sheets showing 1.35-1.4 being a stablised full
    > > charge of Nimh, My sony charger peaked it out at 1.5 and today on 2
    > > different meter I am showing 1.38-1.4v on Eneloop cells, at 1.2v they
    > > are basicly discharged and wont even power up my camera at 1.29v,
    > > These are nearly the same voltage patterns as I have seen from Nicads.
    > > Eneloops do take 1.5v to peak on my 2 sony Nimh chargers.

    >
    > I have never seen a battery that will put out more voltage than the
    > chemical action allows, and for NiMH, that is about 1.24-1.3 volts.  The
    > 1.3 volt reading is a no-load condition on a battery fresh out of the
    > charger, and should be considered 'transient'.  A discharged NiMH would
    > measure about 1.0 to 1.1 volt.  I suspect you have a meter inaccuracy,
    > and please send the URL for those 1.39-1.4 voltage numbers.- Hide quoted text -
    >
    > - Show quoted text -


    In using 2 digital meters that in other usage has been shown accurate.
    Today after taking a few shots even with flash I am showing 1.38v, Its
    time to verify my meter or get a new one. What does everyone else show
    for V on a fully charged NiMh
    ransley, Sep 16, 2008
    #11
  12. ransley

    ransley Guest

    On Sep 16, 2:47 am, Ron Hunter <> wrote:
    > ransley wrote:
    > > On Sep 14, 11:21 pm, ASAAR <> wrote:
    > >> On Sun, 14 Sep 2008 20:32:27 -0700 (PDT), ransley wrote:
    > >>>> ransley <> wrote:
    > >>>>> My sanyo Eneloops are fully charged at 1.5v and wont run my camera at
    > >>>>> 1.29v My Sony came with Nimh, Get new batteries or charger.
    > >>>> nimh batteries do not put out 1.5v.
    > >>> Right, go buy a new V meter and some Eneloops and a good charger. I
    > >>> just got done charging 3 sets. And I supose you think a cars lead acid
    > >>> battery is charged at 12v. Nimh-Nicad are basicly dead at 1.2v
    > >>   Totally wrong, as a quick glance at NiMH manufacturer's data
    > >> sheets will show.  Eneloops have the same voltage characteristics as
    > >> standard NiMH batteries.  This is from one of Energizer's old NiMH
    > >> AA engineering data sheets :

    >
    > >>> Designation: ANSI-1.2H2
    > >>> Battery Voltage: 1.2 Volts
    > >>> Average Capacity: 1850 mAh (to 1.0 volts)
    > >>> (Based on 370 mA (0.2C) discharge rate)
    > >>  and this is from Duracell's Tech Bulletin :

    >
    > >>> 5.1 General Characteristics
    > >>> The discharge characteristics of the nickel-metal
    > >>> hydride cell are very similar to those of the nickelcadmium
    > >>> cell. The charged open circuit voltage of both
    > >>> systems ranges from 1.25 to 1.35 volts per cell. On
    > >>> discharge, the nominal voltage is 1.2 volts per cell and
    > >>> the typical end voltage is 1.0 volt per cell.
    > >>http://www.duracell.com/oem/rechargeable/Nickel/nickel_metal_tech.asp

    >
    > > I just read a few spec sheets showing 1.35-1.4 being a stablised full
    > > charge of Nimh, My sony charger peaked it out at 1.5 and today on 2
    > > different meter I am showing 1.38-1.4v on Eneloop cells, at 1.2v they
    > > are basicly discharged and wont even power up my camera at 1.29v,
    > > These are nearly the same voltage patterns as I have seen from Nicads.
    > > Eneloops do take 1.5v to peak on my 2 sony Nimh chargers.

    >
    > I have never seen a battery that will put out more voltage than the
    > chemical action allows, and for NiMH, that is about 1.24-1.3 volts.  The
    > 1.3 volt reading is a no-load condition on a battery fresh out of the
    > charger, and should be considered 'transient'.  A discharged NiMH would
    > measure about 1.0 to 1.1 volt.  I suspect you have a meter inaccuracy,
    > and please send the URL for those 1.39-1.4 voltage numbers.- Hide quoted text -
    >
    > - Show quoted text -


    1.35 - 1.4v a cell unloaded is most easily found at Wikipedia, I
    peaked out of the sony charger at 1.5v, within a day it showed 1.4.
    After a few shots 1.38. So what I just saw at Wikipedia shows I am
    inline with specs. My Nicads are about the same in full v charge even
    on my manualy done charging, peaking by just reading voltage drop, for
    my RC toys. An auto lead acid battery is nearly discharged at 12v, so
    are AA rechargeables.
    ransley, Sep 16, 2008
    #12
  13. ransley

    ransley Guest

    On Sep 16, 7:13 am, ransley <> wrote:
    > On Sep 16, 2:47 am, Ron Hunter <> wrote:
    >
    >
    >
    >
    >
    > > ransley wrote:
    > > > On Sep 14, 11:21 pm, ASAAR <> wrote:
    > > >> On Sun, 14 Sep 2008 20:32:27 -0700 (PDT), ransley wrote:
    > > >>>> ransley <> wrote:
    > > >>>>> My sanyo Eneloops are fully charged at 1.5v and wont run my camera at
    > > >>>>> 1.29v My Sony came with Nimh, Get new batteries or charger.
    > > >>>> nimh batteries do not put out 1.5v.
    > > >>> Right, go buy a new V meter and some Eneloops and a good charger. I
    > > >>> just got done charging 3 sets. And I supose you think a cars lead acid
    > > >>> battery is charged at 12v. Nimh-Nicad are basicly dead at 1.2v
    > > >>   Totally wrong, as a quick glance at NiMH manufacturer's data
    > > >> sheets will show.  Eneloops have the same voltage characteristics as
    > > >> standard NiMH batteries.  This is from one of Energizer's old NiMH
    > > >> AA engineering data sheets :

    >
    > > >>> Designation: ANSI-1.2H2
    > > >>> Battery Voltage: 1.2 Volts
    > > >>> Average Capacity: 1850 mAh (to 1.0 volts)
    > > >>> (Based on 370 mA (0.2C) discharge rate)
    > > >>  and this is from Duracell's Tech Bulletin :

    >
    > > >>> 5.1 General Characteristics
    > > >>> The discharge characteristics of the nickel-metal
    > > >>> hydride cell are very similar to those of the nickelcadmium
    > > >>> cell. The charged open circuit voltage of both
    > > >>> systems ranges from 1.25 to 1.35 volts per cell. On
    > > >>> discharge, the nominal voltage is 1.2 volts per cell and
    > > >>> the typical end voltage is 1.0 volt per cell.
    > > >>http://www.duracell.com/oem/rechargeable/Nickel/nickel_metal_tech.asp

    >
    > > > I just read a few spec sheets showing 1.35-1.4 being a stablised full
    > > > charge of Nimh, My sony charger peaked it out at 1.5 and today on 2
    > > > different meter I am showing 1.38-1.4v on Eneloop cells, at 1.2v they
    > > > are basicly discharged and wont even power up my camera at 1.29v,
    > > > These are nearly the same voltage patterns as I have seen from Nicads..
    > > > Eneloops do take 1.5v to peak on my 2 sony Nimh chargers.

    >
    > > I have never seen a battery that will put out more voltage than the
    > > chemical action allows, and for NiMH, that is about 1.24-1.3 volts.  The
    > > 1.3 volt reading is a no-load condition on a battery fresh out of the
    > > charger, and should be considered 'transient'.  A discharged NiMH would
    > > measure about 1.0 to 1.1 volt.  I suspect you have a meter inaccuracy,
    > > and please send the URL for those 1.39-1.4 voltage numbers.- Hide quoted text -

    >
    > > - Show quoted text -

    >
    > 1.35 - 1.4v  a cell unloaded is most easily found at Wikipedia, I
    > peaked out of the sony charger at 1.5v, within a day it showed 1.4.
    > After a few shots 1.38. So what I just saw at Wikipedia shows I am
    > inline with specs. My Nicads are about the same in full v charge even
    > on my manualy done charging, peaking by just reading voltage drop, for
    > my RC toys. An auto lead acid battery is nearly discharged at 12v, so
    > are AA rechargeables.- Hide quoted text -
    >
    > - Show quoted text -


    www.batteryuniversity.com on page BU11 has interesting info on
    charging NiMh. Is it possible the chargers some people use are not up
    to the job. What I see is my voltages are correct within 0.2v on my
    meters.
    ransley, Sep 16, 2008
    #13
  14. ransley wrote:
    []
    > In using 2 digital meters that in other usage has been shown accurate.
    > Today after taking a few shots even with flash I am showing 1.38v, Its
    > time to verify my meter or get a new one. What does everyone else show
    > for V on a fully charged NiMh


    I test into a 1.3 ohm load, and show 1.25V typically. I would prefer to
    know the on-load voltage, not the open-circuit value, as it is more
    representative of actual use, and may indicate the cell condition a little
    better (i.e. poor cells will show lower voltage).

    I just tested some newer cells which I charged about a day ago and they
    show 1.34/1.35V open-circuit, and 1.28/1.29V with the 1.3-ohm load. This
    is slightly higher than I expected.

    David
    David J Taylor, Sep 16, 2008
    #14
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