NiMH cell voltage

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!"

On Sun, 14 Sep 2008 07:48:08 -0700, 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.

It would help to know what camera you are speaking of.

wrote:

On Sun, 14 Sep 2008 07:48:08 -0700, 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.

It would help to know what camera you are speaking of.

It is a Canon PowerShot A510.
--
I don't understand why they make gourmet cat foods. I have
known many cats in my life and none of them were gourmets.
They were all gourmands!

If you just used a VOM to test the voltage you won't get a worthwhile
result. You need a tester that actually loads the battery as the test is
being made. You can have what appears to be sufficient voltage in a battery
and still have low current which would cause the camera to not function or
know that the batteries need to be replaced or recharged.

"Daniel Prince" wrote in message
news
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!"

On Sun, 14 Sep 2008 07:48:08 -0700, 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.

The low voltage indicator is calibrated for 1.5 volt alkaline's. A 1.2
volt alkaline cell is dead.

Your camera was shipped with two alkaline batteries at 1.5 volts a
piece.1.2 volt NIMH batteries are a recommended option for this camera
but there is no provision on this camera to distinguish between the
two types of batteries. Therefore the factory indictor is wrong
concerning NIMH batteries.

Subsequent cameras that can use either NIMH and alkaline have
a battery switch which changes the calibration of the low level
indicator.

Run the camera until it shuts down. Then take a voltage measurement
of the NIMH. It should be about 1.1 volts. A 1.1 volt NIMH battery is
dead.

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.

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/recharge...metal_tech.asp

wrote:

Run the camera until it shuts down. Then take a voltage measurement
of the NIMH. It should be about 1.1 volts. A 1.1 volt NIMH battery is
dead.

I did that with my other set of cells. This time they were only
slightly above 1.1 volts.
--
I don't understand why they make gourmet cat foods. I have
known many cats in my life and none of them were gourmets.
They were all gourmands!

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.

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/recharge...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.