Regarding alkaline batteries (AA and AAA) - capacity is a function of weight?

[Home!Guy]

I'm seeing more and more stores selling huge packages (24/32/48) packs
of AA and AAA batteries, and usually not a name brand like duracell or
energizer.

So it's a crap shoot knowing how many milli-amp hours of capacity these
batteries have.

I have a gut feeling that the amount of juice in these things is
proportional to weight.

Are there any studies or has anyone tried to correlate the weight (mass)
of a brand new AA or AAA battery with how many watt-hours can be had
from them?

[The Real Bev]

Post by Home!Guy
I'm seeing more and more stores selling huge packages (24/32/48) packs
of AA and AAA batteries, and usually not a name brand like duracell or
energizer.
So it's a crap shoot knowing how many milli-amp hours of capacity these
batteries have.
I have a gut feeling that the amount of juice in these things is
proportional to weight.
Are there any studies or has anyone tried to correlate the weight (mass)
of a brand new AA or AAA battery with how many watt-hours can be had
from them?

No idea, but we bought a couple of big packages of Maxells a number of
years ago. Every single one corroded and corroded the contacts of the
items they were used in. I can't say anything bad enough about these.

I bought a number of precharged Duracell AAs to use in my camera a
couple of years ago. Theory has it that they hold 90% of their charge
after a year. No. It's almost all gone after a few weeks, only a
little better than the normal NiMH batteries. Not happy.

I buy Kirkland alkalines when I run out. Not unhappy.

[Fred McKenzie]

Post by The Real Bev
I bought a number of precharged Duracell AAs to use in my camera a
couple of years ago. Theory has it that they hold 90% of their charge
after a year. No. It's almost all gone after a few weeks, only a
little better than the normal NiMH batteries. Not happy.

I have never tried the precharged Duracells, but expect the 90% figure
is when stored, not installed in a camera. I think most cameras draw a
small amount of current when turned off.

Over the years, I have had many items of equipment ruined due to
name-brand alkaline cells leaking. Lately, I have been using Energizer
Lithium cells for AA and AAA applications. They are more expensive than
alkalines, but Energizer claims they have much more capacity, and I have
never heard of one leaking.

Fred

[Pico Rico]

Post by Fred McKenzie

Post by The Real Bev
I bought a number of precharged Duracell AAs to use in my camera a
couple of years ago. Theory has it that they hold 90% of their charge
after a year. No. It's almost all gone after a few weeks, only a
little better than the normal NiMH batteries. Not happy.

I have never tried the precharged Duracells, but expect the 90% figure
is when stored, not installed in a camera. I think most cameras draw a
small amount of current when turned off.
Over the years, I have had many items of equipment ruined due to
name-brand alkaline cells leaking. Lately, I have been using Energizer
Lithium cells for AA and AAA applications. They are more expensive than
alkalines, but Energizer claims they have much more capacity, and I have
never heard of one leaking.

I make it a point to not leave batteries installed in things I am not
actually using. Mostly, anyway.

[The Real Bev]

Post by Pico Rico

Post by Fred McKenzie

Post by The Real Bev
I bought a number of precharged Duracell AAs to use in my camera a
couple of years ago. Theory has it that they hold 90% of their charge
after a year. No. It's almost all gone after a few weeks, only a
little better than the normal NiMH batteries. Not happy.

I have never tried the precharged Duracells, but expect the 90% figure
is when stored, not installed in a camera. I think most cameras draw a
small amount of current when turned off.

Maybe phones do, but I can't see why a camera would need to. And I'm
talking about the extra batteries that I keep in appropriate plastic
containers in my camera bag. Sometimes I get NO shots from one of these
batteries, although I know I last charged them within weeks.

Post by Pico Rico

Post by Fred McKenzie
Over the years, I have had many items of equipment ruined due to
name-brand alkaline cells leaking. Lately, I have been using Energizer
Lithium cells for AA and AAA applications. They are more expensive than
alkalines, but Energizer claims they have much more capacity, and I have
never heard of one leaking.

These are the only ones that leaked consistently.

Post by Pico Rico
I make it a point to not leave batteries installed in things I am not
actually using. Mostly, anyway.

So when the lights go out you have to look for batteries in addition to
looking for the flashlight? I finally put a pack of matches in with the
bag of candles and I can find the bag of candles in the dark.

[Gordon Burditt]

Post by The Real Bev

Post by Fred McKenzie
I have never tried the precharged Duracells, but expect the 90% figure
is when stored, not installed in a camera. I think most cameras draw a
small amount of current when turned off.

Maybe phones do, but I can't see why a camera would need to. And I'm
talking about the extra batteries that I keep in appropriate plastic
containers in my camera bag. Sometimes I get NO shots from one of these
batteries, although I know I last charged them within weeks.

Cameras have settings that are kept in memory, and at least mine
loses those settings if you remove the batteries for too long (e.g.
15 seconds). The batteries are used to keep this memory "alive".

I've seen rechargeable batteries that both hold a charge for a few
months on the shelf *AND* run down in one week in the camera.
Although I really shouldn't leave batteries in the camera that long.

[Michael Black]

Post by Home!Guy
I'm seeing more and more stores selling huge packages (24/32/48) packs
of AA and AAA batteries, and usually not a name brand like duracell or
energizer.
So it's a crap shoot knowing how many milli-amp hours of capacity these
batteries have.
I have a gut feeling that the amount of juice in these things is
proportional to weight.
Are there any studies or has anyone tried to correlate the weight (mass)
of a brand new AA or AAA battery with how many watt-hours can be had
from them?

Twice I bought noname AA cells in packs of forty at a decent price, and I
had no problems with them. I couldn't tell any shorter period of use than
others.

They literally were no name, that being the house brand for Loblaws here
in Canada.

I try to use nimhs for the heavy duty stuff, but there is still lots that
need batteries but actually suffer from rechargeables because those have a
lower voltage (and likely don't keep recovering voltage as time goes on).
Things like remotes and flashlights (which in reality means I'd like to
have them ready when needed, rather than have to search for
rechargeables or charge them up before using the flashlight). So
it was good to find a cheap source of AAs. Sadly, they dont' seem to
have that forty pack anymore. The brand name large packs are of course
more expensive.

Michael

[Gordon Burditt]

Post by Home!Guy
I'm seeing more and more stores selling huge packages (24/32/48) packs
of AA and AAA batteries, and usually not a name brand like duracell or
energizer.

How long does it take for you to use that many batteries? I'd be
worried that the shelf life expires or they leak before I get around
to using them.

Post by Home!Guy
So it's a crap shoot knowing how many milli-amp hours of capacity these
batteries have.
I have a gut feeling that the amount of juice in these things is
proportional to weight.

I've never seen a completely dead battery that crumbles to dust
(leaks and corrodes the guts of your device is something different)
or can be blown away with a sneeze, not even those tiny coin cells.

The capacity *when new* may be roughly proportional to the weight
of the battery (and the active chemicals in it) when new, comparing
only those that use the same type of chemical system (e.g. carbon-zinc,
alkaline, NiMH, Lithium-ion, Nickel-Cadmium, lead-acid, etc). Don't
count the weight of terminals, labels, plastic holders, etc.
Rechargeable batteries generally have labels with a milli-amp-hour
rating (whether that rating is accurate is another issue.)

So D cells have more ampere-hours than AA cells which have more
ampere-hours than AAA cells, provided nobody cheats and fills space
inside them with air. (There are some D-cell adapters that hold 3
AAA cells in parallel. Much of the space is plastic and air. You
may get the same voltage when fresh but it's going to wear out much
faster than a real D with the same chemical system.) Car batteries
are large because they need to be to give enough starting energy
to crank the engine, especially in cold weather.

This does *NOT* mean that a half-dead battery weighs half of a fresh
one. Aren't most types of batteries supposed to be sealed (lead-acid
being an exception for some car batteries)?

There is only a limited amount of space in an AA cell, and trying
to cram in more after it's full (to get more energy out) isn't going
to work. So all AA cells are going to weigh about the same, except
for the cheaters who fill part of the space with air.

Post by Home!Guy
Are there any studies or has anyone tried to correlate the weight (mass)
of a brand new AA or AAA battery with how many watt-hours can be had
from them?

There is the formula E = mc**2. However, don't count on being able
to measure the difference between the weight of a fully-charged
battery and a dead one. Even an atomic bomb uses only a tiny
fraction of the mass-energy of the active material (plutonium)
although you may have trouble finding all the remaining pieces to
weigh them.