Handhelds and alkaline batteries

What's the transmit power of that little handheld supposed to be anyway?

My ICOM supposedly puts out 5 watts peak.

So what's the battery solution here? Is there a battery that can (a) handle
the output and (b) not discharge while sitting in the seat pocket?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Me? I carry my handheld in my chart bag and just put the little rascals
into
the charger once a month or so. Haven't had a failure yet and I've been
using
them for 5 or 6 years. BTW, haven't replaced one in 5 or 6 years, either,
and
they still seem to have about the same battery life as when they were new.

Thanks for the primer, Jim.

Hopefully I'll never need to test them again, but our old hand-held sure
came in handy when we had a complete com failure flying into Minneapolis one
night in an ancient Apache...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"James M. Knox" wrote:
What's the transmit power of that little handheld supposed to be anyway?

The answer to that is, it depends on the battery pack the transmitter is
drawing from.
The more cells (volts and milli-amp-hours), the more power (up to a
limit).
For the old ICOM A2 and A20, I have a choice of five or six different
battery packs, each providing a different power output and
transmit/receive time.

Jim Weir wrote:

Without going into a long song and dance, 5 watts peak is what most of us call a
watt-and-a-half (CW, RMS, or any other way of saying it). Figuring that a
transmitter (overall, from synthesizer to finals) is 50% efficient, that means
you are sucking 3 watts during transmit. If the ICOM uses 4 cells, this means
that the batteries have to put out 500 mA (half an amp) during transmit. This
is pushing the limits on AA cells (see later).

According to Duracell's data sheets, Their AA Ultra battery will still be putting
out 1.2V after 1 hour at a 500 mA load and 1.1 V after 2 hours. One hour of
transmitting adds up to a lot of hours of flying.

Disregarding the scare tactics of somebody who doesn't know what they are
talking about, current state of the art NiMH batteries are by far the optimum
solution for handheld transceivers.

If you are using that transceiver every day or two or even once a week, I would
agree. For something that is used only occasionally or just for emergencies,
rechargeable batteries are a bad choice.


Yes, the self-discharge is about 30% a
**MONTH**, so if you don't go flying for a month, the batteries are down to 70%
the next time you go to the airplane. Big flippin' deal.

So I got the details wrong, "big flippin' deal". The fact still remains that NiMH
batteries have the worst (highest) self discharge rate of any of the commonly used
battery chemistries. You didn't get all the details right either, I looked them up
again. NiMH batteries loose 15 to 20% of their capacity in the first 24 hours
after charging and then 15 to 20% more per month. You may find this acceptable for
emergency equipment, but I don't. Put in Alkaline or non rechargeable Lithiums and
you can forget about it for 2 to 5 YEARS, that's a lot better than having to
remember to charge it every month or two.


You can now get AA NiMH cells (http://www.thomas-distributing.com/batteries.htm)
with 2200 mAh ratings, which should be good for six months, even WITH
self-discharge. You can also go the thomas FAQ page for the truth about
self-discharge instead of listening to a ranting from somebody who didn't do
their homework.

The nice part about both NiMH and nicad are that you can draw AMPS from them
without getting into internal resistance effects. They will put out five to ten
times the short-circuit current than will a regular alkaline cell.

NiMH don't have "memory" (nicads, more or less, still have some memory), which
means that if you don't completely discharge them before charging them, they
"remember" the level at which they were discharged and won't go any lower. NiMH
do not exhibit this effect. NiMH also have many more charge-discharge cycles
than do nicads.

Who's not doing their home work now? According your source, NiMH batteries are good
for 250 to 500
cycles and NiCd are good for 500 to 1,000 cycles. While NiMH have a significantly
lower tendency to develop memory that the old NiCds were so bad about, they still do
(according to most of the material I have read) have a slight tendency to developing
a memory. Even your source recommends periodic conditioning of NiMH, why would you
need to if they didn't have any memory tendency?

Did you even read the source I posted? Here is another one.

http://www.cadex.com/b_02_2_0_nickel.asp


--
Chris Woodhouse
Oklahoma City

"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety."
-- Benjamin Franklin, 1759 Historical Review of Pennsylvania

Casey Wilson wrote:

Quote all the 'documents' you want -- my real-life experience proves to
me that NiMH are by far superior to alkaline batteries.

That's like saying aluminum is far superior to steel. In reality it depends on
the situation.


Expensive, yes.
Worth it, you bet! They're what will go in my handheld and I'm willing to
trust my family's safety to them.

I'm not trying to say NiMH are worthless. In fact in the situations you
describe they are an excellent choice. However for something that is only used
briefly at very rare intervals, such as a hand held Tx that is carried for the
sole purpose of back up for when the panel radio dies, non rechargeable
batteries are the way to go. Stick them in the radio today, and 18 months from
now when I need it, I can be confident that they are still going to work.

As a side note; when it comes to rechargeable batteries, I don't know why every
one dismisses NiCd's so quickly. In many applications I think they are arguably
as well suited as NiMH. They are cheaper, have a greater number of cycles
before they die, and the memory effect which is no longer as bad as some would
have you believe, is rather easily managed with the right charger and by using 2
battery packs.


--
Chris Woodhouse
Oklahoma City

"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety."
-- Benjamin Franklin, 1759 Historical Review of Pennsylvania

Chris W wrote in message ...
Morgans wrote:

Chris, can you quote a source on the 10% discharge per day on the NiMH? I
have not found that to be the case.
--
---Jim in NC---

http://www.allegromicro.com/techpub2/cadex/index32.htm

apperently I didn't remember the details exactly right but the fact that NiMH
have a very bad self discharge rate is true. In fact rechargable batteries as a
group have a self discharge rate that is a lot worse than most non rechargable
batteries.

From the link you supplied:

"Self-discharge: Both NiMH and NiCd are affected by reasonably high
self-discharge . The NiCd loses about 10% of its capacity within the
first 24 hours, after which the self-discharge settles to about 10%
per month. The self-discharge of the NiMH is one-and-a-half to two
times higher than that of the NiCd. Selecting hydride materials that
improve hydrogen bonding to reduce self-discharge typically also
decrease the battery capacity."

So it's more like 10% for the FIRST day, then 10% per MONTH
thereafter.

SM

"Chris W" wrote in message
...
Casey Wilson wrote:

Quote all the 'documents' you want -- my real-life experience proves
to
me that NiMH are by far superior to alkaline batteries.

That's like saying aluminum is far superior to steel. In reality it
depends on
the situation.

No, your metaphor doesn't work. We are talking about batteries.

I'm not trying to say NiMH are worthless. In fact in the situations you
describe they are an excellent choice. However for something that is only
used
briefly at very rare intervals, such as a hand held Tx that is carried for
the
sole purpose of back up for when the panel radio dies, non rechargeable
batteries are the way to go. Stick them in the radio today, and 18 months
from
now when I need it, I can be confident that they are still going to work.

I think part of the trip planning check list should include checking
the spare (read emergency) radio. Particularly if it is an item you might
want to depend on in a critical situation. Stashing it somewhere for months
doesn't seem like a safe idea.
I plan on using mine every time I go flying. Like, listening to ATIS or
calling ground before cranking the engine. Seems to me that would save some
time on the Hobbs.

As a side note; when it comes to rechargeable batteries, I don't know why
every
one dismisses NiCd's so quickly. In many applications I think they are
arguably
as well suited as NiMH. They are cheaper, have a greater number of cycles
before they die, and the memory effect which is no longer as bad as some
would
have you believe, is rather easily managed with the right charger and by
using 2
battery packs.

My post was aimed at alkaline batteries. But since you mentioned them,
my personal experience with NiMH versus NiCad is pretty much the same. NiCad
batteries have not lived up to the heavy power drain of my camera. I don't
expect them to work any differently in a handheld Xceiver.
I used to use NiCad in my RC equipment. Same thing. Memory effect
aside, NiCads just have not performed as well as NiMH. Also, I've tossed a
lot of NiCad batteries that went kaput before NiMH went on the market. I'm
still using every NiMH I've ever bought. No, I take that back.... a thief
stole a camera bag along with eight batteries last month. I did replace
those.
Maybe my experience is enigmatic. Do what feels good for you. I don't
condemn you or NiCads.

Regards,

Casey

Squirrel wrote:

http://www.allegromicro.com/techpub2/cadex/index32.htm

From the link you supplied:

"Self-discharge: Both NiMH and NiCd are affected by reasonably high
self-discharge . The NiCd loses about 10% of its capacity within the
first 24 hours, after which the self-discharge settles to about 10%
per month. The self-discharge of the NiMH is one-and-a-half to two
times higher than that of the NiCd. Selecting hydride materials that
improve hydrogen bonding to reduce self-discharge typically also
decrease the battery capacity."

So it's more like 10% for the FIRST day, then 10% per MONTH
thereafter.

For NiCd that is right, but is also says up there in the section you quote that NiMH
has 1.5 to 2 times higher self-discharge than NiCd so 15-20% the first 24 hours and
15-20% per Month after that.


--
Chris Woodhouse

"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety."
-- Benjamin Franklin, 1759 Historical Review of Pennsylvania

Casey Wilson wrote:

"Chris W" wrote in message
That's like saying aluminum is far superior to steel. In reality it
depends on the situation.

No, your metaphor doesn't work. We are talking about batteries.

I think my analogy is just fine. There are times when aluminum fits the
application best and times when steel is a better choice. With batteries there
are times when rechargeable are handy to use and times when non rechargeable are
a better choice. I don't see how you can disagree with that when you consider
this situation? The battery in my watch went for almost 4 years before I had to
change it, would you use a rechargeable in that watch if you could? Of course
not, it would discharge its self faster than the watch discharged it. There is
room to disagree on where the line of when to use rechargeables vs non
rechargeables is, but the line does exist.

I think part of the trip planning check list should include checking
the spare (read emergency) radio. Particularly if it is an item you might
want to depend on in a critical situation.

If I was going on a long XC I probably would do that, but for short flights of
an hour or so I doubt many people would go to the bother, I wouldn't.


Stashing it somewhere for months
doesn't seem like a safe idea.
I plan on using mine every time I go flying. Like, listening to ATIS or
calling ground before cranking the engine. Seems to me that would save some
time on the Hobbs.

From the perspective of flying my own home built, I wouldn't be doing that.
However if you do and the battery life of alkaline is short enough that you need
to replace them every 2 or 3 trips then I can see using rechargeables. I don't
know how long they would last in that situation, I would check first.


My post was aimed at alkaline batteries. But since you mentioned them,
my personal experience with NiMH versus NiCad is pretty much the same. NiCad
batteries have not lived up to the heavy power drain of my camera. I don't
expect them to work any differently in a handheld Xceiver.
I used to use NiCad in my RC equipment. Same thing. Memory effect
aside, NiCads just have not performed as well as NiMH. Also, I've tossed a
lot of NiCad batteries that went kaput before NiMH went on the market. I'm
still using every NiMH I've ever bought. No, I take that back.... a thief
stole a camera bag along with eight batteries last month. I did replace
those.
Maybe my experience is enigmatic. Do what feels good for you. I don't
condemn you or NiCads.

I've never had any problems with NiCd when I was doing RC, One thing that is a
problem is using a battery pack with enough capacity. Generally a pack with
twice the capacity will last a lot more than twice as long because the current
drain is a lower percentage of the batteries ratting. Since NiMH batteries
normally have more capacity than a NiCd of the same size that may be why the
NiMH were working so much better for you. If you could use a larger NiCd
battery I think you would find they work about as well as the NiMH. I think
that designers of electronic equipment, in an effort to design as small as
possible, often use a battery that is too small for the load requirements, in a
case like that if you put NiMH batteries than generally have the higher capacity
for the same size battery you are going to see a big improvement because the
NiMH is sized more appropriately for the load. I am having that exact problem
with a cordless phone right now. It comes with a 850 mAh NiCd and it goes dead
every time you turn around. If you replace it with the alternate 1200 mAh NiMH
the battery life is very good. If I could fit a 1200 mAh NiCd in the phone I am
sure it would do just fine as long as the memory problem was managed.


--
Chris Woodhouse
Oklahoma City


"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety."
-- Benjamin Franklin, 1759 Historical Review of Pennsylvania

Has anyone else tried transmitting using a handheld powered by alkalines,
either the A23 or any of the other brands? I'm thinking about trying the
Sporty's model next. It uses 8 AA rather than the A23's 6.

I use my handheld as sole radio, so the rechargable batt is far better
for me. That was a major reason I sold the Sporty's--the batts cost
too much and throwing them away embarrassed me in front of my very
green daughter.

I never had a problem with the Sporty's such as you describe. It's
true with all handhelds that they will receive long after they fail to
transmit. If anything, my feeling is that the aky batts ought to be
better when new than the ni-cads (whatever).

I like my present (Yaseu) handheld much better than the Sporty's, for
what it's worth. Can't you get an alky adapter for your present kit?

all the best -- Dan Ford
email: www.danford.net/letters.htm#9

see the Warbird's Forum at www.warbirdforum.com
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