Handhelds and alkaline batteries

See? Already I'm thinking like a politician. Normally, I would have said,
"Bull$#it", but instead I'm saying, "Isn't that an interesting untruth."

{;-)


Jim


Chris W
shared these priceless pearls of wisdom:


-
-For an emergency only radio, NiMH are about the worst battery to use. They
have a
-self discharge rate of 10% per day.
Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

Jim Weir wrote:

See? Already I'm thinking like a politician. Normally, I would have said,
"Bull$#it", but instead I'm saying, "Isn't that an interesting untruth."

Looks like I was wrong NiMH batteries have an even worse self discharge rate than
I had remembered and NiCd are next and then the Lithium Ion

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


--
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
...
Jim Weir wrote:

Alkalines have a problem when you get to the power levels we are talking
about
for transmit. They last a mercifully short time in most HTs. We've
found that
popping for the NiMH cells is far better from a time and life point of
view.

For an emergency only radio, NiMH are about the worst battery to use.
They have a
self discharge rate of 10% per day. The Lithium Ions are the next best
then
NiCd. Of course the self discharge rate of alkaline batteries are a lot
better
than any of the rechargeable but they don't do well with high current
loads that
some electronic equipment need. The non rechargeable Lithium batteries
are the
best in that regard, they last a long time, lowest self discharge rate of
any
battery and they can take the high current loads, the only down side is
they are
expensive, especially if you go to the corner drug store where they some
times will
charge $8 or more each, if you look around on the internet you can get
them for
less than $2 each. Of course that doesn't do much good if your radio
doesn't have
a pack that will take the CR123 lithium batteries.


--
Chris Woodhouse
Oklahoma City

"They that can give up essential liberty
to obtain a little temporary safety

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---

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.

--
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

"Jim Weir" wrote

Try www.thomasdistributing.com Probably the best price in the country.

Jim

How about the "quest" brand at walmart? Less than 9 bucks for 4 1500mah
AA's. Can they beat that?

--
---Jim in NC---

Jim Weir wrote in
:

Alkalines have a problem when you get to the power levels we are
talking about for transmit. They last a mercifully short time in most
HTs. We've found that popping for the NiMH cells is far better from a
time and life point of view.

The trouble with NiMH in a handheld used for emergencies (i.e. toss it
into the flight bag and forget it) is the HORRIBLE self-discharge rate.
Basically you need to recharge then every couple of months - especially
if they are kept in a warm environment. [Worst case self-discharge rate
is listed at 3% per day!!! NiCad is almost as bad, at 1% per day.
Note that both of these are WORST CASE.]

Alkalines are great at shelf life, but as Jim (furture govenor) says,
they may not support the current draw during transmit.

Two possible tests:

1. Put a scope directly on the battery pack during transmit - if you can
see the modulation (or any significant change), that's the problem.

2. If the result of step 1 is that you actually see the modulation (as
opposed to the overall voltage simply dropping too low) then it might be
possible to rig a super-cap across the battery.

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

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------

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"

"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.

I don't own Energizer (ENR) or Duracell (G) stock and I don't think Jay does
either. We just stopped by the closest battery booth and that's what was
readily available for alkalines.

"mike regish" wrote in message
news:UOcYa.54566$cF.19421@rwcrnsc53...
Bet he owns stock in Energizer...

I use Duracell in everything. (And no, I don't own any stock)

mike regish


"Greg Burkhart" wrote in message
news:YocYa.81797$o%2.37792@sccrnsc02...
"Ross Oliver" wrote in message
...
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 don't have direct experience with the Icom radios, but I was with Jay
Honeck when he picked up his A5 at OSH. The dealer mentioned when using
alkalines in the Icom, don't use Duracell brand. He said there was a
'compatibility' problem when using that brand for some reason. Jay
picked
up
a set of industrial Energizers and used his new handheld for a few days
without any problems.