Handheld Nav/Com Radios

I concur.

NiCad batteries (with their "memory" flaw) are a technology of the
past. Alkaline batteries have a shelf life measured in years, so self
discharge is a non-issue, unlike NiCads.


Exactly wrong. NiCads don't have a memory problem and alkalines self
discharge like crazy. I'd be happy to supply the research data proof
on the NiCads and if you want to lose the self discharge problems go
with a lithium battery pack. I'd just stick with fresh alkalines for
a couple of bucks, and do.

"Dave Burton" wrote in message
...
Exactly wrong.

Huh? Describing your own post?

NiCads don't have a memory problem

Of course they do. Continually charge them before they are fully discharged
and you will find they no longer take a full charge. There's a dramatic
difference in lifetime between a NiCd battery that is always fully
discharged and one that's not, with the always-discharged one coming out way
ahead.

and alkalines self discharge like crazy.

If by "self discharge like crazy" you mean "hold a charge for years", then
you're right. Otherwise, you're on crack.

I'd be happy to supply the research data proof
on the NiCads

I've got all the research data proof I need, having both killed NiCd
batteries early, and babied NiCd batteries to decade long lifetimes.

and if you want to lose the self discharge problems go
with a lithium battery pack.

Li-ion batteries self-discharge way faster than alkalines. To make matters
worse, if you allow them to be stored at full charge, they wind up with a
"memory effect" very similar to that found with NiCd batteries (albeit for a
different reason).

There hasn't been a 'memory' problem in nicads for decades. It is an old
tale that is untrue. Over charging NiCAD can cause volatge sag issues but if
you have a decent charge that is not a problem. LiION, NiMH on the other
hand have a much higher energy density per unit of weight than NiCad but
they self discharge very quickly. They also have a finite life of only a few
hundred charge/discharge cycles. For radios that sit in your flight bag you
are much better to use NiCad's. But even those are discouraged for use
because of disposal issues. Cadmium is very bad for the environment. That
means the best overall solution is probably NiMH.

Scott

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"Peter Duniho" wrote in message
...
"Dave Burton" wrote in message
...
Exactly wrong.

Huh? Describing your own post?

NiCads don't have a memory problem

Of course they do. Continually charge them before they are fully
discharged
and you will find they no longer take a full charge. There's a dramatic
difference in lifetime between a NiCd battery that is always fully
discharged and one that's not, with the always-discharged one coming out
way
ahead.

and alkalines self discharge like crazy.

If by "self discharge like crazy" you mean "hold a charge for years", then
you're right. Otherwise, you're on crack.

I'd be happy to supply the research data proof
on the NiCads

I've got all the research data proof I need, having both killed NiCd
batteries early, and babied NiCd batteries to decade long lifetimes.

and if you want to lose the self discharge problems go
with a lithium battery pack.

Li-ion batteries self-discharge way faster than alkalines. To make
matters
worse, if you allow them to be stored at full charge, they wind up with a
"memory effect" very similar to that found with NiCd batteries (albeit for
a
different reason).

Dave Burton wrote:

.... alkalines self discharge like crazy.

I've never seen any evidence of this in any appliance I've owned. The battery in my
multimeter is still good after 15 years, for example.

George Patterson
If you want to know God's opinion of money, just look at the people
he gives it to.

Pretty close to right.

Early nicads had a terrible memory problem. Today's nicad chemistry has gone a
long way towards solving the problem, but has not completely eliminated it. The
main problem with nicads today is shelf life due to self discharge and the nasty
chemistry when they go to the landfill.

Alkalines (including rechargeable alkalines) have what is called "five year
chemistry". That is, they can sit on the shelf for five years and still give
rated output when put into service.

NiMH are the poor shelf life that you were probably thinking of. Excellent
power/weight/size ratio, but very poor in the self discharge arena.

Li-ion is probably the best mix of all, but expensive.

Jim



(Dave Burton)
shared these priceless pearls of wisdom:


-
-Exactly wrong. NiCads don't have a memory problem and alkalines self
-discharge like crazy. I'd be happy to supply the research data proof
-on the NiCads and if you want to lose the self discharge problems go
-with a lithium battery pack. I'd just stick with fresh alkalines for
-a couple of bucks, and do.

Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com

NiMH are the poor shelf life that you were probably thinking of. Excellent
power/weight/size ratio, but very poor in the self discharge arena

Is that in terms of only self discharge...ie the power stored quickly goes to
zero?

Or is it in terms of being stored for long periods of time (and therefore
sitting in a discharged state) they are actually ruined permanently?

Because I have A BUNCH of these suckers I got really cheap and have been in
storage for years......and I'd hate to think they have gone bad for good!

take care

Bllll

Jim Weir wrote:
Early nicads had a terrible memory problem. Today's nicad chemistry has gone a
long way towards solving the problem, but has not completely eliminated it. The
main problem with nicads today is shelf life due to self discharge and the nasty
chemistry when they go to the landfill.
SNIP
NiMH are the poor shelf life that you were probably thinking of. Excellent
power/weight/size ratio, but very poor in the self discharge arena.

Jim,

I need to buy a set of rechargables for my new AvMap EKP-IV. It takes
size AAs. I'll basically be running the unit off of aircraft power, and
the batteries are just for emergencies. So, every time I fly they'll be
being recharged, and very rarely used. Do you recommend Nicads or NiHH?

--- Jay



--
__!__
Jay and Teresa Masino ___(_)___
http://www2.ari.net/jmasino ! ! !
http://www.oceancityairport.com
http://www.oc-adolfos.com

I have standardized on NiMH for all my stuff that needs a fair slug of juice to
run -- digital cameras, handheld radios, and the like. For clocks and such that
suck microamps, I have standardized on alkaline Renewals (*). If it was mine,
I'd use NiMH. I have found the best source to be Thomas Distributing for
quality AND price.

(*)... and I change the clock batteries throughout the house and hangar at the
semiannual DT/ST time change, keeping a spare set charged up a couple of days
before.

Jim



(Jay Masino)
shared these priceless pearls of wisdom:


- I need to buy a set of rechargables for my new AvMap EKP-IV. It takes
-size AAs. I'll basically be running the unit off of aircraft power, and
-the batteries are just for emergencies. So, every time I fly they'll be
-being recharged, and very rarely used. Do you recommend Nicads or NiHH?
-
---- Jay



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:
I have standardized on NiMH for all my stuff that needs a fair slug of juice to
run -- digital cameras, handheld radios, and the like. For clocks and such that
suck microamps, I have standardized on alkaline Renewals (*). If it was mine,
I'd use NiMH. I have found the best source to be Thomas Distributing for
quality AND price.

Thanks!


--
__!__
Jay and Teresa Masino ___(_)___
http://www2.ari.net/jmasino ! ! !
http://www.oceancityairport.com
http://www.oc-adolfos.com

Jay Masino wrote:
Jim Weir wrote:

I have standardized on NiMH for all my stuff that needs a fair slug of juice to
run -- digital cameras, handheld radios, and the like. For clocks and such that
suck microamps, I have standardized on alkaline Renewals (*). If it was mine,
I'd use NiMH. I have found the best source to be Thomas Distributing for
quality AND price.


Thanks!

I use rechargeable Energizer 2300 mAh NiMH in my digital camera and GPS.
They take a half hour to charge and probably take about 200
pictures, although that will depend greatly on how much you use the
screen on the back of the camera.