Handheld Nav/Com Radios

Jim,

I use some 2200mh NiMH AAs with a MAHA brand charger. I paid about $60 for
the charger and about $3 per battery. They do discharge about 1% per day on
the shelf but with the charger I can keep 4 of them "trickle charged"
and ready. I use them in everything and actually have 12 batteries. I
have just started using them in my new Garmin 295 (used). The previous
owner got 2.5 - 4 hours on a set of AAs. I have used my NiMH AAs for 5.5
in one day and not come close to them being dead. If you use many AAs I
would recommend looking at good rechargable AAs (not the ones you buy at
Wal-Mart).


Trip



In article , says...

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

Jim,

We are on the same page. I bought the MH-C401FS and love it. I see where they
now have a 2300maH AA battery. For anyone wanting to look at this go to...
http://www.thomas-distributing.com/mhc401fs.htm


Trip

In article , says...

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

In the long run charging a battery that fast will ruin it. They need slow
charging.


Trip

In article , says...



Jay Masino wrote:
Jim Weir wrote:

I have standardized on NiMH for all my stuff that needs a fair slug of juice t
o
run -- digital cameras, handheld radios, and the like. For clocks and such th
at
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.

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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MI-150972
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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).

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.

I have gotten away from alkaline RENEWALs.
They have a tendency to leak, damaging whatever battery holder they were in.
Also, they lose a portion of their capacity with each recharge (this
from a RAYOVAC tech and observed behavior).
The capacity of NiMH AA cells continues to increase.
At OSH this year, you could purchase 4 AA 2300 mAhr cells for $10.

TripFarmer wrote:
In the long run charging a battery that fast will ruin it. They need slow
charging.

They're like $2 each. I've already saved many times the cost of regular
camera batteries.

On 23 Aug 2004 16:18:22 GMT, (Jay Masino)
wrote:

size AAs. I'll basically be running the unit off of aircraft power, and
the batteries are just for emergencies.

Use alkalines. By the time they're dead, the unit will be obsolete, if
it is running at all.

all the best -- Dan Ford
email: (put Cubdriver in subject line)

The Warbird's Forum www.warbirdforum.com
Expedition sailboat charters www.expeditionsail.com

well


if you WANT high capacity batteries that can take the heat and have lots of
umpph and store well....

Look for LITHIUM chemistry based AA's

they have 2 to 4 times the capacity of regular alkaline AA's.....

Ive seen em at Walmart etc.....but they are usually on the counter, not with
the rest of the batteries....

And they cost 5 buck for 2 (4?), give or take a bit....

But hey, for emergency backup....whats a few buck here or there compared to all
the other BIG costs you have

take care

Blll