[ICOM] Battery Performance?

[Buck (N4PGW)]

-----Original Message-----
From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net] On
Behalf Of David J. Ring, Jr.
Sent: Wednesday, February 02, 2005 1:18 AM
To: ICOM Reflector
Subject: [ICOM] Battery Performance?

Does anyone know if the below mentioned MAHA 2300 mah Ni-MH batteries have 
more capacity than the typical premium alkaline?

I know it is best to put alkalines in my ICOM walkie when I'm just keeping 
it ready for emergencies, because I've heard Ni-MH loose the charge even 
quicker than Ni-Cad batteries.

Anyone have a quick chart on the subject, or know where this info is on the 
internet?
Or wise wisdom on the subject?  Which ones can be made to float on an ICOM 
charger without worry, etc.?

73

David N1EA


NiCads generally range from 600 - 900 Milliamp hours.
Alkalines are about 2200 Milliamp hours.
NiMH batteries vary widely from about 1300-2500 milliamp hours

The biggest differences are: Alkaline batteries have almost a linear drop in
voltage when being used.  The longer you use one, the lower the voltage
gets. The rechargables mentioned above generally hold maximum voltage until
they reach their maximum life.  Then the voltage drops off quickly.  The
advantage of this is that you can use them at full power longer, but there
is little to no warning about when they go dead.

The other difference is that the voltage of alkaline batteries starts at
about 1.6 volts with no load and slowly drops until the device can no longer
operate.  NiCads and NiMHs start about 1.2-1.3 volts and hold that level
almost until the battery is discharged.

I have discovered an advantage and a disadvantage to the NiMH batteries.
The advantage is that they don't have a memory (Mostly a problem with NiCads
in Space) and they can be recharged very many times, (I think they advertise
500 - 1000 charges).  The disadvantage is that they don't have a shelf-life!

NiMH batteries tend to die quickly if they have been charged and put on the
shelf over 5 days. This is in respect to how I use them in Digital cameras
and a two meter handheld running 5 watts on transmit.

You may see lots of fast chargers for NiMH batteries.  They range from 15
minutes to two hours.  However, the faster chargers lower the maximum number
of charges the batteries can handle.  Some chargers are smart and will
adjust their charge time or rate to the level of charge left in the battery
when it is put in the charger.  I have a 1 hour charger that came with 1300
MHA batteries.  I use it to charge my 2000 MHA and 1300 MHA batteries.  They
take two to four hours to charge in the charger unless they are not fully
discharged.  A refresher charge only takes a few minutes.

I keep an 8 pack of Alkaline batteries handy as well as keeping my NiMH
batteries charged and cycled.  Should I catch myself without charged NiMH, I
have something to fall back to.  

I probably gave you more information than you hoped for.  A search on Google
for 'battery comparison' will probably reveal lots of good info for your
entertainment.

Good luck
73 for now
Buck