[Elecraft] Dead Battery

[Don Brown]

Hi

I don't see anything wrong with your setup. Maybe you just got a defectiv=
e battery. The battery should be able to charge at 13.8 volts indefinitel=
y with no damage. =20

The MFJ switching power supplies work very well I have 3 of them. The lit=
tle one without meters is only a fraction larger than a K1, weighs about =
2.5 pounds and will drive a K2/100 at 20+ amps. It has an internal pot to=
 adjust the output up a little to 14 volts. Another advantage of using a =
larger power supply is you can turn off the battery once it is fully char=
ged and keep it ready for field work.

Don Brown
KD5NDB

----- Original Message -----
From: Jeff Burns
Sent: Sunday, June 30, 2002 10:49 PM
To: elecraft_list
Subject: [Elecraft] Dead Battery

This year I started field day of running my K2 from the internal battery.
Since the club was 5A I cranked the power up to 15w. Within a few minuets=
 I
had a strange modulation of my side tone. The two-meter station even hear=
d
me, and I was on 15m CW. It took me an hour to figure out that the batter=
y
voltage was dropping below 8v causing the radio to reset with each dit an=
d
da. This was a surprise because the battery is less than a year old and i=
s
left on float charge all the time. Switching to an external battery fixed
the problem.

When I got home I charged the battery and measured the charge voltage at =
the
battery terminals. When the charger was first connected the voltage was
13.04V. After a day of charging it was at 13.89V. That looked good to me,
but the battery will not hold a charge. If I leave it unplugged for a few
hours it does the same thing it did on FD. Looks like I have a bad batter=
y.

Now my question is what caused this battery to fail in less than a year? =
The
battery was purchased from a battery supply house I found on the Internet=
,
rather than Elecraft. For a charger I use a laptop computer supply rated =
19v
and 2.64A (only cost $3). I made a box with a LM350AT voltage regulator t=
o
drop the 19v to 14v. Anything wrong with this setup?

A higher amperage supply would be nice so I could run the K2 at full powe=
r
with out the battery. I have also been tempted by the MFJ Miniature
Switching Power Supply because of it would not need the voltage reducer. =
Any
thoughts?

I will order a new battery in a few days, but do not want to have it suff=
er
the same fate as the last on.

Jeff Burns

AD9T



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