[Elecraft] K2 Battery Shelf Life

[Charles Greene]

Darrell,

The battery should last about 300 cycles, full charge to full discharge.  I 
don't know how many years if you take care of it.  It works best when you 
keep it on constant float when not in use.  The Elecraft manual suggests a 
method of floating the which consists of increasing the power supply 
voltage to 14 to 14.2 volts and keeping it on to float the battery when not 
in use.  I bought a Power Sonic automatic charger and use it in lieu of the 
suggested Elecraft method, so I can turn the power supply off.  The power 
sonic charger is a smart charger and knows when to charge and when to 
float, so it possibly takes better care of the battery than just float 
charging it.  I keep the battery switch off unless I am using the battery 
with a separate, fused connection direct to the charger.  My battery still 
is in good condition, and it is going on 5 years old!

Once my battery apparently died due to neglect on my part.  Placing on the 
automatic charger and cycling it once restored it.  Other SLA batteries I 
own have died through neglect and have not restored, so the 32 months of 
sitting discharged may have done it in.  Its worth a try to restore.  The 
charging rates for each battery are listed on the Power Sonic web site, so 
using an ammeter and a controlling the voltage of power supply, you can 
possibly restore it.  It seems worth a try.

At 11:24 PM 1/23/2004, Darrell Bellerive wrote:
>I am finally getting around to finishing my K2. The battery has not been
>installed in the K2 and has been sitting in it's box for the last 32
>months. The voltage reads 11.42 volts with my cheap Radio Shack DMM.
>
>The battery is one supplied by Elecraft and is a Power Sonic Model
>PS-1229 12 Volt 2.9 Amp. Hr. with a sticker on top that reads 06060 or
>09090 depending on one's perspective.
>
>I would like some advise on what to do with the battery. Has it reached
>the end of it's shelf life? Should it just be replaced? Should I try to
>charge it and if so, what is the best way to charge it?
>
>I have a Diawa PS-300 30 amp 12 volt power supply with variable voltage
>control. It is adjustable from about 11 to 15 volts. Can this be used to
>try to charge the battery? If so what is the recommended voltage and
>procedure.
>
>Darrell
>VE7CLA
>K2 #1973
>
>
>_______________________________________________
>Elecraft mailing list: Elecraft@mailman.qth.net
>You must be subscribed to post to the list.
>To subscribe or unsubscribe see: 
>http://mailman.qth.net/mailman/listinfo/elecraft
>Elecraft Web Page: http://www.elecraft.com
>Also see: http://www.elecraft.com/elecraft_list_guidelines.htm