[Elecraft] External battery for KX2, field day and SOTA (Eric Norris)

[Jim]

 I have two of the original A123 SLA style 7AH sized batteries, model ALM-12V7 and use them with my KX3. They have eight ANR26650 cells arranged in a 4S2P config. The ALM-12V7s can be arranged in series or parallel systems the same as ordinary SLAs. 

Internal to the battery package are the following circuit functions
- Overcharge protection and pre-charge circuits- 30 A plastic blade fuse (replaceable)- Charger detection and voltage regulation- Micro controller and cell balancing- Over discharge protection

Any discharge due to the internal circuits is so small that they recommend charging every three years if they are kept in storage. 

An ordinary lead acid charger can be used or a fixed 14.4V 10A power supply. There was no specialized A123 charger made for these batteries.
Which model of A123 battery did you have? I think some company used to sell home made packs based on individual A123 sells and that company hawked their own charger for their packs.
Jim







    On Monday, June 1, 2020, 6:06:09 PM PDT, elecraft-request at mailman.qth.net <elecraft-request at mailman.qth.net> wrote:  
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Message: 1
Date: Mon, 1 Jun 2020 07:42:45 -0700
From: Eric Norris <norrislawfirm2 at gmail.com>
Subject: Re: [Elecraft] External battery for KX2, field day and SOTA
--------------The original A123 batteries use a balancing system built into their specialized chargers, and they hold their
charge much longer.  ------------------------

73 Eric WD6DBM