[aprssig] Battery & Charger for APRS Station

Ray Wells vk2tv at exemail.com.au
Mon Apr 21 02:20:24 EDT 2008

Lead acid batteries are better off if kept topped up and not allowed to 
deep discharge. That's not saying that some batteries can't handle deep 
cycling. They should also be periodically given a "gassing" charge.

I maintained a large(ish) solar powered radio site some years ago - 
8,000AH of batteries and solar panel capacity to deliver 100A. This was 
a 12v system.

The solar controller had two charge settings - boost, which gave a 
gassing charge, and float. The float position was interesting in that it 
cycled the batteries up to 14.4V and then switched off until the voltage 
reduced to13.4 (those figures might be out by 0.2v - the memory is going 
back 15 years). The idea was to maintain a higher state of  charge than 
floating at 13.6v, without using lots of water.

I homebrewed a similar scheme for the 12v radio battery charger in a 24v 
vehicle with great sucess.

Ray vk2tv

John Habbinga wrote:

>I am installing a digipeater in a location that I want to have
>reliable battery backup power.  For the last month or so I've been
>testing out a setup where the radio and TNC run off of a 12 volt, 35
>Ah sealed lead acid battery.
>The battery is connected to the radio/TNC and it is connected to the
>battery charger.
>The charger is a CTEK Multi US 7000.  It is a multiple stage charger.
>When it finishes charging it STOPS charging completely.  Every ten
>minutes or so the charger tests the battery and if it needs to be
>charged, then it adds current.  So it is not a 'trickle' charger.
>My observation is that about once an hour the charger kicks in and
>tops off the battery.  I don't get any interference from the charger
>at all, even on HF frequencies.  You can find out more on the charger
>I'm using at http://www.ctek.com/EN-US/Default.aspx
>At 20+ charging cycles per day, am I prolonging the battery life by
>frequently recharging when the battery is at such a shallow state of
>discharge, or shortening it?
>aprssig mailing list
>aprssig at lists.tapr.org

More information about the aprssig mailing list