[Elecraft] Battery Charging with DC Power Supply

[Wes Stewart]

Finally, a voice of reason.

--- On Sun, 6/7/09, dave <hottell at gulftel.com> wrote:

From: dave <hottell at gulftel.com>
Subject: Re: [Elecraft] Battery Charging with DC Power Supply
To: mzilmer at verizon.net
Cc: Elecraft at mailman.qth.net, "Bill Miner" <wg6h at yahoo.com>
Date: Sunday, June 7, 2009, 11:36 PM


I'm not quite sure what is meant by the term 'uncontrolled source'. A 
regulated power supply makes a fine battery charger. Review the 
charging recommendations at the various battery manufacturer sites 
such as here:

<http://www.power-sonic.com/index.php?doc_id=116>

or here:

<http://www.powerstream.com/SLA.htm>

and you will see that constant voltage charging is one of several 
recommended charging methods.

The charge voltage needs to be carefully regulated, which Aston and 
other power supplies should do, and it is certainly a very good idea 
to put a fuse in line with each battery to protect against the unknown.

But there is absolutely nothing wrong with constant voltage float 
charging. At the phone co. we kept batteries on float charge for 20 to 
25 years and they were instantly ready, indeed constantly on line, and 
fully charged.

Keep the charge voltage set correctly, use proper safety precautions, 
follow the battery manufacturer's recommendations, and you should be fine.

The recommended charge voltage varies by the type of battery. Flooded 
batteries require a somewhat lower voltage than do SLA or AGM types. 
For flooded cells the usual recommendation is about 13.5 to 13.6, but 
some manufacturers are lower than this, and for AGM it is usually a 
bit higher at 13.6 to 13.8. Check with the battery manufacturer to be 
sure.

What you are trying to do is keep the battery fully charged but yet 
not burn off the water nor damage the plates.


73 de dave
ab9ca/4