[Elecraft] Battery Charging - Temperature does matter

[Wes Stewart]

Truly "smart" chargers such as those using the uc3906 IC understand this and adjust accordingly.

This does presume that the IC and the battery are located in the same environment, which isn't always exactly the case, but often close enough.

Wes  N7WS

--- On Wed, 6/10/09, John Watkins <n0evh at sbcglobal.net> wrote:

From: John Watkins <n0evh at sbcglobal.net>
Subject: [Elecraft] Battery Charging - Temperature does matter
To: "Elecraft Reflector" <elecraft at mailman.qth.net>
Date: Wednesday, June 10, 2009, 11:44 AM

I have been reading the comments about charging and floating various batteries and just had to comment on the 'law of chemistry'.

All lead acid batteries whether they are gelcel, AGM or conventional deep cycle, all work because of that dreaded course you tried to avoid in school called chemistry 101.  Chemical reactions are effected by temperature.  Most of you see this coming already.  Yes, the float voltage for lead-acid batteries to achieve proper care does change with the battery temperature.

So, if your battery storage area changes temperature from summer to winter you should make a voltage adjustment.  Mine varies from 50's in the winter to 80's in the summer.  So I use the manufactures chart to adjust my float voltage accordingly.  My settings run about 13.8 volts winter to 13.3 in the summer.  Your mileage may vary.

John - N0EVH