[TenTec] battery life

[Dr. Gerald N. Johnson]

On Fri, 2006-03-31 at 08:04 -0500, Ron Zond wrote:
> Hello Bob and Group
> 
> I have used TEnTec rigs and battery power for about ten years, so the
> following observations might be relevant.
> The rigs were the Scout at 50 watts, and the Argonaut V at 20 watts. The
> batteries were 33 A\h gel SLA, a good weight\power density ratio. In all
> cases, regardless of rig, the 33 A\h batteries maintained a fairly constant
> voltage over
> a 12 hour period. The change would be .3 volt at most. I wonder if running
> the Orion at reduced power (CW 5 to 30 watts)
> would be suitable? Also, I would like to know your thoughts on using
> batteries in parallel with power supply
> as a voltage regulator\charger? Interesting post; thanks for any comments
> 
> Ron
> K3MIY
> k3miy at csonline.net

For good battery life as a regulator the power supply needs to have more
precise regulation than running alone, though it can have a
significantly lower current capability than running the radio alone. The
battery chemistry needs the charging voltage held to 14.20 volts within
less than 50 millivolts variation. Going up in voltage overcharges the
battery (releasing combustible mixes of hydrogen and oxygen dampened
with sulfuric acid to eat the battery surroundings) and not reaching
14.2 volts leaves the battery less than fully charged. This optimum
voltage can be lower for deep cycle batteries that are designed to
operate at a specific gravity lower than 1.280. And the voltage is
temperature sensitive, being lowest at a comfortable room temperature
and rising as temperature goes down or up from 70 degrees F.

Most rigs work fine with voltages anywhere between 13 and 14.2 volts,
though they will nearly always put out more power at the high end of
thee range (though the variation is far less than can be detected at the
other end of a radio circuit) so the power supply without battery can
safely have poorer regulation that the one feeding the battery.

If you use a poorly regulated power supply with battery for regulation
you will regularly overcharge the battery putting out fumes and
requiring regular additions of distilled water.

Yah, the battery with power supply works. Its hardly worth the bother
(and the etched floors).

-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer