Charging VistaLite

On Fri, 21 Jan 2005 00:32:11 GMT, Mike Latondresse

mikelat@no_spam_shaw.ca said:

I have a 6v 7ah gel cell on my Vistalite and two chargers. One has an
output of 7.5vdc at 300ma and the other 6vdc at 500ma.

My question is will both charge the battery satisfactorily, and will
one work better than the other.

I'm too lazy to do the web research, too, but off the top of my
head...

IIRC, "6V" lead acid batteries take around 6.9V to charge fully. You
could partially charge the battery with the 6V charger, but only
partially. The 7.5V charger will take longer, because of the lower
current rating, but it will charge your battery fully. It will also
overcharge it if you leave it connected too long.

I think Sheldon has a link to a page with the "right" charger
voltages. I ended up buying a float charger to make sure I didn't
cook my battery.

Pat

Email address works as is.

I would go with the 6v, it will charge slower and increase battery life.

What I have found in my experience is chargers are really unregulated
rectified AC (think a line of McDonald's arches) and the tops of the peaks
are above their stated voltage. So a 6 volt supply will have peaks at 7.2
volts or so. So it will push a decent amount of current into a 6 volt
battery, and act somewhat as a smart charger. As the battery charges, only
the tops of the arches are above the voltage and it stops juicing the
battery so much.

"Mike Latondresse" <mikelat@no_spam_shaw.ca> wrote in message
news:[email hidden]...

Quoted message said:

I have a 6v 7ah gel cell on my Vistalite and two chargers. One has an
output of 7.5vdc at 300ma and the other 6vdc at 500ma.

My question is will both charge the battery satisfactorily, and will
one work better than the other.

Mike Latondresse wrote: (clip)will both charge the battery satisfactorily,
and will one work better than the other.(clip)
^^^^^^^^^^^^^^
I assume the ratings you are quoting are taken off the charger labels.
Since there is no reason to filter a charger output, chances are they have
either half-wave or full-wave rectified DC--and who knows how the rating is
specified: average, RMS, peak or something else? I once measured the
output voltage of an automotive battery charger, and it was less than 12
volts--yet the charger was putting current into the battery. That is
because the peaks were higher than 12 volts, so pulses of current were going
in, and gradually the battery got charged.

If you can put a current meter in series with each charger you will get an
indication of their relative effectiveness. Or, you can try them both, and
see which one brings the light up to full brightness more quickly.

See what happens when you watch oscilloscope traces...... Very good point(s)
:-)

Robert Haston said:

I would go with the 6v, it will charge slower and increase battery life.

What I have found in my experience is chargers are really unregulated
rectified AC (think a line of McDonald's arches) and the tops of the peaks
are above their stated voltage. So a 6 volt supply will have peaks at 7.2
volts or so. So it will push a decent amount of current into a 6 volt
battery, and act somewhat as a smart charger. As the battery charges, only
the tops of the arches are above the voltage and it stops juicing the
battery so much.