Another simple battery Charger
Real simple, no diagram is necessary
One can make a battery charger using only a 120 v light
bulb and a rectifier pulled from an old alternator.
Put 120 vac, the light bulb, the diode and the battery all in series.
The wattage of the light bulb (or other 120 v load) determines the current flow.
It would help to have an ammeter in there somewhere I would think.
I've never tried it
NOTE: never charge a battery to more than 14.5 volts. The first time
or two keep close watch on your charger. You will notice that as the
dead battery charges, the volt meter will raise higher than when you
started. Set the voltage to about 2 volts above what the meter reads
when you first hook it up to the battery before you turn it on. When
the battery comes up you can increase it a little till you get to
14.5 volt max. When the battery is charged and the amp meter drops
back to zero, you can turn it off. After while the battery will
probably drop back to 12 or 13 volts, especially if it is older. That
is expected.
DISCLAIMER: This is not a HOW TO page. This is how I did it. I do not
recommended that you attempt to duplicate this project. Go buy your
own battery charger at Walmart. This project uses high voltage that
can kill you. You can also damage your batteries, produce explosive
gasses from the batteries and get acid burns from handeling battries
or when they explode blowing the side out of your house and burning it
to the ground along with your neighbors house.