how can i build a trickle charger? Answered

not really interested. huh.

I have a very simple tricle charger that works off a power supply. uses a relay and a diode and a resistor And works very well without the overheating problem. cannot over charge the batt., And has a power tap for powering a shortwave radio. Interested? Private Message Me.

diode to as high current as you can (atleast 5 A)

resistor : R ohm = (volts of panel - volts of battery - 0.7) / amps of diode

for example 12 V battery / 16 V panel / 5 A diode

R = (16 - 12 - 0.7) / 5 = 3.3 / 5 = about 0.6 ohm

a 24 V 40 W or 12 V 20 W lightbulb is appropriate resistor in the example

now just connect all in series with the diode pointing from the solar panel to the battery

OR, if you are feeling more technical, get a pic chip or other transistor made for trickle charging (less than $5) and use the above procedure for plotting the rest of your design. This will allow the battery to charge at one rate, and trickle at a significantly reduced rate. This can also manage temperature, etc.