Instructables

Step By Step hack a trickle solar charger

Hello all, here is a step by step of altering a trickle solar charger I bought from harbo freight
Extensive research on small solar systems <5 watts led me to this little inexpensive ($12.99) charger from harbor freight.  Sure it is big, but it is also 12V at 1.5 watts and cost less than some 1 watt panels when shipping is included (http://adafruit.com/products/262).  it is a 22.25V open circuit but who wants that awkward voltage? 12V is a nice round number so i kept the trickle circuit and stepdown in.
I took apart the car charger part and did my own little edits to it and made it into a nice little solar source.

 
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Step 1: Taking the car port apart

The first two pictures aren't the actual car port for the trickle charger (its to my inverter).  I needed a picture to show the inside of one though, they are pretty much the same though the charger has a built in trickle circuit

Step 2: Edit the + and - leads and tape it up

Once the port is taken apart you can see the red and black wires,
Cut them off and solder an extension to them so they leave the charger body

I left the circuit in mine and in the body that way was easiest and it gave me the 12V output instead of a 22.25 open circuit voltage.  If you want the higher voltage, take it out and add a diode.

Close it up and wrap it in electrical tape and use it for what you want

Step 3: Close it up

Add a battery pack on if you want to charge a battery, it can charge small batteries, dont try to "Charge" a 12v lead acid battery with this, it is only a battery maintainer and if you charge a lead acid battery with a low current constantly you ruin your battery.  
Charging small batteries that are a lower voltage have charged fine for me.

Thanks for reading
astral_mage10 months ago
if the battery in question is alrdy near death. then go 4 it.