Basic Trickle Charger from Old 30 Watt Panel

[cenac86]

Hey Guys,

Im new to the solar game and I picked up an old 30 watt panel which was used to charge/maintain batteries for the fog horns for oil rigs in the Gulf of Mexico. See the attached pictures.

The bus bar in the junction box corroded from the salt air. I took it out and tested the raw wires from the panel with a voltmeter, the cells still work and produce a voltage from both sets of wires.

My goal with the panel is for use as a remote 12 volt battery trickle charger. What is the best junction box/controller I can pick up to make this happen? Thanks for checking out my thread and looking forward to getting it working! Thanks! -Will

[bcroe]

For openers find out the panel open circuit voltage and
short circuit current. That is needed to do anything.
Bruce Roe

[PNPmacnab]

A red and black may need to be connected to put the strings in series. It may be a 6V panel now the way you rewired it.

[cenac86]

I can easily undo the wire butt connectors to put the panel in series, but what junction box/controller would be needed after that?

[cenac86]

For openers find out the panel open circuit voltage and
short circuit current. That is needed to do anything.
Bruce Roe

Thanks Bruce, the second file I uploaded shows a picture of the data placard on the back if that helps.

[bcroe]

Thanks Bruce, the second file I uploaded shows a picture of the data placard on the back if that helps.

I did overlook that, but as was mentioned you will need to series
the sections to get enough potential for a 12V battery. I would
short circuit test both sections to prove it is still serviceable.
If it does hit 16VDC, you just need a regulator to limit output to
about 13.8V. And with some kind of battery blocking diode, so
it will not run the battery down when the sun does not shine.

If more current is available than you want, a resistor could limit
it. There are lots of battery maintainers available that could
work just as they are, or possibly with the original AC rectifier
section swapped for your panel. good luck, Bruce Roe