loading
6 Comments

Tell us about yourself!

Complete Your Profile
  • Make the Harbor Freight 45W Solar Panel Charge Controller useful with a simple mod.

    This is kind of old, but just in case others are finding it, I'll offer some notes.1) Do not put blocking diodes on the battery - the whole point is that this system stores energy into the battery as well as taking it out again, so that flow needs to be two way.2) Blocking diodes on the solar panel MIGHT make sense, to avoid draining the battery into the panel at night. However, some solar panels include an internal diode, and some controllers include an internal diode, so adding another one might or might not be needed for that purpose (I don't have the unit and cannot check).3) The blocking diode reduces the voltage from the solar panel, and thus the charging power available, so adding one if not needed is actually a bad idea. If you do use a diode, make sure it has enough current r...see more »This is kind of old, but just in case others are finding it, I'll offer some notes.1) Do not put blocking diodes on the battery - the whole point is that this system stores energy into the battery as well as taking it out again, so that flow needs to be two way.2) Blocking diodes on the solar panel MIGHT make sense, to avoid draining the battery into the panel at night. However, some solar panels include an internal diode, and some controllers include an internal diode, so adding another one might or might not be needed for that purpose (I don't have the unit and cannot check).3) The blocking diode reduces the voltage from the solar panel, and thus the charging power available, so adding one if not needed is actually a bad idea. If you do use a diode, make sure it has enough current rating (and that it's placed so it's OK to get hot). A Schottky diode has less voltage drop than a standard diode. One diode with a sufficient rating is somewhat preferable to two under-rated diodes in parallel (because the two may not divide the current evenly). Since OP says he got better results with a blocking diode on the solar side, then for at least his unit it may have been needed.

    View Instructable »