Is there a blue diode in the PS2 (the older one?

In a DC circuit running from solar panels to batteries do I only need one diode in series?

• in a DC circuit running from solar panels to batteries do I only need one diode in series? I am connecting a small solar panel to a battery and put two diodes in series on the positive and the negative, but when I only put one in circuit it works fine. Will this prevent backfeed back into the solar panel with only one diode in series?

• Answer:

  You only need a single diode inline between the solar panel and the battery. A diode acts like a one way valve. Place a diode on either wire effectively blocks reverse flow. You may also consider a charge controller, unless you want to manually check voltages during the day and disconnect the solar panels when the battery is charged. Otherwise, you may overcharge the battery and damage it.