I have used three small solar panels from scrapped garden ornaments to charge 4 NiCd AAA cells in an ultrasonic cat-scarer. There is a diode in -line to stop the batteries discharging back through the panels.
This unit has been working fine for over 3 months but had stopped recently. On investigation, one of the panels seems to have changed its polarity,and provide a reversed voltage when lit, so counteracting the voltage from the other two panels.
I've gone through "Am I going mad?" and "Did I measure correctly?" and the three panels are still soldered together in series so it's a definite oddity.
Does anybdy have any ideas or experience of this sort of thing at all?
This unit has been working fine for over 3 months but had stopped recently. On investigation, one of the panels seems to have changed its polarity,and provide a reversed voltage when lit, so counteracting the voltage from the other two panels.
I've gone through "Am I going mad?" and "Did I measure correctly?" and the three panels are still soldered together in series so it's a definite oddity.
Does anybdy have any ideas or experience of this sort of thing at all?