Author Topic: Cheap solar panels with no diodes.  (Read 1103 times)

Jacarandat

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Cheap solar panels with no diodes.
« on: January 28, 2020, 01:43:56 PM »
I bought solar panels to go with my classic charge controller, but I found that there are no diodes in the solar panels. Do I need to worry about power draining from the battery back into the solar panels? If so what's the best solution?

boB

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Re: Cheap solar panels with no diodes.
« Reply #1 on: January 28, 2020, 02:19:20 PM »

If you have panels in series then yes, you will most likely want to add diodes.

Sometimes the diodes are built into the junction box on the panel but I suppose if the panel is small enough, then they might not be assuming you are using more than one panel in series.

A single PV panel or multiple panels in parallel shouldn't need diodes though since there would be no reverse current to worry about.

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Kent0

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Re: Cheap solar panels with no diodes.
« Reply #2 on: January 28, 2020, 10:34:53 PM »
The diodes installed in most solar panels are bypass diodes. They provide a path for current (power) to flow through a shaded module. They are essential if there are modules wired in series. Generally series diodes are not necessary because all reputable charge controllers and inverters provide a method to prevent reverse power flow to the PV array. So, don't add series diodes. And don't wire PV modules lacking bypass diodes in series.

boB

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Re: Cheap solar panels with no diodes.
« Reply #3 on: January 29, 2020, 01:57:21 AM »
Oh !   I was thinking bypass diodes, not series diodes for night leakage...   

......sounds kind of like an situation needing diapers    :)

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