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The correct Diode Specifications for Solar Panels in parallel. Answered

Hello Guys I have a question,

If you connected 4 of 250Watts 24volts solar panel in parallel before connecting them to your charge controller, what would be the recommended blocking diode rating on each of these panels?

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iceng
iceng

4 years ago

Why would not a single hockey puck diode work with all four identical panels wired directly in parallel just the discharge stop ?

Or are you mounting them in different sun positions or building shadows ?

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EugeneT18
EugeneT18

Answer 4 years ago

My reason for asking is that I am concerned about the peak inverse rating on the diode.and Current rating. After the 4 solar panels are in a parallel connection it will be 24volts and the current 40amp approx. So I think I need diodes that have that or slightly higher peak inverse rating. Am I making sense?

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iceng
iceng

Answer 4 years ago

The diode only needs to block 24V lets use a 50V inverse diode for when the solar array becomes a resistor at night or cloudy day..

The 50v PRV ( Peak Reverse Voltage ) is a one way current valve that prevents your 24V Battery from pushing any current back to the solar array at night.

I'm holding a 100V PRV 700 Amp diode that wont even get warm at 160 Amps. So you could wire all 4 panels in parallel and use a single diode.

The only strange feature of Puck diodes is that you must apply about 200LBs or more of parallel force to make the diode connect...

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Josehf Murchison
Josehf Murchison

4 years ago

You are looking for a 250 W 15 +A diode like 1N5812 or MBR1635

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EugeneT18
EugeneT18

Answer 4 years ago

Thank you Josehf. I expect that after connecting the diodes to the panels and then connecting all 4 panel cables in parallel the amp after the diodes will be 4 times more. which would be approx 40amps, 24volts. So in this case I believe that you definitely confirm that the 1N5812 or MBR1635 would be perfect for this setup.

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Josehf Murchison
Josehf Murchison

Answer 4 years ago

They should be quite good, these diodes will connect to a heat sink for better heat dissipation.

If you do not have those diodes go here and use their search engine to find something.

http://ca.mouser.com/Electronic-Components/

I got 100 transistors from Mouser for the same price a 5 at Radio Shack. They are good for datasheets also.

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steveastrouk
steveastrouk

4 years ago

A 10 Amp at least. since 250/24 is roughly 10.