How would you wire 3 Solar Panels?

Nostrodamus

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Having decided to fit semi flexible solar panels to my boat I am in a quandary on the best way to wire them up and get the most power from them.

I have a large raised saloon roof but the control lines back to the cockpit go over it casting a permanent shadow. I thought it best that I fit three panels, one in the centre and two either side avoiding the lines. (I will still get a shadow from the boom over one of the panels at various times)

I have a house battery bank, a dedicated start battery, two alternators, a Hearth freedom 10 inverter and a Link 2000 battery monitor and inverter/charger control.

Should the panels be wired together or separately?

Do I need a regulator for each panel or just one that can charge both battery banks?

How many blocking diodes do I need and should the resultant feed go straight to the batteries or through the battery monitor?

Do I need a MPPT and where does this fit in?

I thought solar panels were strait forward but I certainly need help. Any explanation or diagrams would be more than welcome.
 

noelex

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You don’t say the size of your panels but my recommendation to you would be:
Wire them in parallel (All the + wires from the solar panels joined together and all the - wires from the solar panels joined together. The join is most commonly near the solar panels with 1 thicker wire to the battery, but they can be joined anywhere that’s convenient) The wires should be attached before the battery monitor so it will read the current in
Only charge the house battery with the solar panels (as long as the start battery is not left without any charge for long periods)
Use a single non MPPT regulator with 3 or 4 stage PWM charging.
You do not need any extra diodes.
 
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Nostrodamus

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Thank you Noelex, you have made most of it strait forward and easy to understand apart from the link battery monitor/charger. From what I understand it should go through this before going to the batteries. Am I correct?
 

noelex

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Thank you Noelex, you have made most of it strait forward and easy to understand apart from the link battery monitor/charger. From what I understand it should go through this before going to the batteries. Am I correct?
Yes connect the solar panel to the regulator then connect the negative wire from the regulator to the shunt for the battery monitor. The + wire is usually connected to a fuse or circuit breaker then to the to the + side of the battery switch. Your regulator may require some additional wiring and will usually come with a wiring diagram.
 

VicS

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As Noelex says. All three panels in parallel. Assuming the individual panels have integral diodes no extra ones are required otherwise a diode will be required for each panel

A single regulator is all that is required. MPPT would give you the the maximum possible from the panels but at an increased cost. It may or may not be worth the extra.

Yes panel output must go though the battery monitor shunt , not directly to the battery, or the monitor will not record the panel output.

The manual for the Link 2000 is HERE Wiring diagrams on pages 40 & 41
 

Nostrodamus

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Thank you all so much for your help.
What I need and how to wire them on the positive side seems pretty strait forward.
On the negative side it just seems like it needs to be connected to a brown wire on the negative side of the inverter.
I think I will turn my mind to solving the middle east crisis and have an electrician take a look.
 
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