Hi All

I would like to connect multiple low-powered solar panels such as:

25W 12V Portable Solar Panel Trickle Charger Car Battery Maintainer for Boat RV | eBay

Can i simple connect all the VCC and GND together, or do i need to add diodes?

 

First, check that they don't already have diodes.
If they don't, you can connect panels in parallel if they are facing the same way (i.e. they are likely to be generating the same current and voltage).
But you should still fuse them individually.

 

Thanks

They will placed in different directions.

I am trying to charge a 12 battery.

What happens if there is no diode's used? If my charger is continuous drawing current from all of them I guess there should be no problem

 

hi DJ,
This image is a clip from that datasheet link.
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Great , so it can be directly connected

 

But watch out for the specs.
It says it is 210mm square, and appears to have a margin of about 10mm all round, so 190mm square active area. That's 0.036 square metres.
The most you can get out of a solar panel is 210W per square metre with the present technology.
0.036 x 210W = 7.5 Watts. (not 25W as advertised)

 

Hi DJ,
Note on series connected panels, 'shading' can be a problem.
The 'shaded' panel sets the current limit for the full series array.

Shading caused by trees, buildings, dirt and dead leaf litter.
E

 

But watch out for the specs.
It says it is 210mm square, and appears to have a margin of about 10mm all round, so 190mm square active area. That's 0.036 square metres.
The most you can get out of a solar panel is 210W per square metre with the present technology.
0.036 x 210W = 7.5 Watts. (not 25W as advertised)

Yes i am aware this is not accurate, i have a little project and need to keep the battery a little charged, therefore as i had about 6 pcs not being used, i thought i could use them

 

Hi DJ,
Note on series connected panels, 'shading' can be a problem.
The 'shaded' panel sets the current limit for the full series array.

Shading caused by trees, buildings, dirt and dead leaf litter.
E

I will be using them in parallel configuration

 

Hi DJ,
Note on series connected panels, 'shading' can be a problem.
The 'shaded' panel sets the current limit for the full series array.

Shading caused by trees, buildings, dirt and dead leaf litter.
E

Most commercial panels have bypass diodes and they are easy to add to string that don't.
https://www.sunwize.com/tech-notes/pv-module-bypass-diodes-what-are-they-and-what-do-they-do/

 

Hi DJ,
For reference:
Bypass diodes will allow the maximum current from the uncovered panels to flow as normal, but the total voltage of the panels in series will fall, dependent upon the number of panels bypassed.
This results in a power reduction at the output, so an MPPT module would be an important addition to the system.

I see that you have decided to use a parallel solar panel, configuration.

E