Single panel, want to add another.. will this one be OK

raymate

Currently have a BP Solar Panel SX40

Max Power 40w
Volt max 16.8v
Current max 2.37a
short c current 2.58a
open c voltage 21.0v

Using a MorningStar ProStar-15 charge controller with 10 AWG cable for everything.

Want to add one or maybe two small panels, just to catch some sun around the side of my location.
Really like the look of the ALEKO panels on Amazon. 20 watt panel. They are small and seem good quality.

Spec seems to be this according to the picture shown

Max Power 20w
Volt max 18.2v
Current max 1.1a
short c current 1.21a
open c voltage 22.0v


Can I add to my PorStar different spec panels, would I be OK adding this panel, or even adding 2?

BB.

No problem at all.. Just add the extra panels in parallel to the original panel(s).

In theory, you should be adding a series protection fuse (roughly 1.56x the Isc of the solar panel rating, if they do not list a series protection fuse size). When you get ~3 or more panel in parallel, it is possible for one shorted panel to be fed too much current from the other panels can (worst case) catch fire.

Eventually, you may want to look at larger panels. Adding a bunch of smaller panels and wiring them up can be a pain. Where one larger panel is one electrical/physical connection.

Also, many times, the larger panels are cheaper ($$$/Watt) than the smaller panels (watch for shipping/insurance costs--Those can be a killer for larger panels).

-Bill

raymate

That's great news.

I have a couple of very old Amorphous silicon panels that are rated at 18w but I was never impressed with them, the ALEKO seems to be a Monocrystalline type and have far more output for the size, this 20w panel is half the physical size of my 18w old panel.

Dont even want to try and plug in the old panel I figure it would not be worth it.

BB.

Generally, and especially older, thin film panels are about 2x the surface area of crystalline solar panels. Thin film panels are less less efficient at converting sunlight to electricity.

-Bill