Series or parallel-mppt no shade

[Bluedog225]

I’m going to order a couple of new panels to replace my 3 old Renogy 100w. Having two modern panels will double my wattage and allow me avoid having to fuse the individual panels. E.g.:



My new Victron 150/30 will handle them either series or parallel. No partial shade is possible.

Does one way or the other matter? Or make the mppt happy (or sad)?

Thanks!

 

[Bud Martin]

If you have no shading issue then I do not see any problem using the panels in series if the total Voc is not exceed 150V.
Series connection allow you to use smaller wire gauge because the max current will be around 11A, in parallel the wire has to be able to handle 22A.
What is your system Voltage?
You can also do the comparison wiring to see what your real world result will be.

 

[Bluedog225]

Got it. A little 12 volt man cave system. I think the wire will handle either (10 gauge).

I wonder if lower current is kinder to the electronics?

And thanks!

 

[Bud Martin]

Less current = Less Vdrops on the same gauge wire.
Also less power loss.
I.E. If wire has 1 Ohm resistance, so at 1A of current = 1V Vdrops and power loss of 1V x 1A = 1W.
so at 2A, V drops = 2V, power loss = 2V x 2A = 4W.

 

[Bluedog225]

Interesting. I didn’t know that.

One other question, I’ve seen the examples of these Victrons blowing a fuse.

Wouldn’t I be be lowering the chance for that to occur with lower current?

I’m not sure what dies in the unit with over voltage. Is it also the fuse?

Thanks

 

[Bud Martin]

It looks like the Victron has a fuse on the PV input based on one of the forum member did the tear down to find why his Victron had failed.