Hello from Maypearl Texas. Newb to Solar.

[Sunking]

Why are the smaller wattage panels better than say a 60-cell 250W+ type of module for that? Aren't they set up in series? Just interested if I ever wanted to add a small sub-system to my existing system for a battery backup "hobby" system.

It is just the math and 200 watts is a very good common denominator as a building block. For example take a Morningstar TS-45 or 60 MPPT controller maximum panel input power limits vs battery voltages.. For the 45 is:

600 @ 12
1200 @ 24
2400 @ 48

For the 65 is:

800 @ 12
1600 @ 24
3200 @ 48

If you were to use 250 watt panels you would not be able to max out either controller. However with 200 being the common denominator you can. 100 also works.

[hztd0m]

If you were to use 250 watt panels you would not be able to max out either controller. However with 200 being the common denominator you can. 100 also works.

Another newb question. These beauties Kyocera KD215 are little tough to find (I may not be looking in the right part of google though). If I were to use 2 x 100 watt panels.

Here we go.

2 x 100 watt panels in parallel, 2 batteries in parallel = Increase battery aH, Increase current, only be able to be 12v system (for the purpose of the inverter.)

If I were to use 1 x 200 watt panel I would have the 12v, 24v, 48v capability. I can't do that with the 100 watt set up can I.

[Sunking]

If I were to use 1 x 200 watt panel I would have the 12v, 24v, 48v capability. I can't do that with the 100 watt set up can I.

No not with a single 100 watt panel. For every 12 volts of battery, you need 18 Vmp of panel or 36 cells. 100 watt panels in all likelihood are standard battery panels of 36 cells which will have a Vmp of 18 volts. For each cell in a panel you get roughly .5 volts. See the connection?

So for a battery system minimum Vmp is

18 volts @ 12
36 volts @ 24
72 volts @ 48

[hztd0m]

Good morning!

Its been a while since I have been to the forum, life happens.

I have been reading and searching and all this solar is still pretty overwhelming.

Been sticking to this rule of thumb provided.

"It is just the math and 200 watts is a very good common denominator as a building block. For example take a Morningstar TS-45 or 60 MPPT controller maximum panel input power limits vs battery voltages.. For the 45 is:

600 @ 12
1200 @ 24
2400 @ 48

For the 65 is:

800 @ 12
1600 @ 24
3200 @ 48

If you were to use 250 watt panels you would not be able to max out either controller. However with 200 being the common denominator you can. 100 also works."

I have been looking into the Kyocera KD320GX-LFB or KD325GX-LFB. Honestly dont under stand 320 vs 325 difference. With this panel do my numbers follow or is it:

650 @ 12
1300 @ 24
2600 @ 48

What I am trying to do is use a good quality panel that I can expand upon and not have to buy all kinds of different parts when my system gets bigger. In my searching the 200 panel building block is a tough one to find.

The ultimate plan would be to put back to the grid and use a small battery system if need be.

These are the specs for the panel.

http://www.kyocerasolar.com/assets/001/5616.pdf