Can I wire in parallel BEFORE series?

[jasonl549]

I have (4) 12v solar panels that I want to wire in parallel and series to achieve 24v. These panels come in sets of 2 and come with mc4 connectors that basically wire the 2 panels in parallel. Now I have a second set of these panels and so I essentially have 2 sets of parallel wired panels. My question is can I wire these 2 sets in series to achieve 24v without hurting anything? All the wiring diagrams that I see have the panels wired in series and THEN in parallel. In order to avoid having to hack up my existing factory wiring and ordering more connectors and more wire, I would like to simply hook these 2 strings up in series with each other.

Thanks in advance.

[Shockah]

I have (4) 12v solar panels that I want to wire in parallel and series to achieve 24v. These panels come in sets of 2 and come with mc4 connectors that basically wire the 2 panels in parallel. Now I have a second set of these panels and so I essentially have 2 sets of parallel wired panels. My question is can I wire these 2 sets in series to achieve 24v without hurting anything? All the wiring diagrams that I see have the panels wired in series and THEN in parallel. In order to avoid having to hack up my existing factory wiring and ordering more connectors and more wire, I would like to simply hook these 2 strings up in series with each other.

Thanks in advance.

Panel specs?

CC Specs?

Without putting too much thought into it,
I imagine you would get the same current result either way, but with MC4 connectors is would be simpler to wire series first.

Edit: I put some thought into it... either 2x2 configuration you'll be needing these.

MC4_3927_8625.jpg

[jasonl549]

Panel specs?

CC Specs?

Without putting too much thought into it,
I imagine you would get the same current result either way, but with MC4 connectors is would be simpler to wire series first.

Edit: I put some thought into it... either 2x2 configuration you'll be needing these.

[ATTACH=CONFIG]4099[/ATTACH]

That is pretty much exactly what the panels came with. The output wires of each panel have a connector on them and they fit into a Y-connector like you showed in your picture and the combined (parallel) output goes on down into the charge controller. Yes, I could chop off the MC4 connectors on the output wires of each panel and rewire it but I would prefer not to.

The panels are DM Solar 145 watt panels (see below) and the charge controller is a Morningstar TS-45.

145w 0-3%
Cells by GinTech
VMP 18
IMP 8.05
ISC 8.95
VOC 21.6

[Sunking]

You just wire them in 2 x 2. Biggest issue is you have 12 volt battery panels which are very expensive and do not allow you to take efficiency advantage lower cost grid panels and higher voltage efficiency. It forces you to use a PWM controller and changes your 580 watt panel array into 380 watt array.

[Shockah]

You just wire them in 2 x 2. Biggest issue is you have 12 volt battery panels which are very expensive and do not allow you to take efficiency advantage lower cost grid panels and higher voltage efficiency. It forces you to use a PWM controller and changes your 560 watt panel array into 360 watt array.

Jason could use a TS-MPPT-45 with all the panels in series in one string, correct?
Then he could select 24volt output from the CC.
But damn, he already bought an ill-matched combo.

Coulda bought 2x275w grid-tie panels for le$$ than the 4xbattery panels... and use that savings to pay the higher cost of an mppt.

See Sunking... I'm paying attention to your posts

[Sunking]

Jason could use a TS-MPPT-45 with all the panels in series in one string, correct?

Easily. That would give him back a full 580 watts, and allow much less wire losses between panels and controller. Curious as to what size battery @ 24 volts?

[jasonl549]

Easily. That would give him back a full 580 watts, and allow much less wire losses between panels and controller. Curious as to what size battery @ 24 volts?

I know my panels aren't the perfect match for this new way of configuring things. There is a long story to this and I didn't have 24v in mind when I set out on this hobby/project. I got the panels ridiculously cheap ($200 for 2 with no shipping) so I think I am still in decent shape money-wise.

I have (4) Energizer GC2 6V batteries wired in series. They are $89 at Sam's Club and the specs are 20 hour rate: 225Ah at 75 amps: 110 minutes at 25 amps: 447 minutes and they are manufactured by Johnson Controls Mexico. I wanted to go with Trojan T-105RE but shipping was prohibitive and I didn't want to "learn" and make a mistake on an expensive battery.

[Sunking]

I know my panels aren't the perfect match for this new way of configuring things. There is a long story to this and I didn't have 24v in mind when I set out on this hobby/project. I got the panels ridiculously cheap ($200 for 2 with no shipping) so I think I am still in decent shape money-wise.

Are you sure it is a good deal. Grid Tied panels sell for less than $1/watt

[jasonl549]

Are you sure it is a good deal. Grid Tied panels sell for less than $1/watt

Where? Are you factoring in shipping? Freight shipping is insane. Hard to beat 290 watts for $200 with no shipping (brand new in box unopened from Craigslist). Even if you cut it in half (which is overkill for PWM losses) that is still $1.38 per watt.