Victron 100/30 or 100/50

[spielen]

Planning my solar setup for our TT and I have 2 Rich Solar 200w 12v panels on the way. Trying to decide if the 100/30 will be fine knowing that I will miss out on 3a of charging at low temp per the victron excel calculator. The panels will be flat mounted on top of the RV, so I doubt I will get the full 400w anyway. Planning to run them in parallel. Specs for the panels are:

• Maximum Power(Pmax): 200W
• Maximum Power Voltage(Vmp): 20.4V
• Maximum Power Current(Imp): 9.80A
• Open Circuit Voltage(Voc): 24.3V
• Short Circuit Current(Isc): 10.2A
• Maximum System Voltage(Vmax): 1000VDC
• Temperature Range: -40°C ~ 90°C
• Max Series Fuse Rating: 15A
• Weight: 26.5 lbs
• Dimensions: 58.7 x 26.8 x 1.4 in

The specs say the 100/30 is good for 440w and Will's site says it is good for 440w as well, just want to double check before I order.

TIA

 

[GSXR1000]

I would go with the 50 so you can go with 4 panels later on.... I have 100/50 with 2x 305 watt panel on my 26ft travel trailer... barely big enough .. just installed my 560ah battery

 

[Hedges]

The charge controller delivers amps not watts, so max 360W into 12V, 450W into 15V.
The voltage of your battery will determine how much power you get.

As you note, flat on the roof won't get max power except when the sun is directly overhead.
Besides, a "200W" panel will typically only deliver 170W under typical conditions as opposed to standard test at 25 degrees C without time for sun to heat it up.

If you carry a portable panel to be tilted toward the sun, that might make considerably more some seasons.
It could have its own charge controller, or be connected to same controller (assuming all panels are in parallel.)

But like GSXR says, always good to oversize if you can afford it.

 

[Bud Martin]

I would go with the 50 so you can go with 4 panels later on.... I have 100/50 with 2x 305 watt panel on my 26ft travel trailer... barely big enough .. just installed my 560ah battery

+1

 

[spielen]

I would go with the 50 so you can go with 4 panels later on.... I have 100/50 with 2x 305 watt panel on my 26ft travel trailer... barely big enough .. just installed my 560ah battery

I can't fit and more on my roof. It is a R-Pod, so space in limited.

If you carry a portable panel to be tilted toward the sun, that might make considerably more some seasons.
It could have its own charge controller, or be connected to same controller (assuming all panels are in parallel.)

I plan to add a second controller in the future for a DIY 200w briefcase for when we camp in the shade. Think if I did a 3rd 200w panel, even the 100/50 would be limited.

I'll be using a 206ah SOK.

 

[Hedges]

3 x 200W = 600W
12V x 50A = 600W
Looks sufficient to me.

If battery is lower than 12V at the moment, then charge controller will deliver less. At perhaps 10V minimum (where you shouldn't be operating the battery), 10V x 50A = 500W.
Panels will usually put out less than 600W. Two aimed at the sky and one aimed at a different angle will be less than 600W.

You'll have a pretty hard time getting the 50A charge controller to clip with those panels.

Redundant hardware does let things keep working if one fails, so that's a plus to having separate charge controller.
Do you also have a way to charge from the tow vehicle?

 

[spielen]

Do you also have a way to charge from the tow vehicle?

Was planning to disable tow vehicle charging for now. Maybe in the future I'll add it.

 

[spielen]

One other question, is this going to be too much current for MC4 connectors. Say I decide to go with the 100/50, parallel connection on the roof with MC4 then another parallel connection inside where the side port ties in with MC4. Or maybe MC4 on the roof, then a combiner box inside.

Was just thinking that if I do two 100 watt panels for the briefcase, it might be better to use a different SCC since the panels wouldn't have the same specs.

 

[GSXR1000]

One other question, is this going to be too much current for MC4 connectors. Say I decide to go with the 100/50, parallel connection on the roof with MC4 then another parallel connection inside where the side port ties in with MC4. Or maybe MC4 on the roof, then a combiner box inside.

Was just thinking that if I do two 100 watt panels for the briefcase, it might be better to use a different SCC since the panels wouldn't have the same specs.

why not put the panels in series? I would prolly go with 100/30 (will push 380w) and save the $100... didn't know you had zero room for expansion...
on your ground array use a separate SCC

 

[chrisski]

100/30 is definitely a more ratonal choice, but why not spend the extra $100 and get the 100/50.

I bought the 100/50 for 600 watts of rooftop panels and have never seen near 30 amp output with a flat roof orientation and shading on some of the panels. If you’re dealing with an RV roof, if you don’t remove the air conditioners and don’t put the panels above the vents, you are going to deal with shading. Max output I’ve seen on my roof from that back is about 20 to 25 amps, and reading panel labels I should see 36. I could get more amps by going to the roof and raising the panels, but who wants to spend 1 hour on the roof to put them up and one hour on the roof to take tilt them down on each two day trip?

I also wanted to put more panels up top, but when I started putting cardboard cutouts, there was no more room for like sized panels, maybe 200 watts more. I ended up going with another charge controller and adding 350 watts of panels to the roof,

 

[rickst29]

One other question, is this going to be too much current for MC4 connectors. Say I decide to go with the 100/50, parallel connection on the roof with MC4 then another parallel connection inside where the side port ties in with MC4. Or maybe MC4 on the roof, then a combiner box inside.

Was just thinking that if I do two 100 watt panels for the briefcase, it might be better to use a different SCC since the panels wouldn't have the same specs.

Yes, you will want a different SCC for your on-the-ground pair. Some 'briefcase' products already have an SCC inside.

But I want you to wire those two panels in Series: Even with the batteries under the rear bed (???), your round-trip distance on the Solar wires is probably going to exceed 15 feet. I'm good with pushing those Victrons up to about 80% of their Voltage ratings - so you can wire the rooftop panels in Series. V(oc) for both panels (in Series) would be slightly less than 50 volts. Maximum current will be cut in half, back to 9.8A or less. Even on your very short distance, that will significantly reduce "Voltage drop" power loss within the wires, and your MC4 connectors will far more comfortable.

I personally have about '500W' of Solar panels on a flat roof, and I have never seen more than 440W - at high altitude on a perfect and cool day, at exactly 1pm. (Thy're all in Series, BTW ... but I have a 150V controller.) You will never be getting 2x200 = 400 watts from the rooftop panels in the real world. I'll go ahead and SWAG 360 watts, at best.

 

[GSXR1000]

I get over 40 amps on my 710w

 

[Hedges]

One other question, is this going to be too much current for MC4 connectors. Say I decide to go with the 100/50, parallel connection on the roof with MC4 then another parallel connection inside where the side port ties in with MC4. Or maybe MC4 on the roof, then a combiner box inside.

why not put the panels in series?

With two panels in series or parallel, current won't be too much for MC4.

A third panel in parallel might be depending on the connector, but only if current from all three goes through it. A "Y" on the roof could combine two, and a "Y" at the charge controller could combine that with a third panel. If the output MC4 was cut off and 8 awg wire from the "Y" went to charge controller screw terminals, that would take care of it.

(A 10 awg wire with 40A ampacity and 30A current limit according to NEC would function with three, 9A panels in parallel but not meet codes used for buildings. MC4 connectors are questionable above 30A, might be OK if both halves of sufficient rating and quality. So I figure an 8 awg "Y" with the one connector that would carry 3x PV current would be a way to go.)

I favor series connection of panels, even/especially if they will get partial shading. Just have them all oriented the same.

If you can hinge the panels and have a way to tilt and secure them quickly, you'll get much more power. Is there room on the side to hinge a panel and tilt it out as an awning? (but parking in the shade and placing a portable panel in the sun would be better.)

 

[GSXR1000]

I hit 46.4 amps yesterday