Is this panel ok for this aio?

[wigglybuff]

I want to add solar and inverter to our small travel trailer. It only came prewired for solar with connection on the roof. I just want to add a small system so that we can run ac power (for micro, kettle, etc) at night while camping when we can't run the generator.

I am looking at the MPP 2724LV-MR for it's simplicity and good price along with a single 24v 100ah lifepo4 battery. My main question is if this single solar panel will be ok since I keep reading about starting voltage and the MPP unit. The MPP manual dictates it should be fine but online people say you need 40v min?

This is the solar panel I am thinking of purchasing. Going with a single one.

ZNShine Solar 405W Solar Panel 108 Cell ZXM7-SH108-405/M - A1 Solar Store

ZNShine Solar 405W Solar Panel 108 Cell ZXM7-SH108-405/M is the highest power solar module in residential US market. Look into detailed descriptions, ratings, reviews, pictures, and more. Look into detailed descriptions at A1 Solar Store

a1solarstore.com

Will it be ok?

 

[sunshine_eggo]

https://a1solarstore.com/index.php?dispatch=attachments.getfile&attachment_id=735

It will be marginal. STC Vmp of around 31.1V is on the low end for fully charging 24V batteries.

Considering the more "real world" parameters for NMOT where they factor in elevated cell temperatures: 31.1V drop s to 28.90V.

A 72 cell panel would be a better choice (Voc closer to 45-50V).

 

[wigglybuff]

https://a1solarstore.com/index.php?dispatch=attachments.getfile&attachment_id=735

It will be marginal. STC Vmp of around 31.1V is on the low end for fully charging 24V batteries.

Considering the more "real world" parameters for NMOT where they factor in elevated cell temperatures: 31.1V drop s to 28.90V.

A 72 cell panel would be a better choice (Voc closer to 45-50V).

Oh ok thanks. So what I want is a panel whose NMOT Voc parameter is over 40v?

 

[sunshine_eggo]

Oh ok thanks. So what I want is a panel whose NMOT Voc parameter is over 40v?

A 72 cell panel would be a better choice (Voc closer to 45-50V).

 

[wigglybuff]

Yes I get that but looking at 72 cell panels they are all too big for the space but I did find other panels that are smaller and still have a higher voc.

For example they have this one that has a 45v voc and it's much smaller so it will fit.

Meyer Burger 380W Solar Panel 120 Cell MB-380-HJT120-BB-T5 Clearance – A1SolarStore

Meyer Burger 380W Solar Panel 120 Cell MB-380-HJT120-BB-T5 at A1SolarStore

a1solarstore.com

So I can base my search on an nmot voc of 40v+ and be fine?

 

[sunshine_eggo]

Yes I get that but looking at 72 cell panels they are all too big for the space but I did find other panels that are smaller and still have a higher voc.

For example they have this one that has a 45v voc and it's much smaller so it will fit.

Meyer Burger 380W Solar Panel 120 Cell MB-380-HJT120-BB-T5 Clearance – A1SolarStore

Meyer Burger 380W Solar Panel 120 Cell MB-380-HJT120-BB-T5 at A1SolarStore

a1solarstore.com

So I can base my search on an nmot voc of 40v+ and be fine?

That looks like it will work. NMOT Vmp of about 36V.

 

[zanydroid]

54/108 , 60/120, and 72/144 are somewhat standardized form factors so that is another way to shop. The first number (the full cut cell count, which is also the same as the number of series cells in a half cut panel) will give roughly the VOC and VMP

There are differences of a few inches in each direction, and lower power could mean either slightly smaller version in that family, or lower efficiency bin from a particular assembly line.

For my rooftop install I mostly used smaller 144 cell modules (10% smaller than usual, more flexible in fitment) but also had a single 120 cell panel because I wanted to squeeze one more in on the highest producing side of the house