Hard data - Sunpower 360w Performance

[arsenelupiga]

do you have any hard data to support factory claims about low light / cloudy / overcast performance ?

Sunny days are never a problem so max output is hardly important.

[john61ct]

If you feel that way overpanel, Victron 75/15 1:1 with the OP panel, under $100, should get near-constant 220-240W output 80% of daylight hours even in the PNW, unshaded of course.

[mitiempo]

Originally Posted by john61ct

If you feel that way overpanel, Victron 75/15 1:1 with the OP panel, under $100, should get near-constant 220-240W output 80% of daylight hours even in the PNW, unshaded of course.

15 amps at best. Good controller but leaves quite a bit on the table.

[john61ct]

We've beat that dead horse argument enough. I was specifically responding to:
> low light / cloudy / overcast performance ?
> Sunny days are never a problem so max output is hardly important.

[mitiempo]

Originally Posted by john61ct

We've beat that dead horse argument enough. I was specifically responding to:
> low light / cloudy / overcast performance ?
> Sunny days are never a problem so max output is hardly important.

It's easy to over-panel and max the controller on low light days. There are days though with mixed sun and cloud. During the cloudy periods there will be less output, maybe none. It makes sense to me to maximize the output during the sunny periods when it is possible. On a varying cloud day the sun will come out with cooler panels which will give maximum output, maybe even over rating.

Why not get the most from the panel that you can at all times?

[skipgundlach]

Originally Posted by Captain Bill

I would worry about my batteries if what I'm seeing here is typical. There are no days when the batteries even get into absorption, let alone to full charge. This is slow death for AGMs. I notice my lifelines starting to loose capacity after just a couple of weeks of not getting them to 100%. If you've been doing this for a while without capacity loss, you should tell us what brand of AGMs you are using.

Still no report; sorry - but...

The professional analysis of my recent premature death of our L16 FLA battery set was chronic undercharging. Attempts at resuscitation by going on the dock and doing deep cycle, full charge, equalize, rinse/repeat were unsuccessful for 2 of the 4 batteries; we now have 4x Trojan L16HAC for a nominal house bank of 870AH.

We monitor that, now, with a Balmar Smartgauge, rather than an amp counter, and our solar array upgrade (essentially the same footprint for 720w vs the prior 370w) has literally changed our lives.

However, that change is carefully monitored as well as blessedly silent (Honda doesn't run much), and if it gets more than two days without a full 100% rating, we supplement the solar with the Honda in the morning to make sure it gets there.

If you have an accurate measuring device, as it seems you do, you need to bring your batteries to C 100 (full charge) at least once a week, and if that's all the 'often' it happens, equalize once a month, or you'll have the same short-life experience we did.

Our controller also has an equalize setting, so we use that to do so on the infrequent times we use it.

[john61ct]

Only once a week will result in very reduced lifetime.

Skip's morning genny run is a great gap fill if you can't increase solar, or for overcast conditions.

High-CAR chemistry and a high-amp shore charger, maybe fully loading the genny will help reduce runtime: take running loads into account in your sizing!

Getting the holding plate and laptops charged, dishes or laundry done etc can just become a near-daily ritual, often just an hour's enough.

But before the solar day starts is best.