Solar Panel solely for charging batteries off grid.

[LadyG]

I bought larger panels when I moved out of the marina, as cc livesboard, using the existing frame. With more thought I'd have gone for the @Blackrose solution, making sure they looked good, and were the most efficient panels per square metre.

I sold the original solar kit to a couple in the boatyard (for £65) who were en route to France on a cruiser, picking up work as they went, quite an adventure....

Buy an extra battery, ban hairdryers and curling tongs....

[robtheplod]

1 hour ago, Jen-in-Wellies said:

Possibly a left over from the days when not meeting ventilation area was a BSS fail for private boats, rather than an advisory, as it is now.

I'm guessing the air gap is still there so would this be impacted?

1 hour ago, Jen-in-Wellies said:

Possibly a left over from the days when not meeting ventilation area was a BSS fail for private boats, rather than an advisory, as it is now.

I'm guessing the air gap is still there so would this be impacted?

[Jen-in-Wellies]

1 minute ago, robtheplod said:

I'm guessing the air gap is still there so would this be impacted?

I'm guessing the air gap is still there so would this be impacted?

In that case, no. I made an assumption that you'd effectively sealed the ventilation hole, but on closer examination, the panel acts as a rain shield, like the cap of a mushroom vent. A good solution.

[Tony Brooks]

1 minute ago, robtheplod said:

I'm guessing the air gap is still there so would this be impacted?

I'm guessing the air gap is still there so would this be impacted?

 

Not sure what you think may be impacted, but as far as the BSS and examiners who stick to the rules then doing as suggested with the panels would have no impact. As far as keeping the ventilation is concerned, again as long as there is greater than (say) 12mm gap between the top of any vent aperture and the underside of the panel then I can't see ventilation being impacted an rain ingress as suffered by many mushroom vents should be stopped.

[robtheplod]

plus depending on panel you might get a bit more light in as well!!

[blackrose]

12 hours ago, Jen-in-Wellies said:

In that case, no. I made an assumption that you'd effectively sealed the ventilation hole, but on closer examination, the panel acts as a rain shield, like the cap of a mushroom vent. A good solution.

 

Yes all I've done is remove the brass mushroom vent. The hole is still there so the panel acts as the cover instead. I probably confused you by mentioning sealant. I just put a thick bead of PU sealant around the perimeter of the hole to act as a lip or rim, but it's probably unnecessary.

[Jess--]

We used a 240w semi-flexible panel as pictured below which kept up with most of our usage (pic is after the panel had been in place for 5 years)

Semi flexible panels will not last as long as solid ones, the plastic coating degrades over time (probably UV damage) Based on when a friends identical panel failed I would expect 6-7 years lifespan.

 

[blackrose]

This cool sunny weather is great for charging. I thought I may as well put the 1kW mains immersion heater on for an hour. Got about 25A coming from the batteries.

 

My 2 panels are 41.3v each connected in series, so am I right in thinking they're working at about 95% efficiency?

 

Edited May 5 by blackrose

[Sailbadthesinner]

I doubt it. Most solar panels are about 20% efficient.

Strangely, according to that display your solar controller is putting 750W in to your batteries yet getting only 720W from the panels. Controller must be 104% efficient!

Hence the smiley face?

 

[Chewbacka]

To calculate percentage of useable power compared to rated power you need to look (probably) on the back of the panels to see what the rated power is for each panel, add the numbers together to get total rated power then compare that to the power going into the solar controller.  Power in watts being supply volts multiplied by supply amps.  In you photo above that would be 79.1x9.1