Solar panel output.

[Rappey]

At 5 years old my 160w solar panel is dead as it has zero output. Dont understand how that happens but i guess thats how it is.
Had to find a replacement that could be no longer than the original. Not the easiest searching by size rather than power.
Found a panel on ebay that fits and is only 5% bigger but its now 300w . Amazing that 5 years later im nearly getting twice the power at less money..
My 160w (£165) was one of the more expensive panels at the time as it had slightly better output that its competitors. My 300w (£115) is the cheapest i could find.

 

[Chiara’s slave]

From the size of it, I’d call bull**** on the spec.

 

[PaulRainbow]

From the size of it, I’d call bull**** on the spec.

Looks more like 100w

 

[PaulRainbow]

At 5 years old my 160w solar panel is dead as it has zero output. Dont understand how that happens but i guess thats how it is.
Had to find a replacement that could be no longer than the original. Not the easiest searching by size rather than power.
Found a panel on ebay that fits and is only 5% bigger but its now 300w . Amazing that 5 years later im nearly getting twice the power at less money..
My 160w (£165) was one of the more expensive panels at the time as it had slightly better output that its competitors. My 300w (£115) is the cheapest i could find.

Do you have a link to the Ebay panel ?

 

[[70521]]

Where did you measure the output from?

 

[Rappey]

I was also Very scepticle as the ebay ad makes it look amazing . I did a short circuit current test one evening and measured 15 amps while the panel was about 2v lower than its max open circuit voltage as it was around 7pm.
By 4.30 this afternoon it was fitted to my boat, plugged it in and seeing up to 12 amps into the battery.. thats virtually double of the expired 160w.
At 1354x767 im impressed so far.
Below is the label on old and new, plus the link for paul .
300W Watt 12V Mono Solar Panel Caravan RV Off Gird Battery Charging Power Boat | eBay UK

 

[Chiara’s slave]

Looks more like 100w

My ebay 100w semi flex panels are much that size. Efficiencies have improved about 20% in the last decade, I think? But claims like that, it cannot be true.
My home panels are 600w, and 2340 x 1134mm, 24.1% efficient.

 

[Rappey]

But claims like that, it cannot be true.

So im a liar ? Thanks...

 

[fredrussell]

So im a liar ? Thanks...

I assume he means the eBay claims.

 

[lustyd]

By 4.30 this afternoon it was fitted to my boat, plugged it in and seeing up to 12 amps into the battery.

That’s about 150W for a 12V system? Pretty good for the size and certainly reasonable for the money.

 

[PaulRainbow]

I was also Very scepticle as the ebay ad makes it look amazing . I did a short circuit current test one evening and measured 15 amps while the panel was about 2v lower than its max open circuit voltage as it was around 7pm.
By 4.30 this afternoon it was fitted to my boat, plugged it in and seeing up to 12 amps into the battery.. thats virtually double of the expired 160w.
At 1354x767 im impressed so far.
Below is the label on old and new, plus the link for paul .
300W Watt 12V Mono Solar Panel Caravan RV Off Gird Battery Charging Power Boat | eBay UK

Given the size, it's about 200W max, about right for the price you paid.

 

[Chiara’s slave]

So im a liar ? Thanks...

You daft b*, the Ebay seller not you! You see that a lot on ebay. Go by the size, not so much the claimed output.

 

[William_H]

I only have data on domestic 40v panels. It would appear that over recent years they have indeed doubled the power output for a given physical size. Plus becoming much cheaper. Unfortunately for a boat physical size is critical but I would advocate buying domestic panels if you can fit them on board. Typically about 1.8m by .8m so quite big. (from the land of the domestic PVs where 40% of households have PV panels.) ol'will

 

[Rum Run]

That would be 300 eBay watts not 300 SI unit Watts.
Just like the 300dB car horn I bought from there recently is not 300dB in reality.

 

[Chiara’s slave]

That would be 300 eBay watts not 300 SI unit Watts.
Just like the 300dB car horn I bought recently is not 300dB in reality.

In the latter case, just as well I think the yanks experimented with that sort of thing back in the 1960s but it was deemed as dangerous to friend as foe.

 

[Rappey]

A 200w renogy panel on ebay has a listed short circuit current of 11.05A. I measured 15A short circuit on mine and 12A through a charge controller both in late afternoon so it cant be only 200w ?

 

[shanemax]

So im a liar ? Thanks...

Dont take any notice.......They are all jealous of your 12 amps. Good result.

 

[lustyd]

A 200w renogy panel on ebay has a listed short circuit current of 11.05A. I measured 15A short circuit on mine and 12A through a charge controller both in late afternoon so it cant be only 200w ?

Amps depend on voltage, so that’s not a sensible way to compare. You need to measure in Watts, hence my post above where I calculated your Watts to be about 150ish based on 12A at 13V (assuming a 12V battery system). You were measuring output Amps to the battery while they were quoting input amps from the panel, which will be probably 18V

 

[PaulRainbow]

A 200w renogy panel on ebay has a listed short circuit current of 11.05A. I measured 15A short circuit on mine and 12A through a charge controller both in late afternoon so it cant be only 200w ?

The surface area of the panel equates to that of a 200W panel, there isn't a 300W panel that small.

 

[Rum Run]

In the latter case, just as well I think the yanks experimented with that sort of thing back in the 1960s but it was deemed as dangerous to friend as foe.

Indeed, though it would be fun to test on some of the less considerate road users around.