Nasa Solar panels

[jack_tar]

I am looking for a small solar panel to top up a 100 AH battery, I seem to remember that the Nasa panels did well in the pbo tests

What is the opinion of the forum? any comments or recomendations welcome Also links to information and place to purchace,

Do you think i would need a charge regulator for this combination?

[ghostlymoron]

I don't know about NASA panels but there's a good selection of panels on ebay apparently. The need for a regulator is dealt with in http://www.ybw.com/forums/showthread...olar+regulator. My personal opinion is that semi-flexible panels are most suitable for boat use due to their better performance in semi-shaded conditions and that a regulator should be installed. These range from cheap on/off types at £10 to more efficient MPPT types at nearer £100 - you pays your money .......... I bought my 2 panels from SeaTeach and they performed very well. I wouldn't be so sure about Chinese ebay units. They are a good investment when you consider all the free power you get from them over the years although the output does drop 5%ish each year I understand.
There is a formula for calculating the size of panel against battery capacity but I don't know it all I can say is that a 20w panel performed well enough with a 110ah battery.

[VicS]

I am looking for a small solar panel to top up a 100 AH battery, I seem to remember that the Nasa panels did well in the pbo tests

What is the opinion of the forum? any comments or recomendations welcome Also links to information and place to purchace,

Do you think i would need a charge regulator for this combination?

I dont suppose any forumite has done a proper long term scientific test on the Nasa panels (or any other) to be able to make an informed comment ... very probably pbo have not either so their comments may be of very little real value.

There are plenty of panels about in that price range. You makes your choice and pays your money.

Alternatively you give a cheap ebay offering a try.

(My 5 watt panel came from Seateach. If I am still here and in the unlikely event that I still own the boat in 10 years time I will tell you how well it has done.)

A common rue of thumb regarding a regulator is that your do do not need one if the power of the panel is less than the ratio of 1 watt per 10Ah of battery capacity. Except that one is recommended anyway for panels over 10watts.
So you do not need a regulator for the 10 watt panel but you will for the 20 watt panel.

You have choice to make regarding regulator. A basic one that simply disconnects the panel when the battery is charged. A "Pulse width modulated" one which controls the rate of charge, or a "maximum power point tracking" one which by electronic jiggery pokery extracts the maximum power from the solar panel.

[jack_tar]

thanks for the advice guys To be honest nothing i did not know but reasuring to hear it reflected back.

have looked at the panels on e bay and it seems that I can get a 20 w and a charge regulator for around 50 Quid which seems like a good deal. but as you say both say you gets what you pays for to some extent.

Will continue to looka around and cabvas opinion

Cheers

[William_H]

It seems to me that for a smallish boat the location and mounting of the panel will dictate the physical size of panel you can easily fit. This then along with budget dictates the wattage you buy which dictates the need for a regulator. I would tend to go for the 10w no regulator cheapest. or that just me? olewill