Solar panels and control boxes???

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Hi all,

Sorry if this has been done before, but I am considering fitting my boat with a 10 watt solar panel, just for trickle charging the barrery, now the way it was explained to me was......

A 10watt solar panel, can deliver about 3 amp hours a day, so would need a control box to prevent over charging the battery. What I want to know is, does this pan out?

The solar panel I am thinking of, is a semiflexible type that Seamark Nunn are selling for a little over £90.00, I am wanting to fit it to my hatch garage, and the semi flexible type will take the curve ok, also, they tell me that it can be walked on without damage?

Your thoughts would be appreciated.
 
It depends on the battery size (capacity in Ah) but you may not need a regulator at all. You will find some guidance on one of the solar panel websites, but I forget which one, but I think you will find that if you have 110Ah of battery you will not need one. If you only have a 60Ah battery then you probably will need one.
 
All solar panels have a low co-efficient of friction (they're slippery, and decks are not good safe places for them, as winch handles have an affinity for the bl**dy things /forums/images/graemlins/blush.gif ).

Prolly worth leaving it fixed when your'e not on the boat, and then removing it while you sail.
 
I believe they might be misleading you as to the amount of sun in the UK. I fitted a 30W panel originally and it was 3 days before I could detect that it was working. That was April. As for providing 21AH daily in the UK off 10W panel! I know summer days are long but they are limited by 24hours.

We now run with over 1/3kW of panels.

[ QUOTE ]
The new Spectra range of solar panels are ideal for maintaining and replacing natural discharge in 12V deep cycle batteries in leisure applications. In wintertime you can
avoid the trouble of taking batteries home for topping up by installing one of the Spectra range of 5Watt, 10Watt or 20Watt solar panels. In the UK we recommend a minimum
ratio of a 10W solar panel to a 100Ah battery, daily this would generate up to 3Ah. In summertime this increases up to a potential of 21Ah daily, typically enough for a summer weekend’s cruising needs for basic lighting etc. Most importantly you’ll arrive to a battery that is not flat!


[/ QUOTE ]
 
Thanks very much for your replies, I will have to do a bit more digging around I think? My boat is a Swift 18, and will not require an awful lot of power, it will be used for day sailing mostly. Probably go for an 85 amp hour battery and to be on the safe side, use a control box. My outboard auxilary does have a charging facility, but I think I would need to run it a hell of a lot to take advantage of that, not a favoured option :-)
 
I think the size of panel vs battery capacity means you probably dont need a regulator especially if the panel is laid flat on deck as then you will lose output because it is not pointing at the sun.

I find without a regulator, a 20W panel with a diode splitter from the panel, and 2x75AH batteries the effect of the solar cell has really prolonged the battery life by preventing the batteries remaining flat for long.
 
[ QUOTE ]
My boat is a Swift 18

[/ QUOTE ] You will not really need a 10 watt panel. I have a 5 watt panel and I did have a 45 Ah leisure battery. That was quite adequate even using the autohelm for much of the time. I now have a bigger battery (60 Ah I think) as the little one is no longer available.

If you have the space to fit a 10 watt panel then do so but if you are fitting an 85 Ah battery then definitely fit a regulator.

I notice Barden are including a regulator in the price of (some of) their flexible panels.

BTW make sure you fit a fuse, as close to the battery as possible, in the solar panel circuit.

Don't count on getting any really useful amount of power from the charging facility on an outboard. At least not unless you run it at a fairly high speed for a fair length of time.
 
No one has mentioned the fact that solar panels are rated when pointing at the sun. ie about 40 degrees to horizontal and pointing South. If the panel is flat and if the boat is on a swing mooring then you will only get perhaps half of the max power.

I would go on a limb and say that 10 watts is safe without a reg in UK with a flat mounted panel with almost any battery except the small SLA batteries.

After many replacement panelsthat were deck mounted (over 25 years) I have settled on a panel attached to the top of the boom cover by bungee cords and a power cord pugged in o the switch panel just inside the hatch. ie it gets removed every time I sail.

Anyway if you feel like importing a panel have a look at
http://www.whitworths.com.au they have BP panels which are very good .
http://www.oatleyelectronics.com they have possibly Chinese panels but at 2.5 oz dollars to the squid they are cheap. good luck olewill
 
[ QUOTE ]
I have settled on a panel attached to the top of the boom ....... it gets removed every time I sail.


[/ QUOTE ] In the solent area it would probably get removed very quickly when you weren't sailing!
 
Solar panels are rated at 'lad" conditions and are affected hughly by how far north or south of the equator they are. in the Solent your panel is likely to produce about 3/4 to 1/2 of the stated output as you are up along way and exposed to usable light for a lot less hours than a manufacturer will have you believe.
Your set up will work fine 360 days a year in the UK , but as good weather has been in short supply this year there is nout to worry about . On the few days that you mite have a problem there will be enough worning to go and disconnect it if you dont go to the expense of controller box and sudry do-hickys.
 
[ QUOTE ]
Solar panels are rated at 'lad" conditions and are affected hughly by how far north or south of the equator they are. in the Solent your panel is likely to produce about 3/4 to 1/2 of the stated output as you are up along way and exposed to usable light for a lot less hours than a manufacturer will have you believe.
Your set up will work fine 360 days a year in the UK , but as good weather has been in short supply this year there is nout to worry about . On the few days that you mite have a problem there will be enough worning to go and disconnect it if you dont go to the expense of controller box and sudry do-hickys.

[/ QUOTE ]

Once again thanks all for your input, Mandlmaunder.......what's a do-hicky, and how much power does it put out??? /forums/images/graemlins/grin.gif
 
I would go out on a limb and say this solar panel will only produce 1 amp at best as a rule of thumb the degrees you are is the direction a solar panel should be pointed if not at 90 degrees
 
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