Solar Panel

[pgtips]

I see that Maplin are knocking out a cheap (£9.99) 12 volt battery trickle charger and wondered if anyone has any views on how effective these are likely to be?

I have a 24ft yacht with a 1GM Yanmar in with very little in the way of electrics running from the boat (depth sounder & lighting basically) but as the boat is only being used couple of times a month would something like this be sufficient to keep the battery topped up?

Appreciate you get what you pay for, so perhaps worth just spending a tenner to see how well it works....or doesn't??

 

[Danny]

I would think it would be enough to keep the battery topped up and in good condition - so long as it's well charged when you leave the boat. One advantage with such a small panel is that you won't get a charging current in excess of a few tens of milliamps - so you're unlikely to damage the battery through overcharging. This can happen with larger panels if they are unregulated.

 

[BAtoo]

Its not waterproof........ /forums/images/graemlins/frown.gif

 

[mikejames]

I had a 5 watt panel and this would leave the batteries on my GK24 in a good state of charge after a couple of weeks.

It was good enough that I didnt bother with shore power even though I kept the boat in a marina at the time.

The Maplins £9.99 panel says it is 1.5 watts. Thats 125mA in bright sunlight or about half that in the real world of britain. Or about the leakage of a battery.

Buy three or four and you will definitely recharge the battery as well as keeping it topped up. Fit separate series diodes to each panel and then you will not suffer from shadowing - if only one is shadowed the others will keep on going

Waterproof them as well ... they are intended for use inside on a car dashboard so you can expect them to rot away in weeks on a boat. Dont forget cooling - hot panels produce less power so too much enclosure can reduce performance though.

My Solarex panel rotted after about 10 years and needed a missing wire reconnected , as it had electrolysed away when frost lifted up the backing sheet on the panel.

Go for it ,
(although I managed to buy a new LC Solar panel for £120 which puts out 18 watts at Beaulieu last April. 12 times the price and 12 times the performance )
If the Maplin charger were not on special offer its not actually very good value.

 

[Danny]

[ QUOTE ]
Thats 125mA in bright sunlight or about half that in the real world of britain. Or about the leakage of a battery.


[/ QUOTE ] A bit pessimistic! That would mean that a disconnected, fully charged 100AH battery would COMPLETELY discharge in about a month. I don't buy expensive batteries but they perform a lot better than that.
[ QUOTE ]
Fit separate series diodes to each panel and then you will not suffer from shadowing - if only one is shadowed the others will keep on going

[/ QUOTE ] Good point, but I think the series diode already fitted on the Maplin panel would serve the same purpose if you parallelled up more than one panel.

 

[reginaldon]

Picked up a 9W panel on Ebay around 28 GBP - does all I need very quickly, no more carrying a v. heavy battery across the mud,

 

[William_H]

Aws already stated pounds equals size equals amps. This may be a reasonable offer for a few milliamps. However if you have a decent generator on your engine then a few minutes running will replace what your small solar panel would provide so it is perhaps not necessary. On the other hand I have a 2 watt panel which actually provides all my poower and recharges a 14AH nicad over a few weeks so for my meagre current requirements it does the job. (did I mention lat 32S long 115 east) ie lots more sun. regards olewill

 

[pgtips]

Thanks for all the replies. As usual with the forum lots of good advice.

I appreciate that the panel isn't waterproof, but the size of it is just about right to fit in one of the boat windows which gets sun (or light!?) most of the day so I should be able to leave it inside.

If I decide to go down this route I'll let you know how well it works........or otherwise!?

Thanks again

Paul

 

[xeitosaphil]

Just one point ,if you intend to put the panel in a window of the boat I can't see you actually getting a lot from it anyway.All solar panels require light to hit them full on . Basically the suns rays need to hit the panel at right angles over a long period of sunlight to get any sort of charge,. Say you fit the panel in your port/starboard side window which I assume is at approx 80degrees to the deck the sun reaches its maximum output at miday which means unless you are actually tracking the sun from sunrise to sunset you are only going to get about 5 hours at most this time of the year and that depends on if its a sunny day. Most solar panels are fitted outside because of there available access to the sun which needs to be the maximum hours available, to acheive the best results.

I wish you luck with yours, but don't hold out much hope of it producing much charge.

I have a 20w Solarex and regulator about 16"x 16" which keeps my battery charged all year round but its on an adjustable bracket / aft mounted pole, and I change its orientation to the sun every month, luckily my fore and aft mooring faces aprox due south

 

[pgtips]

Good point and hadn't thought about that!?

Guess if I want to go down this route will be best spending a bit more and fitting something outside.

With this in mind, does anyone know how well the flexible panels work that can be wrapped around the sail & boom?

Appreciate that orientation of boat still important, but I'm quite lucky in this respect with mooring position.

 

[samwise]

Flexi panels are great. Our 30w Unisolar panel has been a worthwhile buy. Talk to Barden. Only problem is wher to park the thing when it is not in use. I am reluctant to leave it in place where security might be suspect.

 

[pathunt]

I have one of those panels that VW use to keep batteries topped up on new vehicles and find there is hardly any difference in output if its outside or inside, these are designed to fit inside on the windowscreen on VW's. ( or I could have a dicky multimeter!!)