ghostlymoron
Well-Known Member
Where is the best place to get solar panels at reasonable cost. I'm looking for a 20w panel pref capable of withstanding occasional foot traffic. Do I need a regulator?
Cheap solar
- Thread starter ghostlymoron
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VicS
Well-Known Member
Don't buy a cheap one if you want it to withstand life permanently on deck!
My new one is a Specrta (I think). Came from Sea Teach in Emsworth anyway, being the local chandlers to the boat.
One rule of thumb is less than 1 watt of panel per 10 amp hours of battery capacity does not need a regulator but advisable with panels over 10 watt anyway regardless. So maybe not absolutely vital, but advisable, if your battery is over 200Ah
Someone posted a more complex rule though about 10days or so ago. a search might find it.
There are different types of regulator to consider too, from simple ones that simply disconnect to shunt ones that dump the excess into a shunt, to pulse width modulated (PWM), to maximum power point tracking (MPPT ). The latter will convert the power usually wasted, because the battery charges at 14 volts and the panel max output is at about 17 volts into extra amps at the lower voltage. I believe they may also boost the volts at low light levels but not so sure about that. .... dont really understand it all but recently read about it!
Explanation of MPPT
My new one is a Specrta (I think). Came from Sea Teach in Emsworth anyway, being the local chandlers to the boat.
One rule of thumb is less than 1 watt of panel per 10 amp hours of battery capacity does not need a regulator but advisable with panels over 10 watt anyway regardless. So maybe not absolutely vital, but advisable, if your battery is over 200Ah
Someone posted a more complex rule though about 10days or so ago. a search might find it.
There are different types of regulator to consider too, from simple ones that simply disconnect to shunt ones that dump the excess into a shunt, to pulse width modulated (PWM), to maximum power point tracking (MPPT ). The latter will convert the power usually wasted, because the battery charges at 14 volts and the panel max output is at about 17 volts into extra amps at the lower voltage. I believe they may also boost the volts at low light levels but not so sure about that. .... dont really understand it all but recently read about it!
Explanation of MPPT
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seanfoster
Well-Known Member
I keep hearing various rumors of Chinese manufacturers about to flood the market with reasonable quality cheap solar panels, nothing ever seems to come to fruition, does anyone know anything about these?
dmmbruce
Well-Known Member
I suggest you do a search of previous posts on this, there has been a lot of information.
The gist of it is that 85% of all solar panels are made in China. Very many are sold via ebay. It is suggested that it is a good idea to buy through a uk supplier so that you have buyer protection rather than going direct for the cheaper ones and possibly getting the seconds that are being sold off!
Hope that helps.
Mike
agent leman
Member
Just seen at Maplin today - 60 watt inclusive of regulator £199! I didn't have the time to pull one out of a box and inspect the quality but definitely will be going back during the week for a thorough eaxmination. Got to be a catch........
VicS
Well-Known Member
Looked at Maplins ones before I bought mine. I did take one out of the box ... put it back again and went to Sea Teach. Paid a good bit more too.
fireball
Well-Known Member
Like Vic we went to SeaTeach - we've only got a 20w (or is it 30w) panel - had it on the boat attached to the twin lesiure batteries (280AH when new) and not bothered with a regulartor - absolutely fine and has kept the batteries charged nicely. It wasn't hugely expensive (£130 ish) but is semi flexible and is now permamently attached to the coach roof...
V1701
Well-Known Member
From reading previous posts you'll probably find these are old technology (this doesn't mean bad per se) and very heavy in comparison to newer solar panels...