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Post by ross on Aug 30, 2013 20:22:53 GMT
Hi All. Installed 100w panel & controller earlier this year & worked a treat mainly keeping elec going whilst w/c in France for summer. So over the next few months the van won't be getting so much use & I'm wondering what's best to do in order to look after panels (longevity etc) & leisure battery. Controller unit will prevent over charging, but I could disconnect the panel, remove it (screwed onto brackets) or cover it over with light proof material. Should I be concerned? Don't want to unnecessarily damage leisure battery by not allowing it to sufficiently rest, & similarly get the most out of the panels. Interested in your thoughts please! BTW I've a DIY Master conversion, inspired in places by Firefox via Youtube (many thanks!)
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Post by Firefox on Aug 31, 2013 1:45:19 GMT
Thanks And welcome to the forum ! If you have a good enough controller it should be OK. The first year I had a cheap £20 one from maplins and I saw on my volt meter it was fluctuating from float charge of about 13.3V to nearly 16v and back down when the sun was bright. This could have cooked the batteries. In practice I used to switch it off on bright days. The new controller is one of those MPPT things. It cost about £70 but is much better at keeping the batteries at about 13v when they are charged even when the sun is bright. It has readouts of voltage, current, watts, state of charge etc, so you can see exactly what is going on. I have no problem leaving this one connected all the time.
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Post by ross on Aug 31, 2013 9:31:12 GMT
Got it thanks! So i've got a good controller but it's PWM type, not MPPT. looks like the MPPT controller will cost more, but more vfm in the long term. Check out this useful comparison vid: www.youtube.com/watch?v=QpL4RR0_QyMSo in the short term I'll probably disconnect for the colder weather I was looking at getting a small heater - bit like frost protection for greenhouses - to run directly from 12v. However I've only found the small fan types, with poor reviews. Plus elec is wasted on the fan. Anyone know of any suitable heaters to fit the bill? Great forum thanks - glad I've stumbled across it!
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Post by Firefox on Aug 31, 2013 11:34:30 GMT
So long as it is a good controller I think you'll be OK. If it doesn't give you the voltage on the controller, you can always attach a voltmeter across the battery and see how it performs in bright sunlight when the battery is charged and make sure there is not too much harmful pulsing. The output from some panels can be 30 volts so the controllers have quite a bit to handle at times. From memory, all the MPPT does is help maximise power output under certain conditions, but I'm not sure it makes much difference with UK type sun!! Thanks for joining, and hope you enjoy the forum
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Post by Pollik on Aug 31, 2013 11:50:15 GMT
FWIW, I have panels on the top of my van. I don't do anything with mine over winter...when I came out after all that snow, I found my batteries totally flat....combination of snow blocking light, winter not producing much charge and, I assume, something left on.
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Post by brewkit on Sept 1, 2013 13:02:50 GMT
I put 3 small volunteers on the dash, shows how much juice in each battery. The panel sits on the roof 24/7 not had any issues so far.
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Post by brewkit on Sept 1, 2013 13:06:33 GMT
Don't just love predictive spelling, , voltmeters cost me a coupla quid each, wired to each battery.
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Post by X on Sept 1, 2013 13:47:01 GMT
I put 3 small volunteers on the dash, shows how much juice in each battery. The panel sits on the roof 24/7 not had any issues so far. I had visions of small children wired into your solar panels ! Now you gone and spoilt it !
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Post by tommy on Sept 10, 2013 18:34:58 GMT
I have a 30a toggle switch to break the +ve solar pannel wire and issolate, but its only there so I can turn the power off from the pannel when I' m resetting an amp hour in/out meter that must have no voltage to do so.
As for the £70 mppt, dont believe all you read as its doesnt make sense to buy one on price/performance and it has a fault in having no temperature sensor leaving it less efficient than a cheap regulator that has a temperature sensor. The temperature sensor is key to good winter charging as it is designed to raise the voltage to well over 15v in cold weather which is necessary to fully charge cold batteries. ( just for the record if you remove the temperature sensor from a regulator in warm weather, the voltage spikes up over 15v and i ve seen double the amps to the battery when done.) To put it bluntly, any temperature controlled regulator is better than a fixed voltage one like the mppt one mentioned and the £70 would have bought a second 80w panel !!
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Post by Etienne Le Croq on Sept 10, 2013 20:59:48 GMT
Why do people buy 80 watt panels when you can buy 100 watt ones that are the same dimensions ,but only a few pounds more
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Post by ross on Sept 10, 2013 21:32:51 GMT
Why do people buy 80 watt panels when you can buy 100 watt ones that are the same dimensions ,but only a few pounds more www.amazon.co.uk/gp/product/B0086U7LJO/ref=oh_details_o05_s00_i00?ie=UTF8&psc=1I got this one some months ago & easily installed for last summer. Seemed a competitive price compared to some of the specialist solar suppliers. Certainly provided enough juice to power all the elec needs in the summer months, but I suspect that I might need more for winter use.. I plan to stick with one panel for now & see how it performs. Most panels come from Asia where technology keeps advancing & prices falling. Wait a year or so and it should be possible to get a 200W panel in similar size for similar price!
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Post by Etienne Le Croq on Sept 11, 2013 6:06:14 GMT
Good price that one Ross! I'm the same ,have a 100 watt at the moment,but not much space for another.Looking to upgrade to 200 watt panel next year .
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