Can i use these panels? (1 Viewer)

Elias

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Hi All,

We are in the process of building our second camper & i am looking to use 2 solar panels that i believe came from a house set up (from a clearance)

The model number is Talesun TP660P-250, they are 250w each & are 37.3v.

Link: http://www.solardesigntool.com/comp...1853/TP660P-250/specification-data-sheet.html

I have a good idea when it comes to electrics but useless with all the solar power stuff, im going to have a battery bank of 220ah over 2 batterys (12v). firstly would i be able to use these panels? and what sort of controller will i need to run them?

Thanks in advance..
 
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I believe you can use those. I would recommend a good quality controller such as the Victrons.
http://amzn.to/2kGSG00

Choose the right one.

Cheaper Units that work across 2 voltages (solar voltage/battery voltage) have been known to cause problems mis-sensing the battery voltage and boiling them...
 

Flamenca

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I believe you can use those. I would recommend a good quality controller such as the Victrons.
http://amzn.to/2kGSG00

Choose the right one.

Cheaper Units that work across 2 voltages (solar voltage/battery voltage) have been known to cause problems mis-sensing the battery voltage and boiling them...

I do not disagree with you regarding a quality controller if you have limited space on the roof for a solar panel. However as a 'quality controller' can equate to the cost of maybe 4 or 5 solar panels I would recommend fitting as many panels as the roof will reasonable accommodate before fitting an expensive controller. I went for a 'budget' controller and have never been let down by 'flat' batteries.

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Feb 27, 2011
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I do not disagree with you regarding a quality controller if you have limited space on the roof for a solar panel. However as a 'quality controller' can equate to the cost of maybe 4 or 5 solar panels I would recommend fitting as many panels as the roof will reasonable accommodate before fitting an expensive controller. I went for a 'budget' controller and have never been let down by 'flat' batteries.
Can I suggest you look at @Elias post again please. His/Her panel is 37.3V which is a voltage higher than a nominal 24V system but lower than a nominal 36V system so he/she needs a decent controller that can handle the high voltage input and a normal 12V battery bank.

As they already have the 500Watts of solar panel and just need the controller... The spend on a decent quality controller that won't boil the batteries is well worth the spend in my opinion.

I have seen situations with cheaper controllers where they automatically select battery voltage selecting 24v on a 12v battery bank. It is not worth the risk of a fire or boiled batteries in an expensive motorhome. You can trust the victron to get this basic thing right and they support the high voltage inputs nicely.

If you have a controller that handles this nicely for you, can you provide a link please :)
Alternatives are always nice to have (y)

But as they say, opinions are like buttholes. Everyone has one :p
 

funflair

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Well 1.6metre x 1metre they are pretty big panels so for starter you need to find room for them, secondly at total output of 500watts and open circuit voltage of 37volts you will be limited to the choice of controllers that can handle this output, yes I would go for a quality MPPT controller.

Martin
 

Flamenca

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Can I suggest you look at @Elias post again please. His/Her panel is 37.3V which is a voltage higher than a nominal 24V system but lower than a nominal 36V system so he/she needs a decent controller that can handle the high voltage input and a normal 12V battery bank.

As they already have the 500Watts of solar panel and just need the controller... The spend on a decent quality controller that won't boil the batteries is well worth the spend in my opinion.

I have seen situations with cheaper controllers where they automatically select battery voltage selecting 24v on a 12v battery bank. It is not worth the risk of a fire or boiled batteries in an expensive motorhome. You can trust the victron to get this basic thing right and they support the high voltage inputs nicely.

If you have a controller that handles this nicely for you, can you provide a link please :)
Alternatives are always nice to have (y)

But as they say, opinions are like buttholes. Everyone has one :p

Well, seems to me that the OP is using the wrong panels and fitting a very expensive controller will not result in a good solution. I suppose the answer is to fit an appropriate combination of panels and controller. One very expensive controller might equate to the cost of a complete installation. I have been using panels for houses and MHs for some 20 years and have never needed to fit an 'expensive' controller. It seems to me that in particular people with MHs want to fit the very best controllers regardless of whether it is the correct financial soluition and those people tend to not be interested in economics. All I can say is that mine work for me.

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Minxy

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Are 'house' panels up to being bumped around on top of a motorhome? Are they built differently for example? Never examined one so can't say but just something to check first.
 

funflair

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If the OP already has the panels then another £250 on a decent MPPT controller makes a pretty cheap 500watt system in my book.

Martin
 

funflair

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Are 'house' panels up to being bumped around on top of a motorhome? Are they built differently for example? Never examined one so can't say but just something to check first.
At 1 metre wide I would be tempted to put a support on the middle.

Martin

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Flamenca

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Well Mel, I am reluctant to answer because I might be shod down in flames. All I will say is yes and no. Are they 36 volt panels (please do not quibble about exact voltage)?
My policy, generally, is cheap panels and cheap controllers provides the most output per £. If a controller costs the equivalent of 5 panels, excluding installation, then surely you are on a loser.
 

funflair

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Well Mel, I am reluctant to answer because I might be shod down in flames. All I will say is yes and no. Are they 36 volt panels (please do not quibble about exact voltage)?


With that output why bother to fit an MPPT controller?

Yes 36volt near as,

Why MPPT 30% more power for a little bit more money and certainly lighter than more panels.

Martin
 

Flamenca

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Why MPPT 30% more power for a little bit more money and certainly lighter than more panels.

Sorry but a MPPT controller is not a 'little more money'. An MPPT controller can me the cost of 5 panels and if you theoretically gain only 30% more battery charge it just does not make sense unless you have limited roof space and are prepared to pay the premium.

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funflair

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Sorry but a MPPT controller is not a 'little more money'. An MPPT controller can me the cost of 5 panels and if you theoretically gain only 30% more battery charge it just does not make sense unless you have limited roof space and are prepared to pay the premium.
A Votronic MPP350 for £150 will handle 4x80watt panels, an extra 25% to 30% output is the same as one more 80w or 100w panel which would cost £100 to £120 so yes it saves roof space and weight up top so the numbers work for me.

Martin
 

funflair

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Where has the economic sense gone in this thread?
So if the OP wants 500w or even 250w of solar and has the panels sat in the shed is there a more economic way of doing it, yes it would be cheaper with a Non MPPT controller, but5 apart from that.

Martin

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Flamenca

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A Votronic MPP350 for £150 will handle 4x80watt panels, an extra 25% to 30% output is the same as one more 80w or 100w panel which would cost £100 to £120 so yes it saves roof space and weight up top so the numbers work for me.

Martin

That's fine if it works for you. I do not question your decision. I don't know what demand you have every day for 320W panels. That would support me off grid for quite a while ignoring battery capacity. The 25% to 30% is obviously theoretical and inferred by the controller manufacturers. An 80W panel certainly does not cost £100. All I am saying is go for as much solar output before looking at expensive controllers. I have never, ever, needed an expensive controller on a house off grid or a MH. The maths is really simple but can be obscured by exagerated claims of supposedly MPPT controllers. The decision for MH panels and controllers is usually dictated by the available roof area.
 

Flamenca

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So if the OP wants 500w or even 250w of solar and has the panels sat in the shed is there a more economic way of doing it, yes it would be cheaper with a Non MPPT controller, but5 apart from that.

Martin

Yes, he has the panels in a shed. But what is the sense of recommending a £150 to £250 controller? If I had 500W panels on my roof I definitely would not NEED an expensive controller.
 

funflair

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That's fine if it works for you. I do not question your decision. I don't know what demand you have every day for 320W panels. That would support me off grid for quite a while ignoring battery capacity. The 25% to 30% is obviously theoretical and inferred by the controller manufacturers. An 80W panel certainly does not cost £100. All I am saying is go for as much solar output before looking at expensive controllers. I have never, ever, needed an expensive controller on a house off grid or a MH. The maths is really simple but can be obscured by exagerated claims of supposedly MPPT controllers. The decision for MH panels and controllers is usually dictated by the available roof area.

Just for my own benefit I did a side by side test of MPPT vs PWM controller and I can certainly say that for me the Votronic claims stack up and show a real 25% to 30%, apart from that we are going around in circles.

Martin

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Feb 27, 2011
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PWM stepping down 37V to 12v is incredibly wasteful.

PWM works by switching the input on and off so that the average power over time results in the correct charge voltage. When the PWM is switched off no power is flowing from the panel to batteries. The higher the voltage step the longer the off period and the more power is wasted. For a 12V panel to a 12V battery this is not too critical. But for stepping 37V down to ~12v would be incredibly wasteful and the gain from going to a proper MPPT would give a lot more than 30% benefit.

As he has 2 x 250Watt panels which is around £500 worth. Starting from scratch to get the same quantity of panels in 12v and then a cheap PWM controller will work out more expensive.

I am not having a dig at anyone on this subject. I simply looked at the OP's current equipment and then suggested a suitable controller.

The one I suggested is the only one that will handle up to 48V the next model lower is 24V only which would not work on these panels.
 

Flamenca

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Just for my own benefit I did a side by side test of MPPT vs PWM controller and I can certainly say that for me the Votronic claims stack up and show a real 25% to 30%, apart from that we are going around in circles.

Martin

That's fine. But the cost of an MPPT controller surely far outweighs the additional 25 to 30 % gain. It is too late in the day to do the maths but solar panels are now cheap and MPPT controllers are still very expensive. To increase 60W to 80W panel costs maybe £20. Therefore to increse 180W to 240W panels costs something like £60. An MPPT controller costs maybe £150 therefore extra panels win hands down, assuming you have the roof area to mount them. Therefore my point is that you need only resort to an MPPT controller if you run out of roof space or decide otherwise for personal preference.
 
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Are 'house' panels up to being bumped around on top of a motorhome? Are they built differently for example? Never examined one so can't say but just something to check first.
Yes they are actually of similar construction if not better than the ones we put on our vans. The aluminium side rails on the one I have seen (only seen one) was much chunkier than the ones on my van currently.

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Flamenca

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As he has 2 x 250Watt panels which is around £500 worth

I have doubts that 2x250W 37 volt panels are worth £500 as a 120W panel starts at about £120 so worth in total about £240. I bought one myself for less than £100. It seems crazy to me to spend a further £150 to £250 to gain the extra 30%. Maybe the OP is best off selling his existing panels and buying a good package for his MH that suits their needs. I know that I am always looking for the optimum present worth on gear but I can not see the point of pumping good money after bad.
 
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I have doubts that 2x250W 37 volt panels are worth £500 as a 120W panel starts at about £120 so worth in total about £240. I bought one myself for less than £100. It seems crazy to me to spend a further £150 to £250 to gain the extra 30%. Maybe the OP is best off selling his existing panels and buying a good package for his MH that suits their needs. I know that I am always looking for the optimum present worth on gear but I can not see the point of pumping good money after bad.
Solar panels work out at around £1/Watt when I have been looking. So £500 watts would be £500 new. Your figure for 120w for £120 seems to agree with this.

Second hand a £250 watt panel would be around £100. So if he were to sell he may get £200 which would get him 200 Watts of new panels without a controller leaving him worse off.

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Flamenca

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Solar panels work out at around £1/Watt when I have been looking. So £500 watts would be £500 new. Your figure for 120w for £120 seems to agree with this.

Second hand a £250 watt panel would be around £100. So if he were to sell he may get £200 which would get him 200 Watts of new panels without a controller leaving him worse off.

Sorry I did not say that. I said that panels could be bought for about £240 in total which works out at 50p/Watt. A new 250 Watt panel can be purchased for about £120 retail and maybe less by shopping around. The cost of panels are continuing to fall but controller prices have been static or increasing. Second hand panels are available at near to zero. I know a very large solar farm which has recently been rapidly removed and I feel sure that the guy who took the panels away did not pay a penny. Efficiency of the controller does not equate to efficacy of the installation. The OP will definitely be worse off using a MPPT controller unless he has dire need of the extra output for which they will pay a very high premium. In general terms an MPPT controller is just burning money unless there is a NEED for gaining the extra output of a panel. Therefore, why spend the money if there is no need.
 

funflair

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That's fine. But the cost of an MPPT controller surely far outweighs the additional 25 to 30 % gain. It is too late in the day to do the maths but solar panels are now cheap and MPPT controllers are still very expensive. To increase 60W to 80W panel costs maybe £20. Therefore to increse 180W to 240W panels costs something like £60. An MPPT controller costs maybe £150 therefore extra panels win hands down, assuming you have the roof area to mount them. Therefore my point is that you need only resort to an MPPT controller if you run out of roof space or decide otherwise for personal preference.
When you do the maths on a MPPT controller matched to the panel output and then factor in that an extra panel will take you into the next size of controller (more money) you will find that it's around break even £20 either way, if you go for the Votronic controller with S+ AES output it will run your fridge for you when the solar is in excess so then you are saving gas overtime the sun comes out, every little bit counts.

Martin
 

eddie

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Just for my own benefit I did a side by side test of MPPT vs PWM controller and I can certainly say that for me the Votronic claims stack up and show a real 25% to 30%, apart from that we are going around in circles.

Martin
I have three 150w panels on the roof of my camper, wired independently each having its own regulator. This has allowed me to make simultaneous comparisons between many types of regulator. The difference is remarkable.

Some cheap regulators are so inefficient it is laughable when compared to the "claims" on the associated paperwork. We have concluded that if your "lucky" enough to get a decent "cheap" regulator an improvement of 25 -30% is achievable with a branded "known" MPPT regulator.

Personally I have Victron regulators fitted, along with a Victron bluetooth battery computer so I know exactly what is happening.

Everything in life is a compromise, to some payload is really important so the idea of additional panels is a non starter. To others the idea of buying something that is less efficient than another product is unthinkable. Roof space is another consideration. The Alden Phenix that we supply is on average five times more efficient than a conventional flt solar panel, however, at £2,500 plus installation it is very expensive, yet, we still sell them to people that wish to maximise their solar ability. As I say, I have three 150w panels as I have no roof space or payload issues so to me the Phenix is unnecessary, yet on the Van Bitz exhibition unit we have fitted a Phenix, partly for effect, but mainly as the exhibition unit has a larger than average appetite for 12 volt lol.

So the advice I would give is to check research and read reviews of any regulator anyone considers buying as even some MPPT regulators can be useless.

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all i will say is i fiffed to my last van a 28v out put solar panel to my last van i got a regulator from matilan German made 12v or 25v out put and cheep cant remember the speck but it worked fine 25v-28v 3v difrance controller it still works fine think it over for years now and still going strong on the van
bill
 

Minxy

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With 500w of solar already IMV I can't see the need for an expensive MPPT controller as the likelihood is that unless the OP is running something very power hungry they're never gonna need the extra 'possible' efficiency that an MPPT controller will give over a standard one. Whilst I like the possibility of running the fridge off the excess solar he could produce I assume this would require the fridge to be an AES one already, otherwise it would be a waste to get a controller with this facility.

When I fitted our 60w semi-flexible panel I fitted a standard LR1218 controller (about £75) as the LRM1218 MPPT one was double the cost which didn't make sense as I'd have been better off fitting a second panel for less money and get a 100% increase on the existing input rather than a max of 30% with a MPPT controller, as it is we've never had any issues with low batteries even with just a 60w panel and we wild camp for 6+ weeks at a time (no hook-up, just moving on).

If the OP doesn't actually need 500w of solar he could instead sell one and use that to buy an MPPT controller, obviously he wouldn't get as much input but it would mean he only had to fit one panel and save weight too, just another option.
 
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Well my view is that whatever panel you have you want to get the most out of it so spend the money and get an MPPT controller, you only spend the money once and you'll benefit for years. I suppose if motorhomeing was about spending the least amount of money possible I would reconsider.

Also, if you have got higher voltage panels they are essential to get anywhere near the rated wattage out of the panel.

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