VicS
Well-Known Member
The 24 volt one you gave the ebay number for
No way is 29.2 the correct OC volts for a 24 volt panel
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Solar panel
- Thread starter capsco
- Start date
The 24 volt one you gave the ebay number for
No way is 29.2 the correct OC volts for a 24 volt panel
William_H
Well-Known Member
PV panels
Yes as said this PV panel is made for driving an inverter to supply mains 240VAC into grid or house.
I have just had 8 similar panels fitted each giving about 30 volts open circuit. They are wired in series.
The panel described is not IMHO suitable for a 24v battery direct charge.
It may charge a 12v battery fairely successfully but at a waste of power. If the OP can't get an exchange on the panel then best bet would be to feed it into an MPPT regulator then to charge the 24v battery. However make sure the MPPT controller maker agrees it will work cos they are expensive.
This panel fed into a 24v battery will start to reduce in current as battery becomes charged. ie the battery will need 28 to 29 volts to be charged fully while at 29 volts the current will be quite low. Maybe that will suit OP. What happens is that as the current is drawn from the panel the voltage falls.(in a more linear manner than other charge sources) As the voltage of charging into the battery falls the current falls. So it will settle to a medium of current into the battery which is far less than the 100w capability of the panel. If there is a load on the battery and voltage goes down then solar will supply more current. good luck olewill
Yes as said this PV panel is made for driving an inverter to supply mains 240VAC into grid or house.
I have just had 8 similar panels fitted each giving about 30 volts open circuit. They are wired in series.
The panel described is not IMHO suitable for a 24v battery direct charge.
It may charge a 12v battery fairely successfully but at a waste of power. If the OP can't get an exchange on the panel then best bet would be to feed it into an MPPT regulator then to charge the 24v battery. However make sure the MPPT controller maker agrees it will work cos they are expensive.
This panel fed into a 24v battery will start to reduce in current as battery becomes charged. ie the battery will need 28 to 29 volts to be charged fully while at 29 volts the current will be quite low. Maybe that will suit OP. What happens is that as the current is drawn from the panel the voltage falls.(in a more linear manner than other charge sources) As the voltage of charging into the battery falls the current falls. So it will settle to a medium of current into the battery which is far less than the 100w capability of the panel. If there is a load on the battery and voltage goes down then solar will supply more current. good luck olewill
VicS
Well-Known Member
Yes.
I have just looked again at the spec on ebay.
I missed it first time but now notice that its voltage at max power output is 24 volts.
So the 29.2 volts OC circuit volts is not incorrect after all!
Its not really suitable for charging a 24 volt battery ... which is fair enough because no where does it suggest that it is intended for that purpose.
If it was for battery charging then the OC volts would be nearer to 40 volts and the volts at max power output would be around the 16 volts mark.
It will charge your 24 volt battery to some extent but not at the rate you expect.
Fortunately they say you can return it for a full refund if you are not happy for any reason
I have just looked again at the spec on ebay.
I missed it first time but now notice that its voltage at max power output is 24 volts.
So the 29.2 volts OC circuit volts is not incorrect after all!
Its not really suitable for charging a 24 volt battery ... which is fair enough because no where does it suggest that it is intended for that purpose.
If it was for battery charging then the OC volts would be nearer to 40 volts and the volts at max power output would be around the 16 volts mark.
It will charge your 24 volt battery to some extent but not at the rate you expect.
Fortunately they say you can return it for a full refund if you are not happy for any reason
Q: What if I am not happy with my purchase?
A: If for any reason you are not happy, you can return your item for a refund / exchange. Please contact us for further details or see our returns policy.
A: If for any reason you are not happy, you can return your item for a refund / exchange. Please contact us for further details or see our returns policy.
nigelmercier
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Although MPPT regulators are excellent, they are a bit OTT for a solar panel. The output could be fed into a simpler DC/DC converter, but a better solution may be to start over.
capsco
Well-Known Member
Thanks for all the replies, very helpfull as usual.
My boat may well be left without the benefit of shorepower this winter, hence looking for a solar solution, domestic batts are 360amp @24v, I have 0.1A drain when all switched off, I have so far failed to locate the source, boat is in France so time is running out.
My initial thought was purely to replace the small loss with solar but then decided I may as well go for a reasonable size panel at the same time.
I know I should find the problem 1st but would still like to take advantage of the French sun [been a bit hit & miss so far this season] any suggestions please.
My boat may well be left without the benefit of shorepower this winter, hence looking for a solar solution, domestic batts are 360amp @24v, I have 0.1A drain when all switched off, I have so far failed to locate the source, boat is in France so time is running out.
My initial thought was purely to replace the small loss with solar but then decided I may as well go for a reasonable size panel at the same time.
I know I should find the problem 1st but would still like to take advantage of the French sun [been a bit hit & miss so far this season] any suggestions please.
greenalien
Well-Known Member
Assuming that it's not a fault, current drain may be for memory retention on something like a radio, particularly if you have a car type installed. Could also be for gas alarm or bilge pump level sensor. Look for small wires that connect directly to your batteries.
capsco
Well-Known Member
Excellent service
Well after the forum established that I had purchased the wrong type of panel, I contacted the suppliers, Sunrise Energy Nottingham, they agreed to collect the panel tomorrow FOC.
As they were in no way to blame I think they deserve a very strong recomendation, the initial delivery was also excellent, ordered at 10.30am delivered am next day.
Before I can order a replacement from them I need a little more advice please.
What are your thoughts of the SOL-1 MPPT regulator [my system is 24v] to go with an 80w 12v panel, or even 2x 80w panels in parallel, bearing in mind that the max wattage for the reg is said to be 100w, with 2 in parallel, would I have 80w or 160w?
Well after the forum established that I had purchased the wrong type of panel, I contacted the suppliers, Sunrise Energy Nottingham, they agreed to collect the panel tomorrow FOC.
As they were in no way to blame I think they deserve a very strong recomendation, the initial delivery was also excellent, ordered at 10.30am delivered am next day.
Before I can order a replacement from them I need a little more advice please.
What are your thoughts of the SOL-1 MPPT regulator [my system is 24v] to go with an 80w 12v panel, or even 2x 80w panels in parallel, bearing in mind that the max wattage for the reg is said to be 100w, with 2 in parallel, would I have 80w or 160w?
noelex
Well-Known Member
That is good service from sunrise energy.
The SOL-1 MPPT regulator is one of the very few MPPT regulators that will boost voltage. I do have some reservations about its battery charging points, but a freind who has fitted one is reporting very good results.
2X80W panels will give you 160W and would exceded the specs of a single SOL-1
The SOL-1 MPPT regulator is one of the very few MPPT regulators that will boost voltage. I do have some reservations about its battery charging points, but a freind who has fitted one is reporting very good results.
2X80W panels will give you 160W and would exceded the specs of a single SOL-1
pappaecho
Well-Known Member
I am a bit unhappy with fitting a 24 volt regulator to a 12 volt panel, which I seem to understand from your last post.
You have two distingt posibilities.
Firstly charge the batteries at 12 volts using a changeover switch, or relay. That means you charge the 12 volt batteries, and then link them in series to make a 24 volt system. You have to be very careful to use a special changeover circuit, because of the current draw when starting engines etc, which will fry everything in sight if you get it wrong.
I have a 24 volt bow thruster, and use this system.
The alternative is to connect 2 panels in series to give 24 volt charging, and a Voc of nearly 40 volts, and a typical actual charge at battery Vpm of about 28 volts via a charge controller.
If you connect 2x 80 watt panels in series to produce 24 volts, you will have an 80 watt input at 24 volts, so a max of 6.3 amps, which should be enough for most installations. (My single 80 watt 12v panel does 640 amp hours of battery banks with no problem) .
My current panel came off Ebay in January at £149, so two off would cost about the same as your panel, which got me thinking about putting an array on my kitchen roof.
You have two distingt posibilities.
Firstly charge the batteries at 12 volts using a changeover switch, or relay. That means you charge the 12 volt batteries, and then link them in series to make a 24 volt system. You have to be very careful to use a special changeover circuit, because of the current draw when starting engines etc, which will fry everything in sight if you get it wrong.
I have a 24 volt bow thruster, and use this system.
The alternative is to connect 2 panels in series to give 24 volt charging, and a Voc of nearly 40 volts, and a typical actual charge at battery Vpm of about 28 volts via a charge controller.
If you connect 2x 80 watt panels in series to produce 24 volts, you will have an 80 watt input at 24 volts, so a max of 6.3 amps, which should be enough for most installations. (My single 80 watt 12v panel does 640 amp hours of battery banks with no problem) .
My current panel came off Ebay in January at £149, so two off would cost about the same as your panel, which got me thinking about putting an array on my kitchen roof.
VicS
Well-Known Member
Er I dont think that is right.
2x 12 volt 80watt panels in series will give you 160 watts at 24 volts
2 X 12 volt 80 watt panels in parallel will give you 160 watts at 12 volts.
noelex
Well-Known Member
I think Capso has a 24v house bank. The regulator he is talking about will boost the output of a 12v panel and then regulate it (although only simply according to the specs) for a 24v bank.
2 X 80w panels will always produce 160w.No matter how they are connected.
In series add the V and leave A unchanged. In parallel add the A and leave the V unchanged
capsco
Well-Known Member
Thanks again for all input, so choice now seems to be, 1x 80w panel + Sol-1 mppt regulator, or 2x80w panels in series with simple PWM regulator.
My house bank is 24v 360ah, for and against???
My house bank is 24v 360ah, for and against???
VicS
Well-Known Member
A very significant consideration will be if you want 80watts or 160 watts of solar power I would think!
An mppt controller on single 80 watt panel will give you bit more but not as much as 2 X 80watts.
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capsco
Well-Known Member
Yes I asked for that.
Initially 80w would do me for this winter but If I want to up grade later I would also have to purchase another regulator if I went with the MPPT, I do like the idea of the MPPT as it is claimed to be more effective in dull [winter] conditions it seems that experience of the SOL-1 is not widespread, at least not on here.
Initially 80w would do me for this winter but If I want to up grade later I would also have to purchase another regulator if I went with the MPPT, I do like the idea of the MPPT as it is claimed to be more effective in dull [winter] conditions it seems that experience of the SOL-1 is not widespread, at least not on here.
nigelmercier
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- Live in Kent, boat in Canary Islands
MPPT is a more efficient way to transfer power from one device from another, but you would be better off spending your money on an extra panel.
noelex
Well-Known Member
On average on a boat the best MPPT ,on a boat, will produce an extra 5-10%. In cold conditions with flattish batteries maybe 10-15%.
Poor MPPT regulators produce very little gain and in some cases a loss. The SOL-1 is inexpensive but looks like it has it has a reasonably sophisticated MPPT circuitry, it does however have only very simple battery regulation which will cost some power.
2x80W panels will give you much more power than 1x80 and MPPT, but as you need to wire them in series the power will be very much reduced if either panel becomes shaded. So this option is poor if one panel will often be in shade (say mounted on the guardrails on either side of the boat). If you can mount them where both panels will see similar conditions (shade or sun) the 2X80w 12v panels is a reasonable option.
2x80 proper 24v panels with a simple regulator would be the best choice if this available from the supplier.
Poor MPPT regulators produce very little gain and in some cases a loss. The SOL-1 is inexpensive but looks like it has it has a reasonably sophisticated MPPT circuitry, it does however have only very simple battery regulation which will cost some power.
2x80W panels will give you much more power than 1x80 and MPPT, but as you need to wire them in series the power will be very much reduced if either panel becomes shaded. So this option is poor if one panel will often be in shade (say mounted on the guardrails on either side of the boat). If you can mount them where both panels will see similar conditions (shade or sun) the 2X80w 12v panels is a reasonable option.
2x80 proper 24v panels with a simple regulator would be the best choice if this available from the supplier.
capsco
Well-Known Member
OK thanks all, both panels will be flat on coachroof side by side, no shadows, so it seem like it will be 2 x 80w 12v panels in series with simple reg.
noelex
Well-Known Member
In a location with little shadowing (or where both panels get the same shadowing) that will give you the most Ahrs per $.
elton
Well-Known Member
True.
fishermantwo
Well-Known Member
I agree that this is the best set up except I would have the two panels at an angle, preferably 45 degrees. Mount them like the navigation buoys and highway solar panels. Having them flat means that when the sun is hitting them at a reasonable angle they are also expected to work at the hottest time of the day and performance drops off above 25 degrees c. Black panel will get to 25 degrees fairly fast.
