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A question for you Techies out there, I have two 40 watt Solar panels which each have there own built in 10amp regulator attached to the rear of the panels .

If I want to use them both at the same time do I have to wire both panels through 1 regulator or can use both panels independently and just attach them straight to the battery ?

Would the two panels and regulators conflict with each other if both charging 1 battery ?

 

neil

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No problem at all if you wire them both positive to positive and negative to negative. (straight to the battery is same)

 

If you do it the other way in series you get 24 volts!

 

I don't like regulators fitted direct to the back of the panel because of heat issues but yours are probably fitted professionally so OK.

 

Keep the cables at a sensible length because of voltage drop. They will work well with each other. (regulators)

 

NB

 

As many panels as you like can be connected in parallel to a single controller as long as it has the

 

correct amperage to cope with the incoming amps from the panels.

 

A 40 watt is approx 2+ amps per hour so you are well covered.

Ford C-Max and Coachman Festival 380/2 SE 2006    Motto  Carpe Diem

Still trying to find the perfect pitch. ..110 amp Battery+ 65 watt roof mounted Solar and 25 watt Wind Turbine. LED lighting. Status Aerial 315. Loose chattels marked with UV,. Safefill Gas Fitted.

 

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Normally it is best to fit a regulator near the battery. It can be inside under the seats close to the battery box. This keeps the wires short between the two.

 

The Solar panel cable can then be long enough to allow it to be in the sunlight away from the caravans shadow.

 

Voltage drop occurs on longer wires but the solar is sending a higher voltage along the cable. The controller receives it and reduces it to send to the battery. When the battery is topped up the controller then prevents the incoming voltage from the panel.

 

Having the controller on the panel means the voltage is already reduced and the long cable may reduce it further.

 

The heat factor is obvious if you feel the panel when it is in full summer sunshine.

Ford C-Max and Coachman Festival 380/2 SE 2006    Motto  Carpe Diem

Still trying to find the perfect pitch. ..110 amp Battery+ 65 watt roof mounted Solar and 25 watt Wind Turbine. LED lighting. Status Aerial 315. Loose chattels marked with UV,. Safefill Gas Fitted.

 

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Hi,

I agree with lefthand, as he has pointed out the regulators on the back of the panels can (DO) get hot also the makers of " stand alone " regulators state that they should be no more than one metre ( 39" ) from the battery. This is because the voltage drop ( caused by the resistance of the wire ) in a long cable run can kid the regulator in to thinking the battery is fully charged. So in view of your regulators being mounted on the panels use a thick cable from them to the battery, also try to stand the panels clear of any obstructions if possible to allow the circulation of air to cool the control units.

david1220

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They look OK although as Dave and LHD have said the regulators attached to the back of the panels is not ideal.

 

There is not enough detail in the listing but if possible I would be looking to remove one if not both regulators from the panels, fit one into the van permanently in the battery box if possible and keep the other as a spare and to use the panels away from the van.

 

Otherwise disconnect the panels from one kit and extend the panel leads to reach the other panel controller. The two controllers will not be calibrated the same so running the outputs of these in parallel instead of the inputs could shut one off before the other.

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Hi,

While hairy fool has a good suggestion before coupling the panels together check to see if the controller can handle the combined output of both panels, perhaps there's a sticker on the control unit giving details ? Also,if you remove the control units from the panels and couple ( the panels ) them together in all possibility there will be no blocking diodes ( sorry if this is getting techy ! ) so if the situation arose of one panel in the shade and one panel in the sun the power would go from the "good" panel to the "dark " panel and not to the battery, in other words if you got two buckets and conected them with a hose, filled one with water it would flow into the other bucket ( sorry if this sounds as if i am " talking down to you" its not meant to be ! ) perhaps the best thing is for you to post all the info on the panels/ control units and see if we can help further

david1220

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Hi,

Just looked a your o. p. and have noted the output figures of the panels and the max current of the regulators. You should be O. K. with one regulator but the thing about one panel draining into another still stands i am afraid. Pity its this time of the year and not early summer --- we stop at a C. L. outside Bridekirk ! on a regular basis on our travel to/ from the North.

david1220

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Looking at the pictures the panels are already 2 panels into one regulator so would have the problem you describe if they were 4 into one, the blocking diode should be in the small junction block on the back of each panel. The regulators look like they are standalone modules that have been mastiked on to the back.

 

I am watching the 2 listings of the product myself at the moment.

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Looking at the pictures the panels are already 2 panels into one regulator so would have the problem you describe if they were 4 into one, the blocking diode should be in the small junction block on the back of each panel. The regulators look like they are standalone modules that have been mastiked on to the back.

 

I am watching the 2 listings of the product myself at the moment.

 

 

I'ii let you into a secret, I only meant to buy one 40 watt panel but had previously been outbid on no less than 5 previous occasions on the same panels advertised by the seller so I put £ ? bid on a further two not expecting to win either .

Won the first panel and totally forgot about the second one, should have withdrawn my bid but didn't and ended up with another :wacko: :wacko:

 

Hi,

Just looked a your o. p. and have noted the output figures of the panels and the max current of the regulators. You should be O. K. with one regulator but the thing about one panel draining into another still stands i am afraid. Pity its this time of the year and not early summer --- we stop at a C. L. outside Bridekirk ! on a regular basis on our travel to/ from the North.

david1220

 

 

Which CL is you use ? can't think where you talking about unless it's the Whins near Ecclefechan

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I'ii let you into a secret, I only meant to buy one 40 watt panel but had previously been outbid on no less than 5 previous occasions on the same panels advertised by the seller so I put £ ? bid on a further two not expecting to win either .

Won the first panel and totally forgot about the second one, should have withdrawn my bid but didn't and ended up with another :wacko: :wacko:

 

You will save a lot with the two if it means you can now avoid using EHU's

Ford C-Max and Coachman Festival 380/2 SE 2006    Motto  Carpe Diem

Still trying to find the perfect pitch. ..110 amp Battery+ 65 watt roof mounted Solar and 25 watt Wind Turbine. LED lighting. Status Aerial 315. Loose chattels marked with UV,. Safefill Gas Fitted.

 

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As Lefthand Down says I would probably get away with running both panels independently but together if you know what I mean and as I understand both regulators should work well together, just keep the cables as short as possible to avoid power loss

 

 

You will save a lot with the two if it means you can now avoid using EHU's

 

Yes I was hoping to do this next season as the C&CC charge £3 approx for electricity each night which soon mounts up

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Hi Neil & Lena,

You are --Spot on ! its Whins, can recommend the pub in Bridkirk if you are in that area, don't let the pink colour ( of the pub ) put you off, the meals are fantastic, the owner is a ex chief steward, P &O line. However its solar panels we should be talking about ! There's one aspect we have not touched on ,-that of output. Now as you have said they are 40 watts output and so they are,--- in the middle of the sahara desert in the middle of ( their ) summer ! the makers check the output by putting a meter across the output wires, so you will get near 40 watts( per panel ) but at near enough 0 volts. This is of no use as we require say 14. 8 volts ( no load ) to charge the battery and to allow for losses in the control unit, this will reduce the rated output. Now this is a guess ,- it depends where you are -- but you could get say,around 50 to 60 watts output. As i said earlier it depends where you are, in the North of Scotland you will get a lower output than in Cornwall because Cornwall is nearer the sun. Also it matters as to whether you lay the panel down ( say on the caravan roof ) this will reduce the output except at midday on the longest day ! and then only for a short while. We have in the past put ours on the roof -- stops /reduces them from "walking" today i have fitted a bonded on panel ( 68 watts ) to the roof ( Hairy Fool ,-we have a new Amara,- Coachman say you can go on the roof -no prob's ,-put it to the test today ) one last thing -how to work out watts & amps ,-- multiply volts by amps gives watts likewise divide watts by volts to get amps.

Regards david1220

Edited by david 1220
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Hi Neil & Lena,

You are --Spot on ! its Whins, can recommend the pub in Bridkirk if you are in that area, don't let the pink colour ( of the pub ) put you off, the meals are fantastic, the owner is a ex chief steward, P &O line. However its solar panels we should be talking about ! There's one aspect we have not touched on ,-that of output. Now as you have said they are 40 watts output and so they are,--- in the middle of the sahara desert in the middle of ( their ) summer ! the makers check the output by putting a meter across the output wires, so you will get near 40 watts( per panel ) but at near enough 0 volts. This is of no use as we require say 14. 8 volts ( no load ) to charge the battery and to allow for losses in the control unit, this will reduce the rated output. Now this is a guess ,- it depends where you are -- but you could get say,around 50 to 60 watts output. As i said earlier it depends where you are, in the North of Scotland you will get a lower output than in Cornwall because Cornwall is nearer the sun. Also it matters as to whether you lay the panel down ( say on the caravan roof ) this will reduce the output except at midday on the longest day ! and then only for a short while. We have in the past put ours on the roof -- stops /reduces them from "walking" today i have fitted a bonded on panel ( 68 watts ) to the roof ( Hairy Fool ,-we have a new Amara,- Coachman say you can go on the roof -no prob's ,-put it to the test today ) one last thing -how to work out watts & amps ,-- multiply volts by amps gives watts likewise divide watts by volts to get amps.

Regards david1220

 

 

Hi David thanks for your reply and how to work out the panel outputs I intend to use the panels as freestanding and just position them as close to the battery box as possible but where they will hopefully catch the sun for most of the day .

The Whins CL is only 6 miles from where we live but as its so close to home we have not stayed there however I can vouch for the pub at Brydekirk and as you say the food is excellent .

 

regards Neil

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Hi Neil,

What the heck are you doing up at 4. 54 a. m. - cant sleep ? glad you are now ( i hope ) sorted, 6 miles away ? it was once said to me by an" old hand "- distance dont matter, and its true its being in the van that counts ! We often " do " ( walk ) the hill behind Whins and have been up Criffell ( should be cripple = That hill is ---- steep ! )

regards david1220

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Hi Neil,

What the heck are you doing up at 4. 54 a. m. - cant sleep ? glad you are now ( i hope ) sorted, 6 miles away ? it was once said to me by an" old hand "- distance dont matter, and its true its being in the van that counts ! We often " do " ( walk ) the hill behind Whins and have been up Criffell ( should be cripple = That hill is ---- steep ! )

regards david1220

 

 

Hi David I was up for an early morning cuppa just before 5am , don't usually surface as early as that but for some reason I woke early and SWMBO was snoring away big time :wacko: :wacko: so no chance of getting back to sleep .

I have both panels connected up and they appear to be charging ok even in daylight with only the odd glimmer of sun and both regulators appear to be working together without conflicting .

Edited by neil and lena
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Some types of panels work without Sun better than others. Mono Crystalline particularly.

Ford C-Max and Coachman Festival 380/2 SE 2006    Motto  Carpe Diem

Still trying to find the perfect pitch. ..110 amp Battery+ 65 watt roof mounted Solar and 25 watt Wind Turbine. LED lighting. Status Aerial 315. Loose chattels marked with UV,. Safefill Gas Fitted.

 

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Hi Neil,

Now we seem to have sorted out the solar panels perhaps we should look at S. W. M. B. O. s -er-"noise making " ?

regards david1220 :D

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Hi Neil,

Now we seem to have sorted out the solar panels perhaps we should look at S. W. M. B. O. s -er-"noise making " ?

regards david1220 :D

 

I wish :huh: :huh: When I suggested a visit to the Doctor all I got was " Well I cant here it " so it cant be that bad :wacko: :wacko:

Edited by neil and lena
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