Solar Panel - how many watts is it?

RowleyBirkinQC

RowleyBirkinQC

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Apologies if this is a silly question due to my ignorance! The van we bought second hand last autumn came with a solar panel already installed. I'm contemplating whether we should fit a second solar panel in case we do more wild camping / stay at sites without EHU etc.

With this in mind, is there a way to easily identify the wattage of the existing panel? Would the wattage of the existing panel in anyway influence or dictate which second panel should or could be installed?

Thanks in advance for any pointers!
 
No question is silly on here. There is usually someone else that would like to know the answer but hasn't got round to asking.
That's me so I will be following this thread with interest. (y)
 
Regardless of the wattage of your existing panel, it has no bearing on the wattage of any other panel you add. Add whatever you like.
The size of the panel will give a good idea of the wattage.
 
Do not agree with the above as if its 100w pannel and you add another 100w it can over load say a sargent system which states 120w max.

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If you have a small inspection mirror, try to look on underside of panel, there is often a spec label stuck there. Usually just below terminal box. Just read it in reverse, you'll either have WOOl, WOB or WOd ish haha. (y)
 
And as Laurieash alluded to, we need to know the size of the regulator, (small box that has connections from the existing panel to the batteries.) Should have the 'ampage' written on it.

Sorry in advance for dumbing down my comments but I/We don't know your knowledge.
 
Hope OP does not mind me butting in. I am in exactly the same situation, existing panel is 120cm x 32cm. Pic of the regulator below.

Solar Reg.jpeg
 
Encantador said:
Hope OP does not mind me butting in. I am in exactly the same situation, existing panel is 120cm x 32cm. Pic of the regulator below.

View attachment 55424
Click to expand...
Not a very common size but by surface area I would guess at around 50 watts, also depends on type for a given output a Polycrystallinewill be larger than a Monocrystalline panel.

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Thanks, so not very big then.

Can a second panel be fitted (plenty of roof space) and fed into the same regulator?
If it can, what would be a good size to go for and where from?

I have been quoted £75 (3 hours labour) just to fit, does that sound about right?

Thanks
 
Encantador said:
Thanks, so not very big then.

Can a second panel be fitted (plenty of roof space) and fed into the same regulator?
If it can, what would be a good size to go for and where from?

I have been quoted £75 (3 hours labour) just to fit, does that sound about right?

Thanks
Click to expand...
Are you sure your sizes are right 120x32 is 47" x 12½".
Labour rate sounds cheap most dealers charge at least £40 hour, I would expect them to couple the cables with MC4 connectors on the roof so shouldn't take that long, 1 - 1½ hours.

Your regulator is only 6.5 amps so you would need a new regulator, in bright sunlight a 100W panel can get up to 5.5 amps approx.
 
Encantador said:
Thanks, so not very big then.

Can a second panel be fitted (plenty of roof space) and fed into the same regulator?
If it can, what would be a good size to go for and where from?

I have been quoted £75 (3 hours labour) just to fit, does that sound about right?

Thanks
Click to expand...

You will need to ensure that the wire from the regulator to the leisure batteries is also up to the job, otherwise your wasting your money on the additional panel.

A good analogy is always water! Imagine a the biggest supermarket that you have ever been in!

Now imagine the surface area of the roof!

Now imagine that the roof is slightly sloped to the middle

Now imagine that it is raining, heavily!

Now imagine that there is a massive drain pipe in the middle of the sloping roof to take all of the water

Now imagine the diameter that pipe would need to be to handle that amount of water

Now imagine, instead of that huge pipe, replacing it with the down pipe on your house or bungalow :Eeek:

It would work, but not very well!

And that is why cable length and diameter are inportant.
 
Ref: to Eddies comment about cable looking at your photo, whoever installed your panel looks like the have used 1.25 or 1.5 mm sq mains cable, that would need replacing with at least 4 mm sq. cable.
 
Thanks, so clearly going to be more expensive than it might have been.

can anyone give me a idea of a good regulator.

Thanks

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Might as well get a new regulator to take how ever many panels you want, fit a MPPT and get 25 to 30 % more power, I did a test with two systems wired and the old sunsaver was 25 or 30% behind my new Votronic MPPT, changed it to another Votronic MPPT and now they match each other amp for amp.

Votronic told me if the panels are different put them on a separate controller.
 
Torch and a hand mirror.

It will have a data label underneath near the wiring terminal box

Oops...just seen wickolad's post.
 
funflair said:
Might as well get a new regulator to take how ever many panels you want, fit a MPPT and get 25 to 30 % more power, I did a test with two systems wired and the old sunsaver was 25 or 30% behind my new Votronic MPPT, changed it to another Votronic MPPT and now they match each other amp for amp.

Votronic told me if the panels are different put them on a separate controller.
Click to expand...

Does this mean leaving the panel and regulator I already have and adding a new regulator for the new panel? I assume both regulators can then feed the same leisure batteries?

Thanks
 
Better to replace the regulator, output of two regulators coupled togther will cause problems. Also has the added advantage you only need to run one set of cables down from the roof.
 
Encantador said:
Thanks, so clearly going to be more expensive than it might have been.

can anyone give me a idea of a good regulator.

Thanks
Click to expand...

Broken Link Removed what I use. Very happy with its performance (100+50 watt solar panels).
This would replace your existing controller and allow another panel (or two).

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This is interesting, I will have to have a gander at my panel and associated components - the only thing I know (if I recall correctly) I have is a "Fox-D1" box which shows voltage/amps on LCD display. does anyone know if this is the regulator or whether it just hooks into a regulator to show what is going on?
 
After looking through the folder full of papers which came with the van, assuming nothing has since changed, it seems we have a 90w solar panel onboard which was fitted by Solar Solutions in Poole. This is feeding 2 x 100A leasure batteries with a batterymate topping up the vehicle battery. I may see how we get on when not on EHU before changing it.

Guess I really should have looked there first before spawning this thread asking for guidance! :rolleyes:

Thanks for all your input though, I found it very useful. :)
 
With a 90 watt panel you will be fine from May through to September .

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lennyhb said:
With a 90 watt panel you will be fine from May through to September .
Click to expand...

It really depends where you are.

Panel ratings are absolute maximum which you will not get in the UK, even in summer. We have 160W panels and found that it all depended on our 12V consumption the day before. A good day would see the batteries right up, but a heavy day and clouds meant that they weren't. Three days of thunderstorms in Carpentras last year saw us getting the EHU cable out.

The Mercedes will have 4 X 100W panels and twin controllers as we are going to run longer without EHU this year.

We are fairly power-hungry with lights (LED) laptop charger, TV/Sat receiver etc etc.

Peter
 

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