Roof angle

[Amarillo]

Can anyone advise on the angle of the raised roof when parked on level ground?

The reason I ask is that for only the second time we've managed to drain our leisure battery. We have 200 Watts of solar panels on our roof, but have been parked for three days facing almost due south. The sun here rose to a maximum angle of 28.6' today, and I expect this and the angle of the roof are highly significant factors in our lack of battery power.

The clear implication for us, and anyone else relying on solar charging the leisure battery is to park facing north in winter months - obvious I know, but I'm always one to learn things the hard way.


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[Sad]

I'm imagining some GCSE levels maths with the vehicle dimension diagrams to work this one out

 

[B J G]

Logic says to park with slope facing south if you have solar panels on it. Not much point having it in the shadow.
Unless in the artic pole region mid summer then face anywhere.

 

[Amarillo]

I'm imagining some GCSE levels maths with the vehicle dimension diagrams to work this one out

Using vehicle dimensions: 1000mm for the front of the roof, and 320mm for the rear of the roof, and estimating the relevant section of the roof length to be 2500mm, I get 15.8'.

Looking at the roof I guesstimated a quarter of a right angle - i.e. 22.5'. For that to be correct, the relevant roof length would be 1777mm - that is clearly way out.

Assuming the 15.8' to be correct, the sun rose late on my solar panels and set early, striking my panels at just 12.8' at midday.

Parked the other way around, the sun could have hit them all day long at a minimum of 15.8' and almost 45' at midday.


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[Amarillo]

Logic says to park with slope facing south if you have solar panels on it. Not much point having it in the shadow.
Unless in the artic pole region mid summer then face anywhere.

Yes - it's damn obvious I know, but this is only the second time we've drained the leisure battery, so we haven't given the matter much thought.

Before we left home I did pack a decent navigation compass for such an eventuality as having to park facing north, and that compass has survived a thorough consolidation of our baggage. Now that we are into the three months of lowest sun (6 Nov to 6 Feb) we'll be making much use of it to enable us to stay off grid all winter.

I am still hopeful that we can manage the full year without hookup.


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[jts46]

If you stay at acsi sites during winter months the price includes ehu. We only paid €15 per night including ehu
Or perhaps using 12v kettle too much

 

[sidepod]

Using vehicle dimensions: 1000mm for the front of the roof, and 320mm for the rear of the roof, and estimating the relevant section of the roof length to be 2500mm, I get 15.8'.

Looking at the roof I guesstimated a quarter of a right angle - i.e. 22.5'. For that to be correct, the relevant roof length would be 1777mm - that is clearly way out.

Assuming the 15.8' to be correct, the sun rose late on my solar panels and set early, striking my panels at just 12.8' at midday.

Parked the other way around, the sun could have hit them all day long at a minimum of 15.8' and almost 45' at midday.


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I’ll bet you’re a riot at a party

 

[Wesel]

Usually we can stay 3 days without recharging, without hookup and without solar panels. But paying attention to consumption (fridge on 3 and minimum lighting)

 

[Amarillo]

If you stay at acsi sites during winter months the price includes ehu. We only paid €15 per night including ehu
Or perhaps using 12v kettle too much

We are paying 11 Euros for pitch, two adults, dog and EHU, plus 3 Euros for each of the boys. We've got one boy free on the basis that we don't use EHU, so 14 Euros total. Besides, we don't have a hookup lead.

I've put the roof down to catch more sun.

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[Amarillo]

Usually we can stay 3 days without recharging, without hookup and without solar panels. But paying attention to consumption (fridge on 3 and minimum lighting)

Nights are long and days short. We have loads of lights on from about 5pm, internal and external, fridge, phones, heater pump, DVD player...


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[marchugo]

Your pretty close with 15.8. Using a degree bow on this picture gives me roughly 16 degrees.




Are you sure the fuses are ok, esp. the one above the third battery in the boot? Maybe only one of the two camping batteries is loading.
Low sun decreases solar harvest, but only with appr. 2/3. At a clear day as today, my 6 Ah solar panel still brings 2 Ah, with the sun at 15 degrees and the roof not raised.

Sunny regards from Amsterdam,

Marc.

Assuming the 15.8' to be correct, the sun rose late on my solar panels and set early, striking my panels at just 12.8' at midday.

/QUOTE]

 

[Amarillo]

Your pretty close with 15.8. Using a degree bow on this picture gives me roughly 16 degrees.


View attachment 27583

Are you sure the fuses are ok, esp. the one above the third battery in the boot? Maybe only one of the two camping batteries is loading.
Low sun decreases solar harvest, but only with appr. 2/3. At a clear day as today, my 6 Ah solar panel still brings 2 Ah, with the sun at 15 degrees and the roof not raised.

Sunny regards from Amsterdam,

Marc.

What a useful reply.

We have a beach so just one leisure battery.

200w of panels currently charging with roof down at 13 volts and 2.3 amps. The volts seem particularly low.


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[sidepod]

 

[CALI FATE]

I know you havnt got one, but if you did buy a EHU lead, have you calculated the optimum length of the lead bearing in mind potential voltage drop between the source and the van

 

[B J G]

Might it be possible to construct a reflector using the heat insulating type foil and alloy/fibre rods to maximise the limited winter sun? Easier said than done.

Only alternative would be mains top up every few days or if touring pay for electric on some stops. Buy a mains reel extension as you'd only have low amperage going through it. Assume that the Beech came with an EU type plug cable. You'd need the 16Amp type plug also.

SatNav has a compass indicator.

 

[andyinluton]

What you really need is a car turntable as used in showrooms, you could then adjust the position of the van properly as the sun goes round. I know its going to be a bit of a pain having to adjust it every half hour or so, but it would give you something to fill the time waiting for a 12v kettle to boil.

Im sure you could get one that dismantles small enough to go on the roof bars.

You can get them on line for about £4,500 so pretty cheap really when you think its saved the cost of a £20 hook up lead and the £3 every couple of nights saving on hookup.

 

[bigmac77]

Have you cleaned the panels? They might be dirty.

 

[B J G]

Possibly fit a leisure battery with a greater capacity than you currently have. Check physical space available and what is currently fitted in Amphr rating then compare what's available on this site-

http://www.alpha-batteries.co.uk/leisure-batteries/

Ocean brochure says 2 x 75Ahr, no mention of Beech rating.

You could possibly uprate to a 140Ahr in same space.

 

[Amarillo]

Have you cleaned the panels? They might be dirty.

With the roof down and in bright sunshine, I can happily report the leisure battery showing 80%, and the panels charging at 17 Volts, 5.5 amps.

I'll give the panels a good clean and if I have to park facing south again in winter, I'll lower the roof in daytime.

Thanks for all other suggestions. I really do like the fact that we do not need to hook up, and don't feel that we are missing anything by not doing so, even though the cost of hookup is included with the ACSI camping card discount. We often get superb pitches with spectacular views off grid.


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[B J G]

Is that 17volts going to the battery? Presume you have an actual charge level controller to reduce that.

Battery shouldn't have above 14.4volts as it can cause boiling and drying out of cells reducing capacity or buckling plates.

 

[Amarillo]

Is that 17volts going to the battery? Presume you have an actual charge level controller to reduce that.

Battery shouldn't have above 14.4volts as it can cause boiling and drying out of cells reducing capacity or buckling plates.

Yes, I have an mppt charge controller.

I have Roger Donahue's setup.
http://www.solarcampersolutions.co.uk/index.php/shop/vw-t5-t6-bolt-on-solar-kit


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[andyinluton]

Ok , if you can't increase the charge going in, you need to reduce the usage somehow:
1. Can you get freezer blocks to cool the fridge & rely on them rather than 12v
2. Ditch the 12v kettle,
3. If your the only van on site, run the engine for a bit.
4. Go to bed earlier.
5. Increase the ratio of driving V parked up.
6. Additional stand alone solar panel to charge phones etc
7. Admit defeat & plug van into mains for a full charge once a week.

 

[Amarillo]

Ok , if you can't increase the charge going in, you need to reduce the usage somehow:
1. Can you get freezer blocks to cool the fridge & rely on them rather than 12v
2. Ditch the 12v kettle,
3. If your the only van on site, run the engine for a bit.
4. Go to bed earlier.
5. Increase the ratio of driving V parked up.
6. Additional stand alone solar panel to charge phones etc
7. Admit defeat & plug van into mains for a full charge once a week.

I thought post #19 made it clear that all is now ok.

Twice in over 130 almost consecutive nights without hookup we have drained the leisure battery. Once when we parked under a tree for several nights, and once when we parked facing south in winter with the roof up for four nights. I think that's a pretty good record for a family of four.

Our 12 volt kettle has a very specific use. It's for mornings when we have pre packed our gas and cooker because we are moving on that day. It drains much of the battery, but that doesn't matter as we will be driving for some 2 to 5 hours that same day and that will recharge the battery if poor weather stops the panels from doing it.

So:
Lesson 1. Don't camp under trees
Lesson 2. Don't camp facing south in winter, and if you do, put the roof down in daylight hours


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[Mofty in Meysey]

Love the enthusiasm of most to help with you with this....
Technically..... Angle doesn't matter, you have what you have, point it at the sun... you will find it in the south at about 12PM. It is the best indicator without a compass. when it isn't sunny it doesn't matter, there is so much diffusion you would be better with the roof flat. Clean the panels clearly and with the current you are generating clearly ensure it is regulated to the batteries. Also, Ensure the battery itself is in good shape, a cell down with warped and shorted plates will have a significant effect on its ability to hold a charge.
Hope that helps and its not driving you too mad... please also excuse the other members who are not seeing your concern with this, they are not being hurtful, they just don't see what you see.

 

[Amarillo]

Love the enthusiasm of most to help with you with this....
Technically..... Angle doesn't matter, you have what you have, point it at the sun...

Thank you for the sound advice, it's good to hear from someone who understands my enthusiasm for spending a full year as a family of four off grid. I always new winter would be harder than summer. We are now relying quite a lot on recharging the battery driving between campsites, with the panels boosting the battery charge but not fully recharging it.

I have given the panels a good clean and noted the charge before and after:
Before 16v 3.4 amps
After 17v 3.9 amps
A 20% boost.

Parked facing NW, (panels to the SE).

The battery is 9 months old so should be in good condition.

I accept what you say about the angle of the panels when sunlight is on them, but if facing north it will be significantly later in the morning when they get direct sunlight, and significantly earlier in the evening when they lose direct sunlight reducing the solar day from the panel's perspective very significantly.



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