solar panel.

[tony]

im sure this topic was covered before but to be honest i dont understand the jargon.
was looking at a panel on ebay a 15w for £59.95 item no 200427419792.
my question is would it suit me ?
we use our mhome all year, in winter 2 to 3 nights at a time mostly.
when at home it is on hook up.
its mostly lights we draw from the battery & they are l e d.no tv etc.
we have an inverter for the slow cooker we use only while travelling so the alternator is charging the battery.
your comments please all you good people what do you think ?
thanks all
tony
ps. can this be fitted to roof without drilling holes.
tony

 

[Neckender]

Hi Tony, I think 15 watt will only give you a trickle charge to keep the batteries topped up when parked up, not really when you're camping. I've fitted a 100watt to my van and we don't use hook up at all now, you don't have to drill the roof as you can sikaflex brackets to the roof.
I got our 100 watt off ebay for £135 if I remember right.

John.

 

[vwalan]

my view is dont waste your money .it can only put out 1amp at midday on the brightest day and then must keep following the sun. save up and get at least 1,2,3 80watt panels then you start to have some power . why spend good money .you just as well get a hamster in a cage with a wheel working a small dynamo. they arent worth having. be lucky if it can power an interior bulb for a few hours in bright sunshine. sorry but its a fact. cheers alan.

 

[winchman]

As above 15w at 12 volts will give you a whole 1.25 Amps on a good sunny day with a clean panel, so the other 48 weeks of the year it wont do much.
I would think you would only really benifit from a 100w or above but I am no expert.(100w gives 8.3 amps)
What you really need to do it turn everything on as you normally would and measure how many amps you use then calculate the size of panel to be bigger out put than what you use.

 

[Kontiki]

Would agree with the others that 15 watts isn't worth putting on & at best would only keep the batteries from going flat if your not using the van. Our panel is about 80/85 watt & our battery is 85 amp gel. The panel easily keeps my battery topped up & any larger panel wouldn't help, so you need to also have the battery capacity to match what size panel you have. There are also different types, some only work best in sunlight others like ours will work just with daylight (it will even put some charge in when it's raining )

 

[bevdrew]

Hi Tony

Agree with other posts - minimum panel you should be thinking of is an 80W.

We fitted 2 x 40W panels (from ebay) last year along with 2 new x 113AH batteries and find this setup perfect.

Four days "off grid" 11th - 14th June north east of Inverness, with radio, TV running off inverter most days/ evenings, and our "setup" coped brilliantly - batteries back up to full charge by 9am each morning.

I see the same ebay seller is offering an 80W panel for £185 at the moment (item number 130403231598).

We did a wee blog of the parts we required/fitting process but havn't published it yet - pm me if you want a copy.

Hope this helps

 

[vwalan]

that last price is a good one .you cant get them in morocco for that now. i have 3 x80watt and 600 amp of batteries .wewild camp all winter and never use ehu. try to never go on sites. use a house fridge on inverter . never have a problem. had panels for 10 yr. good move if you want flexibility. but forget 15watt.

 

[biggirafe]

Hi Tony
All the above are correct you need to sit down and do the maths with regards to what you actually use in your van. In short if you turn on a light and it uses 4 amps per hour then to keep your battery topped up you need to deliver 4 amps per hour, 2 bulbs then double it. use the water pump then a bit more. In summer this is not too much of a problem as the use of electric is sporadic and you have time between uses to top up the battery from your solar panel. In winter in the UK its difficult without becoming a mad monk sat in the corner with a single LED light.

Led's do help, lights are one of the worst offenders, the fan in your heating is another we don't use the fan unless we have too.

Below are some basic rules for conversion they may help.


The conversion of Watts to Amps is governed by the equation Amps = Watts/Volts

For example 12 watts/12 volts = 1 amp
Converting Amps to Watts

The conversion of Amps to Watts is governed by the equation Watts = Amps x Volts

For example 1 amp * 110 volts = 110 watts

Converting Watts to Volts

The conversion of Watts to Volts is governed by the equation Volts = Watts/Amps

For example 100 watts/10 amps = 10 volts

Converting Volts to Watts

The conversion of Volts to Watts is governed by the equation Watts = Amps x Volts

For example 1.5 amps * 12 volts = 18 watts

Converting Volts to Amps at fixed wattage

The conversion of Volts to Amps is governed by the equations Amps = Watts/Volts

For example 120 watts/110 volts = 1.09 amps

Converting Amps to Volts at fixed wattage

The conversion of Amps to Volts is governed by the equation Volts = Watts/Amps

For Example, 48 watts / 12 Amps = 4 Volts

 

[Hymerkar]

Hi, we have one 75Watt solar pannel and 2 X 110amp leisure batts. We can manage without hook up for about a week if we are not driving, of course if we are moving around then the solar pannel is irrelevant. We have a TV/DVD combination, but only have it on a couple of hours a day. But, we also need to keep my mobility scooter charged. We never use the blow air heating, only the fire, but of course there is lights, and the water pump. What is very important is to realise is that the solar, (or what ever other method you use to charge) can only fill your batteries, if you only have one battery you are then limited to the storage capacity of that battery, if you have two or more batteries then obviously you can store more power. Hope that makes sense.

 

[vwalan]

as regards saving 12v power i use the old fashioned gas lights like in an old caravan. .not usefull on a hot evening . but good when we wild camp in winter. also have a catalitic thermex heater and instantanious water heater all makes a differance when saving power. cheers alan.

 

[tony]

sometimes we use candle power.
we carry gas lights just in case.
tony

 

[NicknClair]

All solar energy would be a tragic waste unless you have the battery capacity to harness it! Whilst what everyone saying on here is true about the 15W solar panel (in as it is as useful as an ashtray on a motorcycle), having a good size panel (say 85W plus) is fine, BUT if the sponge (i.e your battery) is a small size, you won't be getting the full benefits of solar when mother nature is doing her thing and producing all of this lovely free (or not so as you still have to buy a good panel and batteries in the first place ;-) ) energy.

During the nice summer months, you are more likely to be walking/cycling/kayaking etc etc, whilst the van is unattended. This is the time when the solar is at it's best as you are unlikely to be using more power than the solar is putting in. Now if you are only running with say 1 x 85amp leisure battery, the solar more than likely will recover this in a short space of time. However if it then comes to the evening and you are watching a film on TV/couple of lights/water pump (even some of the more modern fridges use 12v even when sswitched over to gas), your 85Ah lesiure battery is not going to last long.
When customers come in for conseltation and it is established that they are more "Wildys" than EHU people, we always look at power in the form of a pyramid. The foundation stone is always leisure batteries, if this hasn't been delt with first all of the money on solar/advanced charging/portable genys is quite frankly a waste if you do not have the storage capacity to harness the power created.
Pending on if you use inverters or not, I tend to suggest a AH capacity of a minimum of 170ah (say 2 x 85ah batteries) as this covers the majority of 12v users that don't use the 12v heavily like the use of inverters etc. That way you have a large "sponge" to draw in all of the energy during the day when you are typically not using it, leaving you with plenty during the evening for the 12v items.
If you are an all year round Wildy, it is also worth having a back-up plan should mother nature not be on your side in creating enough power and to also bear in mind that you will be using more in winter (heating/ longer nights watching the TV/ more lighting). This can open a whole debate on what is the best back-up to have and everyone has the own poisions, so I will leave this one alone in as much as I don't use a geny, but have a very good alternative.

To summerise ;-) Solar energy is brill, so long as it's a good size panel, you have the conditions to produce the energy and have the storage capacity to harness it.

 

[vwalan]

nickj is correct .as well as 3x80watt panels i have a 600amp battery bank. some of you will suffefr because of weight issues. but forget those little panels ,its better to save as much power as you can. or try to cut down where ever you can.

 

[mildred]

its better to save as much power as you can. or try to cut down where ever you can.

So true - wise words. One of my jobs is to manage a substantial off-grid system, and the most significant improvement has been to micromanage wastage and to improve storage regimes by optimising charging parameters.

It's a world apart from a PV panel on the roof of a van feeding a 12V battery (of some sort ) or two - but there's a universal truth in there.

Mild Red

 

[jamesdgant]

Hi Tony

Agree with other posts - minimum panel you should be thinking of is an 80W.

We fitted 2 x 40W panels (from ebay) last year along with 2 new x 113AH batteries and find this setup perfect.

Four days "off grid" 11th - 14th June north east of Inverness, with radio, TV running off inverter most days/ evenings, and our "setup" coped brilliantly - batteries back up to full charge by 9am each morning.

I see the same ebay seller is offering an 80W panel for £185 at the moment (item number 130403231598).

We did a wee blog of the parts we required/fitting process but havn't published it yet - pm me if you want a copy.

Hope this helps

Hello, am a new member and just found this post, and am thinking of fitting one of them panels off ebay that you mentioned, how has it been in the year you have had it running any problems ??
cheers for the info
James*

 

[Vennwood]

nickj is correct .as well as 3x80watt panels i have a 600amp battery bank. some of you will suffefr because of weight issues. but forget those little panels ,its better to save as much power as you can. or try to cut down where ever you can.

Ah vwalan,

It seems we have similar views. We have a reasonable 800amp bank (5 x 160) and 434W of solar (2 x 130W and 2 x 87W) with a 2.5kw inverter. We use 240v power for all items. i.e kettle, toaster, microwave, coffee machine, tv etc. This keeps us self sufficient for most of the year with only Dec and Jan being a problem. I did beef up the charging so we have 110a Sterling Pro Digital combination so charging time is reduced to a minimum.
In the winter we carry a small Kipor and have needed to use it only once in the past 2 years. We also have a 155ltr LPG gas tank. Fortunately payload is not an issue with around 1500kgs to play with.

We use our MH all year and are away for around 20+weeks. We haven't used EHU in over 3 years

 

[Vennwood]

Hello, am a new member and just found this post, and am thinking of fitting one of them panels off ebay that you mentioned, how has it been in the year you have had it running any problems ??
cheers for the info
James*

I buy a few things off Ebay so I'm not anti them. However I would caution you regarding some of the Solar panels offered there. I found a 130W panel offered quite cheaply - it was described as a Kyocera so I emailed Kyocera for some details and was surprised to learn that that were not made by them but in fact Chinese imports that gave a much lower output than the branded ones. Kyocera went on to say that there were several imitation panels for sale purporting to be branded so buyer beware....

 

[maingate]

I heartily agree with vennwood on this.

These ebay panels may put enough charge back into the batteries in Summer but may be poor in Winter.

I started another solar panel thread which you might want to look at. There are details of the British company I bought mine off. This means that if you have a problem, you are protected in Law.

When I received mine, I deliberately put it in the shade and plugged it in. My batteries (2 x 110 ah) were fairly well charged up but I saw a big difference in charge in a very short time.

Cheap is good but good is not cheap.

 

[biggirafe]

I would always caution people to look seriously at the power they actually use, Do the maths before making an expensive purchase.

Bigger is not always better. Panels are heavy and you may find yourself with a 'heavy' white elephant stuck on your roof. The loss of payload and reduced MPG may well make any large panels an expensive add on that does not fulfill the promise.

After working out exactly how many amps all our 'things' used we choose to just have quite a small panel that works well in summer but only tricle charges in winter. We simply could not fit enough panels to make any worthwile difference in winter and we did not want to lug around the weight all year for just a few worthwhile months in summer, when guess what we don't need the power.

Most of use are moving every couple days anyway so the engine will power up your leisure battery, with eperience we have decided that 2 decent batteries and replacing all the lights with LED's is a better way of ensuring you don't need hookup.

 

[Don]

All good advice, however the only thing that I have failed to notice is the advice on actual solar output. Whatever size panel you decide on then devide by 17 and that will be the average Watt output.
The best advice I was given was, 50 Watt panel + 100 aph battery per adult.
I am a solo traveller but believe in belt and braices So doubled it. never pay for extortionate EHU charges and mostly wild camp.

Hope that helps.

Don