Nicegrover53 Posted December 27, 2012 Share Posted December 27, 2012 My wife bought me a 13w portable solar panel for Xmas (bless her). Having read previous threads I would not have bought one under 40w and as we don't spend a great deal of time without a hookup I could not warrant the expense. So do I make use of it on the occasions we do not have hookup (Last time we ran the battery out in 2 days so will it make a difference)? Take it back and get a refund? Or upgrade to a higher powered one? There is obviously a risk with the last two. If I use it and plug it into the cigar lighter can I carry on using the lights/pump at the same time or should I turn off at the control panel (it has a regulator) assuming the cigar lighter is still live. Link to comment Share on other sites More sharing options...
Tracker Posted December 27, 2012 Share Posted December 27, 2012 It is not entirely without a use! As you rarely camp non ehu it would, as you say, be hard to justify a larger panel. However what it help to do is keep either the engine or the leisure battery topped up - more or less - when the van is not in use. Your choice,as without complicating the wiring it would not only be difficult but probably fail to keep both batteries fully charged, so either the engine battery or the leisure battery? If engine you will need to find a connection that goes straight to the battery when all is switched off - if the cigarette lighter socket does you are laughing - but it may well be isolated when the ignition key is removed? Easy enough to check with a multi meter or any 12v light etc with a cigarette lighter plug. If leisure you will need to run a lead to the battery terminals to connect to. Personally I would opt to keep the engine battery charged as without this you ain't going anywhere, and they do tend to go flat in a few weeks on modern vans. Link to comment Share on other sites More sharing options...
lennyhb Posted December 27, 2012 Share Posted December 27, 2012 Agree with Rich a 13W panel is really only any good for keeping the engine battery topped up when the vans not in use. Link to comment Share on other sites More sharing options...
Frankkia Posted December 27, 2012 Share Posted December 27, 2012 Have got to agree - 13W is 1amp on the brightest day of the year (At mid day). So saying it is the middle of summer with 18 hours of daylight giving on average 1/2 amp per hour = 9Ah. So you could watch tv from 10pm to 1 am. Or at this time of year you could light an LED torch for 1 hour. I would go for the direct connection to the engine battery to keep the alarm or other phantom battery drains form knocking your battery flat. Link to comment Share on other sites More sharing options...
Clive Posted December 28, 2012 Share Posted December 28, 2012 Sorry chaps and chapesses but 13W panel is really only any good for keeping the engine battery topped up when the vans not in use IN THE SUMMER. To do this reliably, especially with modern alarms and trackers etc you need a 80 watt panel to ensure confidence in the winter during layup. BUT With a small adapter to USB you can use it as a phone charger. Howzat? C. . Link to comment Share on other sites More sharing options...
Basil Posted December 28, 2012 Share Posted December 28, 2012 Interesting, I used a 13Watt panel in a briefcase from Maplin Electronics, though ours were only £39.99 in a sale, see http://www.maplin.co.uk/13w-solar-briefcase-99760 I accept we only use in the summer and only to leisure battery, whilst on rallies with no hook up at all we find that it kept the battery easily usable for over a week. So impressed was I that I have bought a second one and use the two together chosing not to have a hook up when it is available and when on Aires in France. They are easily stowed away in their own case, as is their design, and the down side of this is they are only showerproof so no good in the rain meaning that in the UK you have to put them away when you are not around or if it rains whilst you are. Otherwise I find them adequate for our use, despite posts to the contrary. Bas P.S. We are all LPG so we only use the 12v control systems and our lights are LED. Link to comment Share on other sites More sharing options...
Tracker Posted December 28, 2012 Share Posted December 28, 2012 The simple truth is that 13 watts would only be achievable in full and direct bright sunlight and most unlikely never from behind glass. This means that all the while the panel is not directly aimed at the sun,or the sun is not 'available', or the panel is behind glass it relies on daylight alone to generate. At a guess in poor daylight the daily charge rate would be something like 2 or 3 watts for something like 7 hours a day and in high summer at a guess 6 to 10 watts for say 15 hours? That will give you about 1.5 ah of power over a winter 24 hour period, and something like 3.0 ah in summer. Most modern leisure and engine batteries have a discharge rate of between 100 and 300 milliamps due to all the electronic gubbins they are connected to so just to stand still you would need something like from 2.5 to 7.2 ah worth of daily charge. On that basis to be absolutely sure of keeping both batteries fully charged all year round, as Clive says, an 80 watt panel would be needed, together with split charge regulator linked to both batteries. We have been using a 50 watt panel for the last four years and that has proved enough to keep all three batteries well charged - but then we live in sunny Norfolk!! Probably easier for most people to leave the van plugged into the mains at home and rig the on board charger to charge both batteries? Hope that helps? Link to comment Share on other sites More sharing options...
Nicegrover53 Posted December 28, 2012 Author Share Posted December 28, 2012 Thanks for the replies. I'm not expecting much but as I have it I might as well give it a go (encouraged by Bas's post as this is the system I have). I won't be able to use it to top up the vehicle battery whilst stored though as I will not be able to leave it outside due to it only being shower proof. I should have said earlier I have a cigar lighter socket in the lounge attached to the leisure battery. Which will be easier to use than directly connecting to the battery. Hopefully on a summers day I may get an extra few minutes life. Link to comment Share on other sites More sharing options...
Basil Posted December 28, 2012 Share Posted December 28, 2012 Wouldn't disagree with anything said technically, however ours definately work for us despite the theory! So Nicegrover53 I would suggest try it, that will keep the peace with the 'better half' and if you are happy with it all so well and good, if not you have the proof and reason to buy a bigger one! Bas Link to comment Share on other sites More sharing options...
tonyishuk Posted December 30, 2012 Share Posted December 30, 2012 I would not be too despondent about your Chrissy Present :-D As Tracker and Clive had said great little tool to topping up anything that has a USB type charger ! Ipods, telephones, tablets (as in Ipad !) , cameras, Sat Navs, the list is endless, torches Rgds Link to comment Share on other sites More sharing options...
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