Maplin have the 13 watt solar brief cases on offer for £50.
I bought one a couple of years ago and cannot fault it. We are usually non EHU and find that it more than copes with our useage. Actually tried disconnecting the battery last weekend to see how good the solar brief case is and found it would power a striplight and waterpump with no battery connected.
That looks pretty good!, they have a 2.5watt one for £12.99 too, I was thinking of getting the cheaper one and wondering if that will charge my battery to max when it's in the storage site?
I had the 2.5 watt one first. Complete waste of money. Bear in mind that a solar panel will not recharge a flat battery, they are primarily intended to keep it topped up during use and top it up after partial discharge through the night. The 13watt one should charge the battery from 80% to full though not convinced the 2.5 watt one would have enough gumption to charge anything much more than a few AA batteries to be honest, as 2.5 watts at 12 volts is the equivalent of around 200 milliamps. The odds are that the battery is discharging quicker than this through natural current leakage. Even the 13 watt one is little over an amp and given the voltage of the battery increases as it charges, the current decreases (Amps = Watts / Volts) Nevertheless, we find 13 watts adequate for our needs, but still go easy on the battery as with no means of recharging it those 12 volts are a valuable commodity.
We use a 13watt one each weekend we are on a rally with no hook up. It keeps the battery topped up even in cloudy weather.(So long as you are sensible with the lights and don't run a 12v tele for too long.)
I have one of the 1.5 watt ones from Maplin (Code L58BF) which I leave in the van full time whilst in storage and it keeps the battery topped up but would not I believe charge a battery from flat. I also have the Briefcase one which we use when not on EHU and that keeps us going. I have wired the control box that comes with the 13 watt into the van and the 1.5 watt plugs straight into this as well so job done.