[b]In response to a request for help I had these views:[/b]
I mentioned a number of options to alleviate your dependence on the generator. Given a spend of £600 you could buy 250W panel, 120Ah battery and a MTTP controller and peripherals. The ones I mentioned would be very good quality. You could save 100 or 2 maybe but quality would drop.
The cheapest option is just to have more batteries so that when you do run the generator you will be storing more for the next day. However after you gave me the details of the battery charger, at 10A max. it wouldn't charge much more with another battery or two and you would still have to run it for some hours. You may be able to get similar batteries to that you have for £60 (70Ah)
My latest view is that you would be better off with a single solar panel of 100W. This would give a 8A charge to your battery every hour of good sunlight, compared to 10Amax from the generator.
I have contacted Wind and Sun in Hereford and they have a new 100W panel from India, the cost is £126 including VAT and Carriage. It has a general junction box so standard cable can be used to connect it.
A more substantial option is to buy two such panels, two more batteries and a controller and you would be unlikely to have to use the generator, but that would cost another £350. This would give you 200W input, per good sunshine hour, 210Ah battery.
The outcome as of 20th June 2015 is to buy a single 100W panel as in the penultimate paragraph above. I am encouraging the user to connect it themselves and monitor the battery charge with a pre existing voltmeter. The panel can be manually adjusted to receive maximum radiance or alternatively reduced to ensure the battery doesn't over charge. (*Once a voltage of 14.5 has been sustained for two hours the maximum should be reduced to 14.* - This only applies to a continuous charge for example from a mains charger 24/7)
Fri 7th I connected one panel, via the Steca Controller, to one old battery. Used it as load battery and measure a use of 10Ah total.
Could see from the Steca the Asus 900 uses 1 amp
Sat 8th Since then I have 2 old 50w panels connected via the Steca to one old battery. The other old battery I have topped up with water, which was a bit iffy as it was a sealed battery. The six cells needed about a litre so hardly surprising it/they were almost unrechargeable.
That battery as end of day on the 9th was rated as 52% charged, by the next morning is was 48%
Switched old battery. Bat I received 25Ah charge via Steca and was at 80% when disconnected.
Connected two old panels and one new REC max charge rate was 4.4 of 6.8 generated? Will fill with water tomorrow.
Bat 2, filled with water 2 week ago, was at 3% charged at connect. It rose to 12% at sunset, 15% by 2100 hours and 18% now at midnight. 19% at 0100 How ??????
At 0900 theSoC reads 23%??? and now at 1200 the sun is up but it is overcast 0.6A charge, 12.8v Soc 25%
Tue 2nd Dec 1140 Soc 54%
Jan 1st 2015 Soc 61% however the battery seems to be discharging quite rapidly down from 80% two days ago. I should check there are blocking diodes in the each of the two panels.