Reply from SolarCentre:
Many thanks for your comments Adrian - good to hear you like the product. The standard batteries in the unit allow up to 3 nights of run time, any extra than this is just wasted capacity as the solar panel won't use all of that extra capacity as part of its standard charge and discharge cycle. When designing the products to work in UK conditions it's always a balancing act between the solar panel and battery capacity and from what customers are telling us we've got this balance in the right place at present. Once again thanks for your feedback and we'll be discussing this in the next product design review meeting.