d.light S200 Portable Solar Lantern and Mobile Phone Charger for Camping

I have long owned the smaller model which has impressed me greatly. It charges in modest light and has lasted for years of pretty rugged use. Thus I decided to risk buying this model. I thought the larger solar panel would do a fine job. Not so, in autumn and winter, when light is most likely to be used there is insufficient natural light to charge it. This despite the older model with the built-in solar panel showing a red charging light. I have been very disappointed and have had to charge it from the mains most often which rather defeats the idea of using solar power.