I'm not knocking this lantern, but I am raising a question that this type of technology has.....
One must get a review from someone who has used this significantly, because the battery's longevity is what needs to be questioned here. Quite often, they lose chargability over time, but that is not the case with all of them. Having a portable solar light and cell charger is a great benefit, and it's why I have purchased the Biolite SolarHome for my homestead (which I am sure is a good deal more expensive at around 150 dollars, and much less portable).
As for this unit, I am impressed by several things. It is only 25 dollars, which makes it a great camping tool for the family. Flashlights just do not work great at dinnertime with friends. Second, it has a 2600 mAh battery, which isn't the hugest, but it's a nice size for a budget system such as this.
For those that like to hack things, one might attempt to put a larger battery in place of the 2600 mAh. I would venture that all of the charging circuitry was external from the battery, and it's just two leads to the
battery bank. I would think that you could replace it with any size battery (as long as you can get it to fit inside of the lantern body). I haven't opened one up, so these are just assumptions on my part.