solar emergency lamp good

i bought a solar emergency lamp from amazon for about rs 400.
it has a small solar panel on top. led lights and a cap which can be
pulled up to put the light on and pushed back to put it off.

working nice for the last one month or so.
it can charge from mains too. and has a  usb port to charge mobile phones.
i haven't tested these facilities yet.

how long the battery which is surprisingly light weight will last is
the only worry.
yet it is a good try

here are some photos