Cheap items can be just as annoying. We bought a lawn strimmer for about £35 about a year ago, and it was battery powered. The battery had two LEDs one green and one red. A little sticker said *both* these lights will come on when the battery is plugged in to be charged, and they do not indicate how charged the battery is. Also, do not overcharge it or allow the battery to become completely discharged or the battery will fail.

In summary:
i) You cannot tell how near to fully discharged it is
ii) You cannot tell if it is fully charged
iii) Going too far in either direction will wreck the battery.
iv) Although it shows every sign of being designed to give you the information you need, someone has decreed this should be disabled.