Hmm, I see the dilemma, especially since it is entirely possible to accidentally get into this situation when out in the wilderness with no shop nearby to verify the correct intended number of charges remaining
It would only be a matter of time before the relevant variable wrapped around to this unrealistic figure, after which one might feel that they were somehow cheating by continuing to use the item
Perhaps it would be an idea, if possible, to change the item so that it would permanently bestow haste, or some equivalent of it, whilst wearing the item. If you think that this would make the item too powerful, then maybe this very beneficial effect could be counterbalanced by some other undesirable one. How about making the item very heavy, lowering the armour class protection that it grants or the character's hit points or stats, increasing susceptibility or damage from specific types of attack such as fire or magical damage or from certain types of monsters, something along those lines? Simply doubling or tripling the amount of magical damage sustained whilst wearing the item would make me think twice about using it
An item like that could be quite interesting because one would have to weigh up the pros and cons of using it
Regards
Chris