yes 9 months and it will still work good, depending on lots of things.
if its protected or not
if its a good cell (or a cruddy one)
how long it has aged, in about 3-7 years it will be dead, so a primary cell might be a better long term choice , rechargables like to be used
there is some voltage depression when loaded , if it has not been cycled for a LOOONG time. so if you maintance it every 6mo it would work more like it did when used.
and most importantally when making a determination like this is YOUR actual results in your actual device with your actual battery, some devices will discharge a battery very slowly, some protections will discharge it very very slowly, and some conditions a battery is put in are not good for them. so it wouldnt hurt if you checked this stored item, see how things are working out, then make any changes based on what you find.
of all the rechrgables the li-ion is a champion of staying charged , and not being depressed, but there are always many other factors.
if 9mo later you drag the thing out , and its gone below spec from discharge, then it can get ruined
because the voltage is easily read, and can determine a lot about the discharge state of a li-ion, a few checks of it here and there, and you would KNOW .
