I look up at the clock on my wall as I type this. Once upon a time, people ( generallythe male, while the females clucked at him to be careful!) would pull up a stool and climb on it, and wind up the clock each week. Now, I pop in one of these little magic cylinders, and the clock quietly and faithfully shows the right time for more than a year after I do so.
I can take along my mobile phone, my landphone all over the house, my little music gadgets, and my MLC...knowing that these, too, will not fail me as long as their little juice-supply has been ensured.
In fact, even the power supply in my car depends on them, and for two years, at least, I can depend on being mobile as long as I have them installed and cared for... They power my home, too, when the regular power fails; they light up the processions that wend their way around the city.
I still do not know WHY they are classified as A, AA, AA, and so on (yes, I know, I should google for it.) But they are, surely, amongst the most useful of human inventions.
If only they could also be disposed of in as safe a way as they are manufactured....or to ensure that they do not die on you precisely when the need is greatest!
My little and large batteries...this is my word of thanks to you. You ease my life so unobtrusively...