Sprint Nextel MOTOKRZR K1M - Manual (Page 204)

188 Section 4A: Important Safety Information
ⅷ It is normal for batteries to gradually wear down and require
longer charging times. If you notice a change in your battery
life, it is probably time to purchase a new battery.
Contact your local recycling center for proper battery
disposal.
WARNING! Never dispose of batteries in a fire because they may
explode.
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