What is the best way to charge a Lithium ion battery for maximum battery life?

I recently bought a new cell phone with a lithium ion battery. The sales person said I should plug it in every night regardless of how much I use it. My previous cell phone's manual said to occasionally completely discharge the battery before charging. I do not recall what kind of battery it had. My new cell phone manual dosen't mention anything at all about charging. Should I fully discharge the battery before charging or is it safe to charge nightly and still get a long life out of the battery?What is the best way to charge a Lithium ion battery for maximum battery life?To make your batteries last the longest: first time charge is usually overnight as it is slow as heck...HOWEVER you DO need to condition your batteries at the beginning, and every 2-3 months for optimal performance. To condition a battery - let it run down to DEAD DEAD DEAD then recharge fully on a wall (plug in) charger. Do that 3 times in a row. Do NOT use your car charger to condition - every time you stop your car and restart that interrupts the charging cycle and is hard on your battery. For the same reason never leave it connected to your car charger continuously. If you want max life, don't expose to freezing or overly hot temperatures as rapid temp changes and overheating can shorten battery life. That goes for both ni-mh and li-ion batteries. You had it right the first time, so keep doing what you did with your 'old' battery. The only time I 'top off' mine is if I'm going to be going somewhere there is no charger, or I expect to use my entire phones' power supply while out of the house. Other than that, it goes dead to one bar before i recharge. my battery is 3 years old and going strong.What is the best way to charge a Lithium ion battery for maximum battery life?With any battery you should occasionally discharge the battery before recharging. But with this type of battery it can be recharged nightly. I usually only charge my battery when it gets low.