With all Li ion and poly batteries u can charge them at anytime and not have to worry about a memory. I would recommend that you charge it as needed. And save your Car charger for those emergency times only. Also, don't charge and talk on your phone at the same time, it can cause problems with the charging bracket that surrounds the phone thus making it to break out of the phone. If that happens that will NOT be covered under warranty, as stipulated in LG's manual.
***ALSO, TURN ALL PHONES OFF ATLEAST ONCE A DAY TO HELP WITH ANY GLITCHES THAT MAY OCCUR WITH YOUR PHONE, I.E. POOR RECEPTION MISSED CALLS ECT.***
As with any phone, you don't want to do a whole lot of overnight charges. Actually, try not to do them at all unless it is a must. This overcharges the battery and takes away from the overall longevity of the battery. Your battery will begin to last significantly less and less in between charges over a few months of doing this and pretty soon you'll have to buy a new battery. I try to charge my phones in the evening when I'm eating or watching TV or something and then take it off before going to bed. You can charge your phone whenever you want...in other words, you don't have to wait for the battery to drain. But if you've already got three bars of life, realize that you only need to have the phone on the charger for a short while. Basically... (continues)