Originally Posted by Ratchet
Over time, 12 volt phone chargers that are left indefinately connected either a) fail internally b) melt the power socket in the vehicle. Not all chargers are created equal either. Some can handle continuous use alot better than others.
Battery drain would be the least of my worries. Save yourself the headache and only connected the charger when needed.
A charger is not going to create enough heat at the socket to melt the power socket. Ever. In fact, it's likely fused such that it wouldn't be able to melt the power outlet even if left on forever and ever.
I'm not going to argue that the charger won't fail internally, but I will argue that the charger unplugged when not in use will eventually fail internally too. And given that the average lifespan of a mobile phone is ~2-3 years, and chargers are very cheap now that all phones worth looking at use mini-USB, there's no concern in having to replace a charger once in a while.