The simplest truth about phone chargers in cars is you get what you pay for. To elaborate, the better the phone (usually more expensive) and the better the phone charger in your car (more expensive) the more reliable the phone charging will be. You will get a safer, faster, and more reliable charge from a more expensive charger. Secondly, the reliability of a car phone charger depends on how the charger connects to the power supply (battery) in the car. The lifetime of a car phone charger and prevention of damage to your phone from a car phone charger depends on how much you pay attention to charging your phone and how well you keep your car’s electrical system maintained.
There is a voltage regulator in a car phone charger that converts the 12 volt DC (direct current) to five volt current that most phones use to charge the battery. The voltage regulator in cheaper phone chargers can break in several ways and allow the full 12 volts from your car battery to go to your phone. This will probably damage the phone partially or at least burn up the battery.
The reason cheaper phone chargers for cars fail is the voltage regulator converts excess voltage into heat. The plastic that covers the voltage regulator in some car phone chargers will split or melt under current if you use the charger a lot. If this happens the full 12 volts from the battery will go to your phone. This happens because the failed voltage regulator in the car phone charger has become a direct line into your phone.
More expensive car phone chargers have a fail safe device that senses when the voltage regulator fails and will cut power to your phone and keep your phone from damage.
Most car phone chargers connect to the power in the car through a plug in connector to the cigarette lighter or directly to the power through lines in the cab of the vehicle.
If you leave your car phone charger on all the time, the phone charger will not last as long as it should no matter how expensive the device is. You should look for a car phone charger that has an on-off switch or disconnect the charger from the cigarette lighter when not charging the phone. As long as the charger is getting power the voltage regulator is getting hot and the more time this little component stays hot the shorter life time the car phone charger will have regardless of how much it cost.
The Phone and the Car
Most phones have an automatic charging cut off built into the phone. The problem is that the auto cut off does not know when the phone battery has lost power. Batteries lose power just sitting in the phone. Checking the power on your phone and not leaving the phone in the charger is the simple solution.
Cheaper car phone chargers that connect to the cigarette lighter are inherently more likely to fail because there are more components in the device that can fail. Direct connection to the battery is more reliable and usually safer.
The lifetime of your car phone charger depends on how well you maintain your car’s electrical system. The fluid level in the battery, the connections to the battery, and the fuses that limit power to the devices in the car should be checked monthly. Poor car performance and faulty wiring to the battery can damage both the car phone charger and the phone.
Car phone chargers work. The truth is the more expensive models work better. The newer and more sophisticated your phone is the less likely it is that the phone will be damaged by the charger because the phone is “smart”. Most car phone charger success depends on the user paying attention to the charger, the connections from the car to the charger and the phone, and maintaining the car’s electrical system.
By Andrew Handley I write about cars and driving at an automotive website. You can read more on my blog.