Different universal car chargers function in much the same way, so the main considerations when choosing one should be the output of the charger, the kind of charge it delivers, and charging time. Different car chargers have different tips, so it is also important to check that the charger you choose has the correct tips for any devices you may need it for.
A universal car charger functions by connecting to a car's auxiliary plug cigarette lighter. A standard universal car charger does not overcharge devices, and most feature a light-emitting diode (LED) indicator to show the charge status. If you need a charger that will deliver more than just a trickle charge, you should check that the charger is rated at 1 amp at 5 volts. Most chargers produce about 500 milliamps (mA) at 5 volts, which means that it might not charge a device that is being used.
A universal car charger will also offer a variety of tips so that the charger can be used with a number of different devices. Some of the devices that can be charged are mobile phones, laptops, iPods®, and digital cameras. If the charger you wish to purchase does not feature the tip you need, there is the option of purchasing additional tips. Purchasing additional tips can be cost effective, since extra tips can be had for a fraction of the price of a new charger.
Keep charging times in mind when you're looking for a charger. Some universal car chargers offer rapid charging. The downside to rapid chargers, however, is that they tend to overheat, and this can cause damage if they are left on charge for extended periods.
There may be times when you will need to charge a device but do not have access to a functioning auxiliary plug. This is when an emergency universal charger comes in handy. These chargers can be stored in the glove compartment of the car and do not need an external power source to charge a device. Normally, a single AA battery is needed to power this kind of charger, making it lightweight, and compact. Keep in mind that you need to choose an emergency universal charger that will deliver a sufficient charge for the device you intend to use it with. The best way to do this is compare the specifications on the charger and on the device you'd like to charge.