It is often convenient to be able to charge phones and many other devices that can use cables linked to USB sockets for charging.
Sometimes cars or vehicles may not be fitted with USB connections, or it may be that a variety of devices need to be charged using a USB charger whilst on the move in a vehicle.
In many instances, a USB charger that takes power from the vehicle's cigarette lighter power socket can be invaluable.
Knowing what to look for when buying a car USB charger is key to making sure you make the best buy.
What is a car USB charger?
A car USB charger is a small adaptor that plugs into the cigarette lighter/accessory port found on virtually all cars and provides one or more USB outputs.
As the cigarette lighter/accessory port provides a nominal 12 volt output, the car USB charger converts this voltage to the 5 volts required for the USB supply.
Also as the car 12 volt supply can vary considerably and also have spikes and surges on it as a result of the other car electrical systems. The car USB charger needs to protect against these so that anything connected to the USB port will not be damaged by this.
In its basic form the car USB charger can be used to charge a host of devices from smartphones and tablets to power banks and even certain models of camera. It is worth remembering, though, that the cigarette lighter/accessory port on the car is only active when the engine is running. This is done so that the car battery cannot be discharged accidentally by leaving a heavy current appliance in the socket.
Some car USB chargers can contain a lot more functionality, acting as a connectivity hub - some are able to connect to music players including mobile phones and radiating an FM signal to be picked up by the car radio. This can be very useful if no USB functionality exists in the car. They may also enable hands-free phone calls to be made.
These car USB chargers are very useful when smartphones are used as satnavs with applications like Waze as they tend to use a lot of battery as the screen is live all the time. Also they can be useful for keeping batteries for the tablets etc used to keep the children happy on long journeys.
What to look for when buying a car USB charger
There are a number of points, hints and tips that can enable the best car USB charger to be bought.
- Multiple sockets: Consider what you might want to charge. How many devise are you likely to want to connect at any one time? Most car USB chargers have two outputs, and this is often enough, but if there is a possibility of more being required, then car USB chargers with four outputs are also available. As the cigarette lighter/accessory ports are often located near the gear lever or other controls for the car, be careful not to have too many leads in this area. In some cars, there are power ports behind the driver, in the back seats, etc. For keeping children occupied on long journeys, a four port car USB charger may be more useful here.
- Size: It is worth considering the size of the car USB charger. This can be important if the 12 volt lighter / power point is located close to any of the driver controls. Check that any USB charger will not obstruct anything, and the leads can also be routed away from the vehicle controls. Some of the chargers with more outlets and more functionality have to be larger and often taller. Check that any device can be accommodated easily.
- In-built lead: Some car USB chargers come with a lead already built in as part of the assembly. Although individual requirements vary, this does not appear to be a good idea because the lead needs to have the required connector on the end. This limits the number of devices that can be charged and may render the charger useless if the phone is changed and the new phone has a different connector. Even if a USB socket is provided, the lead can become a nuisance if it is not in use. Also leads are the first things to break, so an inbuilt lead can quickly render the charger useless, or if there is an additional USB socket, it can mean that there is a broken lead permanently attached to the device. So from this point of view chargers, my view is that chargers with in-built leads are not a really good idea.
- Power output: Not all the outputs on the car USB charger may be the same. Check the current capability they provide. Often they provide around 2.1 or 2.4 amps dependent upon the device, but check what you need.
Car USB chargers providing 2.1 and 2.4amp are now common. Its important to get one with a good output as a charger that is lower rated than the device requires means it will take longer to charge. Make sure that the output is available on all the USB sockets. Some chargers may only have a high output on a limited number of their outputs, so check the small print.
The newer smartphones and tablets can consume more power to charge them as the batteries are larger. It is best to check the details on the wall charger provided with the phone and then ensure the car USB charger that is bought has at least one socket with the required output.
Smartphones are ideal for use with apps like Waze, etc that provide driving instructions. The constant screen usage combined with at of the GPS that needs to be constantly updated drains the battery faster than usual. This means that it is particularly important to have a car USB charger that can provide sufficient power to power the smartphone. A typical 2.4 amp capability should be sufficient in most cases, but it is always best to check.
- Fast charging: Most of the latest smartphones incorporate a form of fast charging. There is the Qualcomm Quick Charge Samsung Adaptive fast Charge and Apple PD. These standards enable a much faster charge to be obtained, whilst not unduly degrading the long term performance of the battery in the device. As the Qualcomm Quick Charge standard is used across a variety of smartphones, this one is found in some car USB chargers. Check what your phone supports if you want a fast charge capability.
- Quality: The term quality can be a particularly vague term, and one which is very hard to assess. Often the popular brands or those with good review ratings will best. It is worth thinking about the cost. Although this is not a complete indicator, the exceedingly cheap ones are unlikely to have all the testing and safeguards in place. After all, the better brands have a name to protect, so that are likely to make sure their products are reliable and conform to the right standards. Would you trust you really expensive smartphone on a car USB charger that costs just a dollar / GB pound / Euro? It is worth spending a little more for peace of mind and the better quality you are likely to get.
Don’t buy cheap car USB chargers of dubious quality - these are likely to compromise on certain safeguards that other models provide for handling the fluctuations in voltage that occur around car electrics or for taking care of overheating problems. It’s just not worth it.
There is a huge variety of car USB chargers on the market. Fortunately most of the reasonably priced chargers are reliable and provide excellent performance. Provided that you don’t go for the exceedingly cheap ones available and you select one that has broadly the right functionality and capability, then it is likely to give good performance. Bear in mind points like accessibility, likely reliability, built in leads, and output capability and all should be fine. Also if you need additional functionality, again, don't go for those that are too cheap, and check the functionality is exactly what you need.