1. Avoid Car Battery DrainageTo prevent your car phone charger from draining your car battery, you should unplug your charger from the power source when it is not in use. Even when it is not charging anything, leaving the phone charger plugged in may drain the car battery and may deplete its power if the engine is not running, which could leave you stranded or make for an inconvenient morning.
2. Ensure Compatibility Across All Your Mobile DevicesWhen you buy a car charger, make sure that it is compatible with your phone and other mobile devices that will require charging while on the road. Though a majority of car phone chargers are compatible with the universal USB charger specifications, some of them were manufactured before the standards were put in place. Consequently, you should always carry chargers that are compatible with your devices to avoid inconveniences while traveling.
In addition, when choosing a car charger, never buy a three-no product, you should choose a product with relevant certification, and don't be confused by low-cost marketing methods
3. Avoid Degrading Your Cell Phone's BatteryYes, you can have too much of a good thing. Using your car charger continuously to charge your phone — i.e. after your phone is already fully charged — will steadily degrade your phone's battery and reduce its lifespan. Once your phone is charged up or near to a full charge, unplug it from the car charger to help maintain the health of the phone's battery. This advice holds true for the regular chargers you'd use as well as car phone chargers: Don't leave your iPhone or Android plugged in longer than they have to be, or you'll end up seriously shortening your battery life.
4. Charge Faster by Turning Off Your PhoneSome smartphones are notoriously slow to charge, but there are ways to speed up the process if you're To increase the charging speeds while using a cell phone car charger, you should turn off your device. Turning off reduces the rate of power consumption by your phone to zero while it is plugged in hence increasing the rate of charging significantly.
Or if you don't want to turn off the phone, then choose airplane mode; when receiving SMS, WeChat or app reminders, the phone's battery will be consumed, and in airplane mode, the phone will stop signal reception, which is equivalent to being in a dormant state, so just will be easier to fill. Of course, it is faster to turn off the charging!