Car alarms with indication of battery charge and fuel on the key fob

Battery and fuel charge indication

— displaying information on the battery charge level and the amount of fuel in the tank on the key fob display makes it easy to control the condition of the car without opening it and without using on-board monitoring systems. Note that before purchasing such an alarm, it's ok to clarify its compatibility with a particular car — especially when it comes to a low-cost or old car.