There are many small electronic items that can be run off of a 12 volt battery.  If you have a car, you can use the car battery in an emergency as a charging station.  Here is a list of some things you could recharge from a car battery.

Cell Phone
Battery Charger (AA and AAA batteries)
E-Book Reader
I-Pad or Tablet
Nintendo DS or other electronic game
Anything with a USB or Cigarette Lighter Charger

All you will need is two adapters and one monitor to give you feedback on the condition of your car battery.


FirstRoadpro 12v Battery Clip-On and Cigarette Lighter Adapter  Adds an external cigarette lighter socket by connecting directly to car battery terminals. Currently $5 shipped.


You’ll want to do your recharging directly from the battery. Charging through the cigarette lighter outlet inside the car with the ignition key in accessory position will use more battery power.



SecondSaicoo 3.6A/18W  Rapid Car Charger  Expands 1 cigarette lighter socket to 2 and adds three Hi-Speed 3.6A/18W (total) USB ports.  Currently $13 shipped.




ThreeMini 12V/24V LED Display Digital Car Volt Meter

Displays the condition of the battery and charging system.

For 12-volt negative ground systems.  Easily plugs into a cigarette lighter socket.  Currently $6 shipped.



Most items that can be charged through a lighter socket or USB port do not draw much power from the battery.  In most cases you don’t even need to have the car running while charging these items.

It is important to monitor your car battery and make sure the battery doesn’t drop below 75% of its capacity. Once it hits 80% of its capacity you’ll need to turn on the car and let it idle in a well ventilated area until the battery is recharged.


Make sure all the devices you were charging are disconnected from the battery when you start the car.  Once the car is started you can reconnect the devices and continue charging them while the alternator recharges your car battery.


How do you know when your battery reaches 80% of its capacity?  Use the Digital Volt Meter and the following chart.  It is based on  Open Circuit Voltage which is measured when the engine is off with no loads.  Deep Cycle batteries have slightly different charge and discharged properties.

Open Circuit Voltage for an Automobile Battery

12.6 + Volts- 100% Charged
12.4 Volts – 80% Charged
12.35 Volts – 75% Charged
12.1 Volts – 50% Charged
11.95 Volts – 25% Charged
11.7 Volts – 0% Charged



Ed Rogers
Copyright “Keep It Simple” 2013. All Rights Reserved.

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