Problem: saving lcd values and scrolling through the saved data

I am using arduino atmega 1280 to measure and display voltage, current, temperature and time of a 12V car battery in use in a car. I would like to save the displayed data and be able to retrieve it at the press of a button connected to one of the arduino pins.
Any assistance offered will be highly appreciated.
Thanks

I would like to save the displayed data

Save it where? How much of it?

and be able to retrieve it at the press of a button connected to one of the arduino pins.

For what purpose?

Any assistance offered will be highly appreciated.

You haven't asked any questions. I did, though.

The reason for measuring the V, I and temperature of the car battery is to keep track of its performance and in the process know its subsequent failure point. I would like to save the data on an external flash disk.
Thanks.