How do I 12V?

[Dr. KillGood]

How do I make 7.2V into 5V(regulator)and 12V?

Don't know how I can make it any simpler then that?

[bicostp]

It's not advisable to step the voltage up. On top of the wasteful transformer you need, you'll also increase power consumption. (The extra power has to come from somewhere.) In other words, you'll drain the batteries faster.

A 7805 may or may not work with a 7.2v supply (I forget its cutoff voltage), but a switching regulator will waste less power and may have a lower required supply.

I think you're better off working with 12v worth of batteries and stepping that down to 5 for whatever it is you need to power.

[Dr. KillGood]

It's not advisable to step the voltage up. On top of the wasteful transformer you need, you'll also increase power consumption. (The extra power has to come from somewhere.) In other words, you'll drain the batteries faster.

A 7805 may or may not work with a 7.2v supply (I forget its cutoff voltage), but a switching regulator will waste less power and may have a lower required supply.

I think you're better off working with 12v worth of batteries and stepping that down to 5 for whatever it is you need to power.

Sounds simple enough.