Dump Backup Battery

[BrianBSL]

Originally Posted by billbo911

One other device that gets it's power from the "backup battery" that hasn't been mentioned in this thread is the CMUcam2. With the extra focus being placed on this device in CD right now, it would be good to remember that as well. I don't know for certain that we will be using this camera this year, but my guess is we will.

As far as using the 12v battery to drive a 7.2v supply as a means of eliminating the backup battery, forget about it. The only way to do this and still get 7.2v out of it even when the main battery drops below 7.2v would require a circuit with weight and size that exceeds that of the backup battery it's self.

Huh? What is preventing you from doing it with an IC based buck/boost converter? Small surface mount IC plus an inductor and a few resistors is all I could see that would be necessary. I'm certinally no expert on power electronics, but I don't see what you would need that would be "a circuit with the weight and size that exceeds that of the backup battery".

Not that I would say its worth doing it, stick with the backup battery. If you are really worried about size/weight, there are plenty of suppliers of smaller premade 7.2V battery packs.