Battery to battery straight wire of current?

[DocZaius]

While I was looking at an example of the Biot-Savart Law for a finite, straight wire of current, I started considering whether one can easily create one in practice.

If I hooked up the positive terminal of a 9 V battery by a resistance to the negative terminal of another 9 V battery, would there be a steady current? If so, if I then tested the space around it with a magnetometer, would I roughly get the magnetic field intensities around the wire that I'd expect from the math?

The main issue I see with a battery to battery hookup would be the fast accumulation of charge in one of the batteries - which isn't an issue for a circuit current from a single battery (the battery itself remains neutral in that case).

I understand this question is more practical than theoretical, and I apologize if it's asked in the wrong forum.

 

[Gordianus]

Yor system wouldn't work because it isn't a closed circuit. Charges will pile up at the end of both batteries (in a short time) and there will not be a steady charge flow (current).