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.