I sent you the manual regarding Post #1, as he did not leave an e-mail address on his profile. You will note that there are two versions. They are pretty clear in the second version that A.C. is not to be used on the supplied D.C. cable. If the supplied D.C. cable is correct, the white conductor should correspond to center positive. Since some battery chargers actually do impress an A.C. voltage or ripple in addition to D.C., that and connector size are a very good point. I did say "Theoretically", not practically regarding the one from "Batteries America", cable of supplying 300mA compared to 200mA or 250mA minimum. With an output voltage of 12 V.D.C., it should* be safe to say that the voltage to the internal regulator *under load* should not exceed 16 V.D.C. Since I own one of the *variable supplies* mentioned, I have examined the output with an oscilloscope. The A.C. ripple of the B & K 1610 which I own is nearly undetectable. *Theoretically, that is. A 'load tester' could be constructed easily following ohm's law. 12 V.D.C. divided by 300mA ( .3A) means than 40 ohms or more should be the load, at less than 5 watts. If that load reflects more than 300mA current or more than 14 V.D.C. under load conditions- the "Batteries America" supply might not be appropriate. More resistance could be added, outboard to the analyzer. If the initial specifications of 200mA ( or more! ) are correct, 60 ohms should be the correct series impedance of the system. Then two 47 ohm resistors in parallel to each other, yet series to the circuit could be connected for charging.