"If the 12V1 or the 12V2 rail cannot supply sufficient current to your charger individually, you may combine the two by wiring the rails in parallel. Before attempting this, measured voltage on each rail should be the same or very close. Because we are preparing to draw relatively heavy current loads from the power supply, doubling the wiring would be advisable. The proposed solution is to connect both the 12V1 (yellow) and 12V2 (yellow w/ black stripe) rails to the positive binding post -- any two solid yellow and both of the 12V2 wires for a total of four wires. For the DC ground wire (black), bundle at least two and possibly three wires to attach to your negative post -- all ground wires are common, so the selection is immaterial.
Using the example PSU from above, placard ratings stated a combined maximum 12V1 and 12V2 power output of 300 watts, which translates to a current of 25 amps. This is below the 34 amps one might have expected, but has given a substantial increase over the 18A and 16A ratings of the individual rails. If you do elect to combine rails for higher current, it would be prudent to keep a close eye on your PSU early on to ensure it can carry high charging loads without overheating or dropping voltage."
Discussions
Best Answer 11 years ago
Maybe this will help:
"If the 12V1 or the 12V2 rail cannot supply sufficient current to your charger individually, you may combine the two by wiring the rails in parallel. Before attempting this, measured voltage on each rail should be the same or very close. Because we are preparing to draw relatively heavy current loads from the power supply, doubling the wiring would be advisable. The proposed solution is to connect both the 12V1 (yellow) and 12V2 (yellow w/ black stripe) rails to the positive binding post -- any two solid yellow and both of the 12V2 wires for a total of four wires. For the DC ground wire (black), bundle at least two and possibly three wires to attach to your negative post -- all ground wires are common, so the selection is immaterial.
Using the example PSU from above, placard ratings stated a combined maximum 12V1 and 12V2 power output of 300 watts, which translates to a current of 25 amps. This is below the 34 amps one might have expected, but has given a substantial increase over the 18A and 16A ratings of the individual rails. If you do elect to combine rails for higher current, it would be prudent to keep a close eye on your PSU early on to ensure it can carry high charging loads without overheating or dropping voltage."
( "Current Modification", Murray State University, http://web2.murraystate.edu/andy.batts/ps/Current_Increase.htm )
Answer 10 years ago
Thank you very much, This is exactly what I needed to know. thanks, thanks, thanks
11 years ago
I think cyberguy91 said it best I'm just curious what you need 12v @ 30a for it sounds fun.
Answer 10 years ago
I'm building a Hydrogen Home Heating unit. I need about 25 amps dc.
Answer 4 years ago
me.... i need that 25 amp for my mobile radio