Power Supply volts
 

I'm not electrically educated so bare with me.

What does the output voltage of a Power Supply have to do with anything?

If I have 2 500 watt power supplies, and one is 12v output and the other is 18 volt output, what is the advantage of the 18 volt unit? (see, told ya') lol

Voltage x amperage = watts. The more watts, the more power. Make sure your charger is 18v capable though.

So according to the calculation of Voltage x Amperage = watts that means that the 12v 500w power supply only puts out 42 amps and the 18v 500w power supply only puts out 28 amps does that make a difference in the performance of your charger? Does amperage make any difference on how a charger will perform? What is the lowest recommended amperage you should ever go down to on a 12v power supply? Just wondering seeing as my computer converted power supply is d.c. rated for 160w output but at 12v it has a maximum of 11a max, accoring to the formula I get 12v x 11a = 132w so what does that mean that the manufacturer doesn't know what the actual watts rating is or am I missing something? Is that enough to run a 50watt 5amp charger? With this power supply what is the biggest baddest charger I could use on it? Could I use it with a mutiple battery charger? or would I have to get a more powerful power supply?

Computer PSUs have more power rails with different voltages; the 160A in the spec is the combined performance over all of them. Any individal rail is lower than that. Luckily they give off the most power over the 12V rail.

To the OP, the PSU output voltage must be within the acceptable range of your charger and the output power should be about 10-20% higher than the required power for charging your packs. That 10-20% depends on the efficiency of your charger. Generally if the input voltage is higher than the voltage of the packs you are charging then the chargers work with higher efficiency, so they consume a bit less power and will stay cooler.