[Galaxy 3 General] nrk_2k:
FYI, you can't change the voltage of a battery unless you are adding or removing cells. If you are not doing this all you are doing is using a portion of the available voltage. So you might want to do a bit more study into batteries. A battery that has a rating of say 2000mAh is able to produce 2000mA for an hour (before being fully discharged), no matter the load, or the percentage of the voltage being used, as this is the maximum current that can be drawn from the battery over an hour before the battery is discharged. So saying a 1600mAh 12v is better than a 2000mAh 8v battery is wrong, as with a load that requires 8v, the 1600mAh 12v battery will still only be able to produce 1600mA for an hour. Using less of the batteries total possible voltage does not increase the amperage the battery can produce over that hour, it will still only produce 1600mA in an hour, so if you still draw the 2000mA, the battery will last less than an hour, regardless of the fact that it is 12v. Yes a 12v 1600mAh battery can support a higher wattage component for an hour, but only if that component uses 12v, if it was say a 6v component, but still drawing the full 1600mA, the battery still only lasts an hour.

To help people understand why this is so, here is a brief breakdown of how a battery gets it's voltage and amperage ratings.

A battery is a group of cells, connected together electrically. If we say that a single cell produces (for ease of understanding I'll only use whole numbers) 2v and 1Ah. If we want a 6 volt battery, we need to connect 3 of these cells, in series, getting a battery with a 6v rating, and a 1Ah rating. Now if we were to connect these 3 cells in parallel, we would get a 2v battery with a 3Ah rating. Now if we were to take both batteries, and connect up a load that requires 2v, and draws 3A to each battery, and timed how long the battery took to fully discharge, we would find the 2v battery would last an hour, but the 6v battery only 20mins. This being because voltage is the potential difference between the poisitive and negative terminals on the battery, the amount you use of this voltage does not change the fact the the battery still has a set potential difference. So even though both of the batteries we constructed would both have a 0 load Wh rating of 6Wh, our 6watt (2volt) load still drains the 6v battery in 20 mins. It is because of this that you always match the voltage rating of the battery to the circuit, as having a battery that you are not using the full potential (voltage) of is just like having a v8 engine in your car, but only having some of the cylinders connected to the drive shaft, so you are still using the same amount of gas (amps) but only using part of the potential output (voltage), it's just a waste (the excess potential just wasting away as heat).

As for undervoltage not affecting performance, this is not true. As each cpu has a different minimum operating voltage (for a set frequency) each individual switch inside the CPU has a different minimum voltage as well. If you go too low you may not notice a performance degradation in a stress test, or even during normal operation, but when you use a program that uses the switch which isn't getting enough volts, you will end up with errors, or performance problems (switch only operates half the time). So again I would only look at undervolting if you need to reduce the temp of your cpu (at the non overclocked speed)