On 07/06/11 1:41 PM, Ljubomir Ljubojevic wrote: > I would/will only use 12V power for direct connection from UPS battery > to ATX connector. It reduces conversion losses and power draw. if by ATX connector, you mean the one on the motherboard, a standard ATX mainboard requires REGULATED 12 volts, as well as 5V and 3.3V and -5(legacy) and -12(legacy). Your 12V battery is more like 14V when its fully charged and connected to a trickle charger, and down around 11.5V when its under load and mostly depleted. If you wanted to run a mainboard on this sort of power, you would need a specially designed mainboard with built in DC-DC supplies, or you would need a DC-DC multi-voltage ATX compatible power supply (such as previously mentioned on this thread) -- john r pierce N 37, W 122 santa cruz ca mid-left coast