ePower Lion EP-450P5-L1

Written by Stan Bloch in on 4 August 2004. Page 1 of 2.

The EP-450P5-L1 is probably the best all-round PSU (Power Supply Unit) from ePower. It has many of the features which one would consider to be in a good PSU, in addition to other features which ePower offers. Silence is one of the most important features of this power supply; this unit is inaudible which is ideal for silent systems.


A sticker from the side of the EP-450P5-L1 provides a good summary of the technical specifications of the whole Lion family:


Enhanced VGA Power Lead:
Enhanced VGA Power Lead, a patented special feature of the gaming power series. The VGA power lead comes with a RMI filter and wire coat to eliminate the EMI (Electromagnetic interference) effect on VGA cards, thus no more snow and water wave effects. A great plus for PC gaming.

Power Fan Control Switch:
The Power Supply fan turns on automatically after reaching higher than a 250W load, or the user has the option to turn on the fan at anytime.

SATA Power Lead:
Two SATA (Serial ATA) power leads can be found on all ePower Technology’s gaming power supply.

Case Fan Speed Control:
To maximize the silent effect of ePower Technology’s silent technology, all ePower PSU’s are equipped with three special power leads for case fans. These leads will reduce the power sent to these fans, depending upon temperature, to have a good ratio of cooling to silent performance.

Temperature Sensor:
An amphibian temperature sensor lead comes out from the PSU to the chassis. The temperature sensor, together with the chassis fan lead, will regulate the case fan speed when the internal temperature rises above normal operation temperatures.

LED Fan:
A blue LED fan can be found inside of this ePower PSU.


∙ Velcro and zip straps
∙ US only power cable
∙ Manual


Following my legacy of inspecting the insides first, we took the unit apart as soon as we received it.

These pictures show the big heatsinks that cool the switching components. One heatsink is so big it sticks out the back. If a non-silent fan was to be used this kind of cooling would be considered excessive. Some 550W PSU's get by with much smaller heatsinks, while remaining quiet.

The build quality is very high with just about every cable end covered with heat-shrink. One thing that stands out is what I think to be the PWM (Pulse Width Modulator).

The PWM controls a switching transistor. This transistor is probably attached to one of these heatsinks as it has to work hardest of all the components in the PSU. Its job is to control how much the main inductor is charged. If a PWM is wrongly calibrated or has poor build quality, the output voltages will sway.

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