Turnigy Charger Regenerative Discharge on server PSU?

[iamdarkyoshi]

I have one of those turnigy reaktor chargers with regenerative discharge. It allows you to discharge the battery under test up to 20A into the source power supply, as obviously, that power has to go somewhere. However, when using a server power supply (like I do) the regenerative discharge will not work. IS there some sort of circuit I can build using some nichrome "springs" and a fan as a high power resistor, and make it so the charger discharges into that load instead of the power supply, but the power supply does not discharge into the load?

[Siwastaja]

Simple comparator comparing the voltage to an adjustable setpoint, driving a MOSFET which turns the resistors on. Adjust the setpoint above the PSUs idle voltage. When the batteries discharge, the DC link voltage rises until your comparator thing works. Beware of oscillations, though.