Auto off: Metz 32 CT 3

These flash are rather very good and I have three of them for 15 Euros. The only feature that I really hate is the Auto Off after 5 mins esp., when I mount them on a stand with umbrella and it turns off after 5 mins.

Is there any way to turn this feature off?

I cannot find anything in the manual that mentions the ability to disable this auto off feature. http://www.cameramanuals.org/flashes_meters/metz_mecablitz_32_ct-3_1.pdf

In-fact in the manual they praise this design, that saves the batteries. :-(

Its powerful flash for €5.00 but...