Add up the power consumption (in watts) of your devices, divide that into 158, and you will know how many hours your battery will be completely depleted from a full charge.
The ASIAIR alone can take up to 15 watts (typically 3 watts when it is not doing anything, and with no devices connected to it), the energy usage of your mount will depend on how often you slew (tracking typically takes just 5 to 10 watts), each dew heater could take 5 to 20 watts, and the camera's cooler could draw more than 35 watts, depending on how far you push it. The large camera electronics itself can draw more than 5 watts from the USB port, so you need to include that too. A guide camera takes about 1 to 2 watts. Focusers and filters wheels are seldom active, so you can disregard them.
Just look up the specs of each of the devices that you have and compute it (or just measure it). It will be different for different people, so there is no universal answer. The power consumption is no more than 25 watts for a very simple set up, and over 50 watts for more serious set ups.
Chen