Sue
Don't know about standards so we can only speak for the Air Shields TI 1500.
For that the test parameters from full charge (10hrs for one battery and 20hrs for two) are as follows:
Set Point 36C - 11C Ambient
Operating time (Full heater, all heater lights on) 90mins for 1 battery and 3hrs for two.
Batteries are 12V 24Ah.
Hope this helps.
smile