I bought the Cyrix Li CT to automatically shut off my DC-DC charger when my van’s engine is turned off so that the charger won’t deplete my starter battery if I forget to turn the on/off, lit when on, toggle switch I installed in the circuit to do this manually. The Cyrix Li CT was my backup, not to mention a method to prevent any grandchildren from inadvertently toggling it on when in my van. But, the darn thing doesn’t shut off, even when my starter battery reaches 12.0 volts after 30 minutes!
My connection is as follows: From the starter battery, through a fuse (15 amps) to the toggle switch to the Battery 1 connection on the Cyrix Li CT (which has the jumper switch connected and the ground wire connected to ground but the jumper connection at pin# 25 is connected to a push button switch that only turns on when pushed and it also lights when turned on) to the Battery 2 connection (#30 output) to the 8 amp DC-DC charger, with the charger having its own grounded wire, which goes to the LiFePO4 50 Ah battery, positive and negative cables that charge that battery.
When I turn off my van’s engine no matter if I wait 30 minutes and the starter battery goes to 12 volts the Cyrix Li CT does not disconnect as I thought it would.
Being that the 50 Ah battery is isolated by the 12-12 charge and therefore can’t send any voltage to the Cyrix Li CT, does the fact that there is, therefore, less than 1.5 volts on the Battery 2 part an issue that causes this as the Cyrix Li CT must register more voltage on that end in order to work or is it something else. I’ve gone through more than one Cyrix Li CT units and both did the same.