When a supercapacitor is connected to VBB, the memory can be maintained anywhere from a couple days to a couple weeks once powered off. The CB290/CB405 consumes about 15-20mA of current when idling. For a longer backup period, a battery pack can be used. A protection diode, as shown below, is necessary when using a battery, as the device normally attempts to charge a capacitor through VBB. Due to the relatively high standby current for battery backup, it is recommended to keep the device powered if possible and only maintain battery backup for short periods in the case of an emergency.
If a Cubloc module is supplied with power above the recommended voltage, the device can be destroyed. Also please be careful to avoid electrostatic discharge, as it too can destroy the device. Please be aware that P1 is an input-only pin. To reduce accidental power drain, please set unused pins to input. All I/O ports are set to input as default at power on. When not using SIN, SOUT, and ATN, please do not connect them to anything.