no batteries - the Juice4halt modules use supercapacitors instead of batteries
for long backup times
only for the RTC-485 model:
For more precise performance information, please consult the datasheet.
(J4H-5V-USB)
(J4H-HV-TRM)
(J4H-HV-TRM-RTC-485)
The Juice4halt 5V module is a supercapacitor-based energy storage. It contains a bidirectional step-up/step-down converter working as the interface between the stable 5V supply rail and the supercapacitor. During charging the converter works in step-down mode and transports energy from the external power supply to the supercapacitor. In case of a power failure, the load device (Raspberry Pi or another SBC) is supplied from the supercapacitor via DC/DC converter working in step-up mode.
The Juice4halt HV module is a supercapacitor-based energy storage. It contains two independent DC/DC converters.
The first one is a bidirectional step-up/step-down converter working as the interface between the stable 5V supply rail and the supercapacitor. During charging the converter works in step-down mode and transports energy from the external power supply to the supercapacitor. In case of a power failure, the load device (Raspberry Pi or another SBC) is supplied from the supercapacitor via DC/DC converter working in step-up mode.
The second DC/DC converter is a Front-end step-down converter. The only function is converting a high input voltage down to 5.1V for the 5V rail.
The Juice4halt RTC-485 module is a supercapacitor-based energy storage. It contains two independent DC/DC converters.
The first one is a bidirectional step-up/step-down converter working as the interface between the stable 5V supply rail and the supercapacitor. During charging the converter works in step-down mode and transports energy from the external power supply to the supercapacitor. In case of a power failure, the load device (Raspberry Pi or another SBC) is supplied from the supercapacitor via DC/DC converter working in step-up mode.
The second DC/DC converter is a Front-end step-down converter. The only function is converting a high input voltage down to 5.1V for the 5V rail.
The RS-485 Interface is accessed via a 3-pole screw terminal at the inner side edge of the PCB. The RS-485 Interface is transformed and connected to the UART interface of the Raspberry Pi.
The Real-Time Clock uses a lithium coin battery for power backup when the Raspberry Pi is powered off. The battery holder is situated on the top side of the PCB.
A push-button is used as a Power ON/OFF switch, and perfectly fits into the shutdown and booting scenarios, leading to a function very typical for all laptop-power-on/off buttons or for ATX power supply soft start buttons.