UPSIC-1205 on steroids
I got myself a Bicker UPSIC-1205 UPS (Uninterruptible Power Supply ) with PSZ-1063 data link module. The UPS device is designed to provide emergency backup power for several seconds to a minute by means of supercapacitors. I'm going to use this UPS in combination with a mini PC running as home server. The idea was to provide backup power to the server for clean shutdown on input power outage.
However, I was looking to cover a longer power outage and keep the home server running until power eventually returns, but still allow a clean shutdown in case power doesn't return in time. So here is my solution:
The original UPSIC-1205 design uses four 100F supercapacitors in series connection resulting in 25F total capacity. My upgrade takes four Eaton XL60 supercapacitors with 3000F each, resulting in 750F total capacity. Ths UPS is powered by a 12V/5A SMPS and provides the same voltage and current rating on its output to the home server. Even under emergency power conditions.
Following some measurement results while charging and discharging the UPS.
Charging without load #
- Maximum input power: 60.4W (no output load)
- Charging time to 90% SOC for output ON: 00:21:54
- Charging time to 100% SOC: 00:23:22
Discharging with 5W load #
- Maximum supercapacitor discharge current with 5W load: 0.44A
- Discharge time to 10% SOC with 5W load: 01:27:51
- Discharge time to 0% SOC with 5W load: 01:37:04
- Discharge time to output OFF with 5W load: 01:43:36
Discharging with 20W load #
- Maximum supercapacitor discharge current with 20W load: 5.4A
- Discharge time to 10% SOC with 20W load: 00:23:39
- Discharge time to 0% SOC with 20W load: 00:26:07
- Discharge time to output OFF with 20W load: 00:27:55
Monitoring server software #
The optional PSZ-1063 data link module allows to set some shutdown parameters on the UPS itself via DIP switches but also provides a RS232 data link for UPS monitoring. Albeit Bicker provides its own software I decided to write one myself that is lightweight in code, extracts the maximum number of parameters, runs as a systemd service under Linux and provides a web application for parameter and status visualization. In addition the software provides also an apcaccess compatible status report for post processing, e.g. in netdata.
The service is constantly monitoring the UPS while running and will shutdown the server in case of power outage, depending on configuration, after a specific delay time or UPS state of charge level.
Source code is available on Github: ups-server.