Only the battery in the manipulator. The controller uses a capacitor bank as a Uninterruptable Power Source (UPS). The UPS stores enough energy to allow time needed for the CPU to image memory to storage when power is removed. The capacitor bank is quickly recharged and usually lasts many years if cabinet temperature is maintained below 38C.
There is a CR2032 battery in at least one type of controller, one with a DSQC639 main CPU, not certain about newer Main CPUs, or for different main CPU architectures, e.g. Compact, OmniCore, etc.
I believe its primary purpose is to support CMOS.
Here's the error that will be seen if the voltage drops too low:
37053, Low CMOS battery voltage level
Description
The CMOS battery on the computer board is empty.
Consequences
On restart, the system will use an erroneous setup or no restart will be
possible. (All that has been experienced here is a loss of date & time)
Probable causes
Faulty battery.
Recommended actions
1. Replace the CMOS battery
Oops, forgot about the 2032 in the computer unit. Usually didn't replace unless cabinet was older or it was losing Date/Time. New measures > 3.1V, always changed if it was under 3.0V. They are usually good for 8-10 years. Always had 2 or 3 in my laptop bag just because.
