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Answer from Engineering:
The answer is NO, you can’t use this battery to power FSII Base directly. Reason for that: OLED Displays which is getting power directly from the external Power power supply have an absolute maximum voltage15Vvoltage of 15V. Our specified Power power supply (453G032-2) has 12V +- 0.5%. There are many ways to make this battery work with our Base base – regulate the battery voltage down to 12V, but It should be done outside the Base Station.
***Clear-Com does not condone this activity and will not take responsibility for any damage done to a Basebase.