Hello Chetan,
Could you help us share details about the power board connected with external Coin cell in J2 and what voltage is using the coin cell battery? If you could share your setup will be highly appreciated.
Could you help us confirm if you are using a coin cell battery in BT2 of KW45-LOC too? Could you help us testing using the example in the board using a coin cell battery in BT2, without the external coin cell in J2, and confirm that it is working?
BT2 is shown in Chapter 1.6.3 Figure 4 KW45B41Z-LOC Board User Manual
Did you implement software changes in the Wireless_UART example? Also, could you help us confirm which SDK version are you using?
Best Regards
Luis