The Buck circuit interferes with the radio.
This 1.5V lithium battery can be used in other electrical devices, but it is not suitable for use in radios. Because it has a built-in voltage reduction circuit (because the lithium battery cell voltage is about 3.2V-3.7V, the voltage needs to be reduced). This step-down circuit causes interference with the radio. If you want to use lithium batteries on the radio, it is recommended to use lithium iron phosphate batteries of specification 14,500.
The voltage of the lithium iron phosphate battery is 3.2 V. One battery plus one reserved space can be equivalent to two ordinary batteries. The voltage will also be slightly higher, which will improve the radio's sensitivity and speaker volume, and will not affect the life of the radio. I used lithium batteriesiron phosphate on the SR35 and the sound was louder.