I have a 13 year old IC735. In the manual it says the
lithium battery is good for 5 years. After that it
should be monitored closely and replaced as needed.
The battery has not been changed in the 13 years.
So I am thinking its time to replace it.

The manual says it is used for the memory that
holds the frequencies and setup. And that it should
be replaced by Icom. At this time the radio remembers
all the setups and frequenies when powered down. So it
appears to still be functioning.

What happens if I remove the battery with the power
off? Do I loss just the setup? Or do I loss the operating
system for the radio?

Thanks in advance for any information.

Derek Toeppen, WA0ZTI