I have an Icom M30. Excellent radio BUT... it will go flat in just over a week if you leave the battery in situ as there's a current drain from the 'soft' off button.
This is just outright dangerous. You need a handheld for emergencies and this CANNOT BE RELIED UPON. When challenged about this at boat shows they say it's by design and that it's to enable the battery to be exercised! This is an insult and shows no understanding of its SOLAS usage - it's not a mobile phone, it's a safety item!
Removing the battery is fine, but this then exposes the radio to the elements and it's no longer waterproof, i.e. forget sticking this in the grab-bag as you'll be sorely disappointed - unless you want to throw it at passing ships. I'm also not convinced that constantly removing and inserting the battery doesn't wear out the seals.
I *strongly* recommend that you avoid ANY handheld with a soft off switch, and particularly Icom.