I admit I don’t own the R30 but I am in the mindset that no matter what bands you choose to monitor a and b will be the same load on the batteries. It’s not about the band it’s about the time on powered.
While I have never attempted to track battery life on my R30, the two biggest draws on the battery are the speaker and the backlight. If you have both the A-side and the B-side (dual watch) monitoring frequencies that are very active, the speaker will get much more use and depending on how loud it is set at, the draw will be significantly higher. By default, analog frequencies don't cause the backlight to come on (like digital frequencies), however you can set the backlight to come on for analog and thus monitoring airplanes, you will also get a bigger draw on the battery if monitoring on both the A and B sides.
When only one side is active (not in dual watch), the other VFO is not drawing anything and is not accessing the memory, so there maybe a slight saving but difficult to measure.
Thanks DudleyG. Just what I was looking for. Icom has what appears to be a vhf/uhf handheld not released yet. But the fine print has we wondering if they will neuter it. If they don’t, am looking at getting one. Would be nice if that screen was on our R30. Take a look at the ID 52A. If it does cover civ air and mil air, think it would be a sweet radio. Plan on try running civ air and band A and mil air on band B on the R30 to see how it does connected to my discone. Looking at a Omni X mil version too.
According to Icom's website these are the specs for the ID-52A
Receiver (Working Range)
A Band: 108–174, 225–479*
B Band: 137–174, 375-479*
The full civ and mil airband appears to be available only on A band. I don't think the ID-52A is the best radio to monitor air band. The R30 is a much better choice and of course it as a much larger frequency range. The R30 is also pretty fast for scanning. I have the R30 and it is a fine piece of equipment. With that being said, i will probably be interested in getting the ID-52A if it ever becomes available.
I emailed Icom USA to ask about the frequencies. Said until it ships, just go off the web site information. Also mentioned the screen on the 52A would have been nice on the R30. When I saw the asterisk under the frequencies listed, got spooked and not going to pre order. I’ll wait until it arrives before deciding. What you posted about B band already has me rethinking my purchase.