Thumbs up for Vertex. Great quality, you can hit a shark on the head and kill it while talking on the radio. There is a battery case for the Vertex which takes standard AA, that’s my backup for the standard NiMH pack.
I can’t tell if my ICOM draws power from the batteries…
I once measured my A20 and it did not draw any current, at least not measurable with my multimeter. And why shoud it? It has no frequency memory or anything else worth keeping under power while switched off. And if one wants to be 100% sure, the battery pack can simply be unplugged.
I am not aware of any “PDA/tablet/smartphone” product which has a switched-off battery life of more than about a week or two.
Since I bought my iPad two years ago, I never paused to use it for longer than two or three days, so I can’t tell. My Samsung phone, an “Omnia” about five years old, has a built in GPS unit. It runs Windows Mobile so there should be some crude air navigation programs for it (I don’t know, I only use it for road navigation occasionally which works very well). And it has a completely removable battery which should remain sufficiently charged for several months I guess. But again, I have not tried that out myself.
The ILS-capable SP400 looks great and takes 8 x AA which is even more interesting.
I really wouldn’t bother. If they can vector me to some airport with an ILS, they can vector me to one with GCA as well. In an emergency that goes down to zero feet. All I need is a handheld radio capable of continuous reception. Instead of spending money on this SP400 thing I would rather do a practice GCA once or twice per year – much more fun than carrying around a little plastic box.
Peter it is four AA, my bad! I use rechargeable Duracells – it was put away with around 70 % charge a couple of months ago, it is down to about 30% now. I expect normal AA might show a bit better performance.
The 196 locks on very quickly.
I have never seen a rechargeable battery which stays charged more than a few months.
It is possible with lithium technology. In around 1992 I designed a product which used Sanyo 2016-size rechargeable coin cells and their charge retention was same as the primary lithiums i.e. about 20 years (they claimed). But I have never seen them used commercially subsequently.
The ILS-capable SP400 looks great and takes 8 x AA which is even more interesting.
It’s an ugly big monster. I thought about it as well but when I held in my hands the first time, I quickly gave up on the idea.
I have never seen a rechargeable battery which stays charged more than a few months.
Some old Nicads do. Among other things, I collect calcultors, preferrably with luminous displays. Among them is an HP-65 (http://www.hpmuseum.org/hp65.htm) of the mid 1970s that has still it’s original battery pack with which it was delivered. I pull it out of it’s box maybe once per year and in most cases, it will just light up when switched on… But I know, they don’t make them like that any more.
It’s an ugly big monster
Only a tiny bit fatter than my ICOM, and 15mm shorter.
But the later ICOMs are smaller.
I remember the HP65. It was £500 then. But it didn’t have the = key so nobody could work out how to use it, and for sure nobody will these days 
Do you have electricity at home, Peter :-) You know what I do? I charge the ipad mini at home ! ;-))
I can also charge it in the plane, of course.
And I have a Yaesu FTA 230 handheld radio. Very small, fits into the glovebox of the SR22 together with a set of spare batteries, cost € 270.
The ICOM A21 is in the basement now …
Everybody with an IT background knows the perverse polish notation! :) It comes natural to people programming hardware in low level assembly, done that for years.
But some thing that has not mentioned yet and must be the topmost item of every emergency bag is a comparatively cheap piece of kit: A headlamp (or similar torch that can illuminate the instrument panel without needing to be held in one hand all the time). Because if you have your total electrical failure, one of the few reasons why you need handheld radio and GPS receiver, your panel will be unreadable – at least when flying in the dark.
