For years I had a Caller ID adjunct box attached before an older landline phone with answering machine that sits on the line for our DSL service. Aside from the small hard-to-read display, the darn thing ate batteries at a ferocious rate. I suppose I could have bought a new phone/answering machine with Caller ID (although many of those displays are hard to read too), but first I thought I would look around to see if I could find a Caller ID box with a large screen that I could plug in to the wall. After a little searching at Amazon I found the oddly named Fans-Tel Type II Large Backlite Screen (actually the Fanstel Model G99M Caller ID Adjunct Box) which fit the bill quite nicely:
The 3 line backlit LCD screen is 3 3/8″ wide by 1 1/2″ tall (viewing area 3.1″ x 1.5″ ) and the large font characters are easy to read since the backlight on the display lights when a call comes in or you are reviewing calls. Better yet it has an AC cord and a brick that I plugged into the same power strip that the phone plugs into. You can optionally insert 3 AA batteries to back-up the memory and run caller ID during power failures. As you might expect, I have not had to replace them in the 6 months I have had the unit.
I do not use the call or message waiting features, but I got just what I wanted: easy to read Caller ID without the battery bill. The price is currently $24.98 at Amazon.