I use the Rayovac Renewal rechargeable alkalines, and they seem to have as much or more lasting power than a regular Alklaline battery. And you can charge them up at any time, no need for them to drain down to nothing like the nicads.

I'm suprised that your nimh's are only lasting a week! But, as I've found out with my cell phone, they do last a long time (as in number of total charges). They do however eventually develop a memory like the nicads, it only takes longer.

Greg :-)