A CF- Wifi or CF-GPS card drains your battery unbelievably quickly. I have a
GlobalSat CF GPS that sits in the back of my closet because it kills my battery too fast. I believe my Axim x51v with a pretty much brand new battery, fully charged, only lasted 1 1/2 hours with that thing. It's a battery hogger.
Your best bet is a Bluetooth GPS receiver (It's a separate device) like
Garmin GPS 10 or
10x (A lot cheaper). Or Google Maps...