I am basically GPS newbie and I have a very lightly used Garmin 62stc. I considered adding the paddlenav mapping chip and bringing it with us this year. However, my experience with it just loading waypoints has been the battery life is so bad I would need 3 pockets full of AA batteries to leave tracking on continuously. That's not gonna work and doesn't seem rational either. In checking various websites I have seen 12-15hrs of use is typical and I'm not getting near that loading points with satellite tracking off. Is this correct? Do I need to change some settings to greatly extend battery life or is that really it?

I had a 62st and tracked with it for over 16 hours over 2 days. Much the same as the PN60 I use regularly ( both using Ever Ready LI-Ion). You may need to check your manual for power settings.
You can use BaseCamp and add waypoints/tracks/routes on you computer without using the GPS.
Visit/join the GPS forum for info and help, even files for transfer.

butthead

1. There are lots of 'extra' forums one can join, including the gps forum butthead linked.

2. When working with your gps at home, you can use the cord that came with it to either connect it to a computer's usb port to supply the power (esp. useful if you have mapping applications installed on your computer, i.e. BaseCamp, etc.) or use a converter that lets you plug into a standard 110v outlet (my setup is one that I pieced together with the cords that came with my Rapala corded fillet knife).

3. The best 'standard' batteries I have found to use in the field with my 62st are the Energizer Ultimate Lithium AAs (and, make sure to change your gps' Battery setting to Using Lithium). Yes, I can run a pair of these batteries for two full days of tracking our travel routes and fishing trips before changing them. (And, even then, I am bringing home some only partially used batteries that I can use up fully in places where I don't mind changing them more often.)

I've got a Garmin etrex 20 and I got 20 to 24 hours of tracking per pair of NiMH AA batteries. I had the backlight turned as low as it would go.

I used the NiMH because I have a bunch of them for another purpose. They are the 2000 MAH eneloop batteries.

BnD, I have the same Garmin GPS as you do. Turn the compass off on your GPS as that burns up a lot of battery life. I also use rechargeable batteries in mine. I usually get about 2-3 days use out of mine on a set of AA batteries.

I also use the Energizer Ultimate Lithium because they are made for use with GPS. I have a Garmin Montana with tracking on while I'm paddling, which is usually about 6 hours a day. I turn the GPS off as soon as I get to a campsite. The batteries last for 6 or 7 days.

Energizer Ultimate Lithium

Just need to get some fresh lithium batteries, leave the backlight off, turn off the compass or anything that takes up extra power. My 600 Montana gets about 18 hours on a set. I take an extra set along, lasts a week trip. I also have the battery pack that it came with.