We use them in our work GPS' and I have found very poor battery life. My Lithium that came with my 530 CHX lasts weeks on end even if I am using daily. Never got below about 60% battery life on a hunt.
If I leave mine on all day, on a 5 watt channel, with limited use, the battery pack only lasts a little more than a day. Both of my hunting partners with the 530 CHX have the same issue. What are we doing different?
I go 20 days or more in the field before I need to charge the rechargeable battery. Mainly because I just turn it on to check either how far I've come or how far I need to go, elevation, or somethign of that nature and turn it right back off. I really don't leave it on ever to track my trails. Just mark the points of interest and turn it right back off. My buddies have the battery packs and like them, but for me its lighter and smaller to just go with the rechargeable battery after using both.
I have the 650 and use rechargables. My best investment was a goal zero solar charger. Charges the 4 AA's in 4-5 hours with good sun, so now I always have a charged set in my rino. Now I'll admit I leave my rino on all day so my batteries just last around 2 days before changing out.
I usually only turn mine on at the top of the hour for 5 minutes and my partners do the same. Generally we have a good idea where people are and if they are hurt or need help they will talk to someone within an hour. I also don't like mine on all day in case they try to call me when I am stalking a an animal or waiting one out and I am in close.
I'm loving this topic. I have a Rino 530hcx that I bought during the winter with the intent of expanding the range of my radio and GPS capability. I have a couple Rino 130's and they have been pretty decent but lacking in the radio department.
I bought an extra rechargeable lithium battery pack from Garmin and one of the packs that allow you to use regular batteries. Two things that suck about the optional battery pack for AA's: it's huge and it reduces your radio power by 50%. I think I'm going to pickup another rechargeable pack for $60 (crazy I know) while I still can.