Garmin DC50 gps collar users, a question???

Hey guys,

I conducting some scientific research in Arizona, and I am going to be making some GPS tracking collars for cattle. Commercially available livestock collars are about 1800$/per cow. There is some literature out of Australia that illustrates how to modify an inexpesnive GPS to record tracking data on wildlife. However, those home made devices do not allow you to view the animal in real time, or locate the animal without also attaching a radio frequency VHF antenna.

The Garmin Astro 320 does everything I need, and more. However, the battery life isn't long enough. I was wondering if anyone who owned the DC-50 collar could check the battery to see how much charge it has.

The battery should have its voltage( which I believe is 5V on this collar) and another measurement called Amp Hours or Milliamp Hours ( AH, mAH)?

Thanks

Picture of the replacement battery shows 3.7 volt, 2300 mAh.
http://www.gundogsupply.com/garmin-dc-50-battery-pack.html#

Remember too it has a 9 mile range on level ground on a good day, in case your needing more than that.

Thanks, That is what I needed to know.