Thursday, August 23, 2012

Forerunner 305 Range Extender

How to extend FR 305s battery life

What do you need?
  • Battery pack e.g. Power Bank 5600mAh (I bought mine at Amazon)
  • Forerunner 305 with the extended (long) strap
  • The charging cradle. NOTE: the charger has a metal plate inside to give it a proper weight (it's meant to stay on the table), remove the three tiny recessed head screws from the bottom of the charger (they are covered by the rubber foam for scratch protection) take out the metal and re-assemble the stuff
  • USB cable
  • some MP3 or phone arm holder

This is how it would look like ...







 

 

 

 

 

Other options?

I just stumbled across this link:
http://www.jimandkatrin.com/CodeBlog/post/Forerunner-305-Battery-Replacement.aspx
This seems pretty cool, so you basically can replace the complete battery and insert some with higher capacity.
Once I have found adequate successor for my Forerunner 305 I might give it a try ;)
Another link describing on how to replace the battery on the 305 (in German):
http://perpetuum-mobile-triathlon.blogspot.com/2011/12/garmin-forerunner-305-akku-wechseln.html.

NOTE: would rather not remove the protection circuit from an Li-Ion battery (if it fits the housing)! This does prevent the battery getting destroyed if voltage drops below 3V or so. If you intend to replace the battery to increase runtime, which means you install a battery that has a better capacity then the installed 720 mAh then it's likely you would run with the watch until it turns off because of an empty battery. In this case you should not remove the little circuit from the battery (Only do this if you're able to recharge before the battery is completely drained)!
Note 2: I think there's no Li-Ion cell with attached charging circuit (looking at the bare cell)? So in any case charging is done by the device, so it holds true that this circuit is not required for proper charging of the battery when put inside the Forerunner.


No comments: