Question about Garmin Forerunner 305 GPS Receiver

3 Answers

Forerunner 305 battery replacement

Thank you for helping with replacing the battery in my forerunner 305, but I would like to know what adhesive you used to re-assemble the top.

Posted by on

  • 3 more comments 
  • rendog8 Aug 07, 2008

    the battery on my garmin forerunner 305 (bicycle) will not hold a charge for more than 45 minutes, and I suspect it needs replacement. How do I go about doing this?

  • Anonymous Oct 12, 2008

    My forerunner does not even start without USB connection

  • TheRedDevil Nov 12, 2008

    I have used the 305 forerunner for just over a year. It has been fine until recenetly when i charge until i get the 'battery charging complete'. I used for 1.40 on Sunday and onTuesday when i turned it on got 'battery low' after 10 minutes it ran out of power. Is this the battery needing replacing?

  • Anonymous May 18, 2009

    Where did your replacement battery from?

  • Don Pattison
    Don Pattison Aug 14, 2014

    I found a guy in Canada that would replace the battery and return the watch in a about a week. Several of my fellow runners have used his services since then with the same results.



3 Answers

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.


    An expert who has posted more than 50 answers, of which 90% or more were rated as helpful.

  • Expert
  • 84 Answers

Automotive silicon/gasket maker.

Use a tooth pick to put a VERY small amount of silicon around the entire seam. Put the two half's together and wrap tightly with electrical tape. Test the unit immediately to see if it powers on and off. If it does not open it back up and raise the small prongs that make the connection from the bottom half to the top half.
If any silicon squishes out the sides wipe with water and a rag.
Let the unit sit over night. In the morning remove the tape.

Posted on Jun 08, 2009

  • B Highfield Jun 08, 2009

    A local battery specialist should be able to match your battery and be able to give you a replacement, just take the original in to them. The problem is the battery is soldered in a can't just be unplugged and removed. It has to be de-soldiered and re-soldiered. DO NOT solder or de-soldier directly on the battery or it will be ruined, possibly explode.
    If you an not comfortable with this or wondering what I'm talking about, it probably should not be attempted.
    Shame on Garmin for making this such a production to have to replace the battery.

  • B Highfield Jun 09, 2009

    For those of you that need to replace the battery. Here is a link to show you what is inside..... Also notice the battery is soldiered in.


  • Level 1:

    An expert who has achieved level 1.


    An expert who has answered 20 questions.


    An expert that has over 10 points.


    An expert whose answer got voted for 2 times.

  • Contributor
  • 23 Answers

Notes on how to replace the battery here

Use RTV silicon to re-seal the case, as stated by the other posters.

Posted on Feb 11, 2011

  • Level 1:

    An expert who has achieved level 1.

    New Friend:

    An expert that has 1 follower.

  • Contributor
  • 1 Answer

I just used ebay to purchase a battery replacement for about $30.00. I haven't sent the unit in yet but will post how it works when I get it back.

Posted on Jan 01, 2013

  • Don Pattison
    Don Pattison Aug 14, 2014

    I got my watch back and it has been working great since. Several other local runners have used the same guy in Canada with the same good results


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

How to remove battery from garmin 205 ?

they are fixed in you have to take the hole thing to bits

Jul 27, 2014 | Garmin nuvi 205W GPS Receiver

3 Answers

NO life in my Forerunner 305

Try first changing the battery if you have but if not better call Garmin and let them repair or replace it if its still under warranty..

Hope that helps..........

Aug 04, 2008 | Garmin Forerunner 305 GPS Receiver

1 Answer

Forrunner305 battery replacement

Jim Rogers had a similar problem and on his blog, he provides complete instructions on how did it. Apparently, Garmin wants $79 to do this work - but it sounds like he did it for significantly less that that.

Check Jim's blog (by clicking) below:

If it looks too involved for you, check Garmin's "Out of Warranty page, below:

I hope this helps & good luck!

Nov 16, 2011 | Garmin Forerunner 305 GPS Receiver

1 Answer

Forerunner 305 GPS Receiver: Is it possible to change the battery in a Garmin F...

Yes you can. Go to the Garmin Website and simply email them asking for the price of the battery and instructions on how to replace your specific model and serial number as they changed in mid year many times.

May 03, 2010 | GPS

2 Answers

Garmin Forerunner battery replacement

It's not always the battery, I assumed it was and opend mine up to check it out but the battery was OK.
Problem was the unit wouldn't start without pressing mode + reset followed by the power button.

I lifted the internal watch contact strips to put a better connection between the two halves but that made no difference.
I found that I couldn't delete all the history and the watch had recently turned itself off on a run after giving a low battery warning => the history was corrupted and caused the watch grief.

The only way I found to delete the history was to load a v 2.80 (or earlier) version of the watch s/w (current 2.90 doesn't delete history and there is no tool to do it!)
Fortunately I had a copy of v2.80 but the old version is not now on the Garmin site (that I saw).
Moral of the story, don't run your battery low for two reasons, Li-ion batteries lose capacity if you run them below ~30% and also if the watch "low battery" turns off while recording it can corrupt the history and really upset the watch.

At least I now know how to open the watch and have found plenty of possible small mobile phone batteries that will fit (Samsung have a few possibilities). The ABSOLUTE max size of a replacement battery is 36mm H x 43 mm wide x 5.8 mm deep.
If you go 43 mm wide you have to trim a couple of internal plastic ridges in the case.

Good luck and try starting after pressing mode + reset if it won't fire up then try and delete all the history.
Also DON'T run the battery low if you want it to last, Li-ion work opposite to NiCad and NiMH which should be fully discharged before recharge. You try and keep them above 50%.


Sep 20, 2008 | Garmin Forerunner 305 GPS Receiver

1 Answer

Replacing battery on Forerunner 305

Well it is an accumulator instead of a battery so just recharge it.
If the accumulatoris gone I think you have to use the garmin support


Aug 11, 2008 | Garmin Forerunner 305 GPS Receiver

1 Answer

Forerunner 305 battery

it's been two weeks since i bought my IPOD ,but haven't played because of these battery problems.

Jul 27, 2008 | Garmin Forerunner 305 GPS Receiver

1 Answer

Pulse meter died on forerunner 305

You may need to re pair the unit with the heart rate monitor. Settings/ General/ Accessories/ Heat rate monitor. RESTART SCAN. OR follow this link (Hope it works) Go here and click on owners manual. Go to page 46. Adding accessories.

Jun 15, 2008 | Garmin Forerunner 305 GPS Receiver

2 Answers

Garmin Forerunner 305

Make sure the small prong under the battery is bent out a bit, sounds like an intermittened connection problem.

Mar 17, 2008 | Garmin Forerunner 305 GPS Receiver

Not finding what you are looking for?
Garmin Forerunner 305 GPS Receiver Logo

Related Topics:

16,473 people viewed this question

Ask a Question

Usually answered in minutes!

Top Garmin GPS Experts


Level 3 Expert

2130 Answers


Level 3 Expert

78919 Answers


Level 3 Expert

3289 Answers

Are you a Garmin GPS Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides