I changed the battery in the chest belt. Is there

No, mine works fine.

i use a razor and a hammer.or send to me watchrepairbattery.com

Make sure the battery is placed underneath the small copper clip (positive lead) inside, else the circuit isn't complete. It's pretty easy to clothes the battery casing with it above the lead and not even notice it.

There is a problem with your watch. Send it back to Polar it should still be under warranty.

here is the contact information for sending in.

There are two types of straps for Polar:

1) hard rubber/ solid - These can not have the battery changed.

2) soft strap with connector in middle - these you can change the battery.

If you have the soft strap, it will have a small hard around 3 inch long block that "snaps" onto the strap to connect it. These have a battery compartment. Turn it around and you will see the outline for the battery compartment. These are not always easy to open, and the batteries are a little harder to find. Take it into any watch repair and they should be able to pop a new battery in for you pretty easy.

There is a link on my tips and tricks page to get manuals for Polar products, the T-31 wearlink is the product we are talking about, it has the how to change the battery and battery type.

Read my tips and tricks how to change the battery.

This is really easy to do yourself. Get a CR1632 battery, unscrew the four screws on the back (dont tip the watch as there is a small spring in the watch), unclip the metal band holding in the old battery noting the way 'round the battery is in (minus side up), pop in new battery and push clip back down, when re-fitting the back make sure the spring mentioned earlier lines up with the white sticker with a hole in it on the inside of the watch back, screw down the back. After you have re done all your settings you may need to re-aquaint the watch with the strap, to do this put on the watch and strap, set the heart monitoring going, bring the watch up close to the 'Polar' logo on the chest strap until the time is displayed, should now be all set up.

Andy

unknowingly you know the exact problem.change the battery if does not work .take it to the repair center.thanks.

Nike Triax CV10 - Successful HRM reset 7 November 2008
 
I had real problems too. Even after repeatedly following the known reset steps everyone else is posting up. Here’s how I got mine going, please forgive the mind bogglingly tedious detail…
 
First make sure you’re using new good quality batteries. I used Maxell’s, bought in 10’s from Hong Kong on ebay – no problem.
 
Second, and this is the ESSENTIAL bit…move right away from the computer and any other electromagnetic sources before carrying out the known reset…
 
Third, follow the known reset steps below, adjusted to what worked for me…
 
If you press all four buttons of your Nike HRM it will reset. Next time you go to "RUN" mode, it will show "HRM LINK" error. You will now need to "hard reset" the unit.
 
Nike made a late change to add a "hard reset" to the chest strap. To re-link (re-initialise) the watch you'll need to open the battery door on the chest strap, and use a paper clip (or the equivalent) to push the small gold button in the battery area. There should be a small sticker in the battery compartment that points to the reset button.
 
The re-initialisation steps for the Nike C10 and CV10 digital HRM's is:
 
(1) reset the watch
(2) open the battery door on the chest strap
(3) move the watch to RUN mode
(4) press the reset button in the chest strap battery area without removing the battery
 
Tip - I agree with the suggestion to use a pin or needle and definitely do it with the battery in the hrm.
Tip – Thumb holds battery to stop it from pinging out, other hand performs jiggle with pin until the link is made (it links straightaway if you jiggle it just right!)
 
(5) replace chest strap battery cover…and smile!

If you can't link the hrm do as detailed in the following link If you press all four buttons of your Nike HRM it will reset. Next time you go to "RUN" mode, it will show "HRM LINK" error. You will now need to "hard reset" the unit. Nike made a late change to add a "hard reset" to the chest strap. To re-link (re-initialise) the watch you'll need to open the battery door on the chest strap, and use a paper clip (or the equivalent) to push the small gold button in the battery area. There should be a small sticker in the battery compartment that points to the reset button. The re-initialisation steps for the Nike C10 and CV10 digital HRM's is: (1) reset the watch (2) open the battery door on the chest strap (3) move the watch to RUN mode (4) press the reset button in the chest strap battery area (5) put the battery back in the chest strap (if it's not already in - it's possible to push the button without removing the battery) (6) hold both of the electrode to create a signal (probably not necessary - it usually links immediately). My suggestion is to use a very thin needle and do it with the battery in the hrm. Eventually, Nike will either eliminate the hard reset or update the manual to include this info.