Also if you are getting erroneously high heat rate it probably because some moisture got into your heart rate sensor. Remove the battery cover from the heart rate sensor and let it sit overnight. Once it dries out apply a layer of electrical tape in cross hatch pattern around the sensor and it will be fine. No need to buy another sensor. I use a Polar H7 Heart Rate Sensor and it works perfectly. No need to upgrade to the H10. Polar already took enough of our money.

Hello niekroset2 ,

I found this link to the exact part number 442830:

https://detail.1688.com/offer/5509086147...

Unfortunately the website is in Chinese. My roommate speaks Chinese so I’ll have him take a look at it.

I believe the one you found (part number 452530) will work fine. .1mm of extra thickness is nothing. The battery currently in my Polar V800 is swollen a lot more than that. Polar USA told me if I need a new battery that I should just buy a new watch as if my money didn’t matter. Other than the battery being swollen the watch is still working great. The USB port is a bit tricky, but I believe the problem with the USB post is due to the swollen battery putting pressure on the rear plate.

My Polar V800 was showing crazy high heart beat rates. I tried replacing battery on my Polar H7 heart rate sensor, but still got high rates. Next I tried leaving the battery cover off over night. In the morning I reinstalled the battery and found the problem solved. The heart rate display was normal. I believe enough moisture got inside the Polar H7 Sensor causing the V800 to display erroneous heart rate. Its a good thing I didn’t buy another Heart Rate Sensor. I think a thin layer of electrical tape applied in a cross-hatch pattern should be enough to seal it off.

I spoke with Polar USA. They will not sell me a battery or give me a part number for the battery. If your watch is under 2 years old, I believe Polar USA will replace the entire watch. I plan on taking my watch apart to get part number and dimensions from battery. I will post my results on here. I have to wait until I get a T5 screw driver.