Suunto smart heart rate strap freezing after ~30 minutes (Tried battery replacements & cleaning)

[Apor Szabó]

Hi everyone,

I’m reaching out to see if anyone has experienced a similar issue or has any advice.

I’ve had my Suunto heart rate strap for about 3 months now, and it has been working great until this past week, when it started acting really strangely.

The issue:
Every time I go out for a session, everything works perfectly for the first 30 minutes. After that, the heart rate data suddenly freezes/gets stuck on a single value and doesn’t change at all for the rest of the workout, no matter my effort level.

What I’ve tried so far:

Replaced the battery 3 times already to rule out a dying power source.

Next on my list is to thoroughly clean the snap connectors and contacts using a soft toothbrush.

Has anyone run into this exact “freezes after 30 minutes” behavior? Could it be a hardware failure, an electrode/strap degradation issue, or something else entirely?

I’ve attached some photos of the strap itself and screenshots of the data flatlining/freezing during a workout below.

Any tips or troubleshooting steps would be greatly appreciated!

Thanks,!

[elbee]

@Apor-Szabó

Could be the quite common problem where the watch looses connection with a bluetooth device and fails te reconnect.

There is no solution for that problem. Suunto should solve it but I don’t have the impression they are very active looking into it.

[Apor Szabó]

@elbee Thanks for the insight! That definitely sounds plausible. I’m still going to keep tinkering with it and hoping it cooperates properly at some point, but it’s good to know I’m not the only one running into quirks with it.

[Maximfreediver]

@Apor-Szabó
Exactly the same problem, they change it for new one and i’ve got same problem with new. Now i don’t know what to do, because two belts, even new one has the same problem. My watch is Suunto Ocean. Did you find any solutions?

[elbee]

@Maximfreediver

There is no solution. There is a major bug in Suunto’s bluetooth firmware. Suunto either cannot fix it or aren’t looking. (And in my case, I think it is highly unlikely if suunto has a fix it will ever be available for my race s)

I do notice that regularly reboots (like weekly or more frequent) help to mitigate the problem.