Polar H10 doesn't automatically disconnect?

yep, same here. my watch can see the h10 even if it is not on the strap. Right now, i have stopped wearing the h10 when i was waiting to get a new strap and i have switched to a 4iiii viva strap. it seems like this one when it is not connected to the strap does not broadcast anymore.

I don't have a Polar H10, but do have a similar  strap. I just disconnect one of the snap connectors when I take the strap off - it turns off after a minute or 2. I leave the other snap connector on, so the monitor stays attached to the strap and I don't lose it.

Yes, same with my old Fenix 6 pro solar (since 10 days I have FR955) and this thing drained battery of H9 in 1 week. I had to remove battery from H9 after each run

I posted a similar question a very long time ago on a polar forum. Although my h10 is disconnected from the strap, if i open my Bluetooth on my phone, i can still see the puck. I was told to be sure that the puck was dry and not still wet. I do not think it affects the battery much though. The viva strap i use right now automatically turn off when not in the strap. My h10 is not used at this time. It is a backup right now.

Does not work with my h10 but does work with the viva strap from 4iiii. But i did not see a huge battery drain though. i replace the battery every 6 months with 5 hours a week of use.

Usually i disconnect one pole, but last week i left it on the table without disconnecting. After a few days (when i didn't touch it, nor was it connected to the watch) the battery of H10 went from OK to low. It's a pitty it wastes battery like this.

I started drying up the contacts after a workout. I think the way to check is open Bluetooth settings on a phone and see if it detects the H10. I guess if the phone sees it, it is still broadcasting and draining battery. I have not checked in a while though and still using it 5 days a week for an hour or so. 

Well I don't know what to say. I am troubleshooting the H10 for something like 3 hours now. At 1st it displayed battery low (the last time I used it 4 days ago it was OK)
So I changed the battery, then I saw there's a firmware update, but my phone couldn't connect to it (because it's android 13), so I tried with a tablet that has android 11, but the same result. At the end when my wife came home I tried with her android 12, and it almost suceeded, this was the 1st device that was able to start the firmware upgrade, but it never finished. Then it started to display that the (new) battery is low!?!?!? so I put back the original battery (that came with the H10 half a year ago), and then finally it managed to upgrade the firmware. Now still with the original battery when I look in fenix6, when it's connected by ANT, then battery: OK, when connected by BT: battery OK, however when looking in garmin connect after I save some workout then with ANT it's OK, but with BT it's low. I guess another bug in Garmin Connect...
So no I still don't really know whether the original battery is OK or low, and whether there's some strange thing going on with the H10 or not. I guess I'll find out in the next few days...

You Have to detache the sensor form the strap, everytime you've finished your train....i found somewhere on the Polar www's...recomandations...in this way you save the battery, after their estimation aprox 1year...