HRM dual battery drainage

Yeah that is fast!  hmm... weird.  In the past mine has lasted at least a year+ with use of 7~15hrs per week.  

Fix... maybe disconnect module from strap when not using, maybe it is detecting it is being used while off chest?  do you wash the strap well (soak for a long time, changing the water regularly to flush salt)?  Contact support they have always been very helpful for my HR straps.  

I always detach the module from the strap. I regularly wash it, yes. So I have no clue what's wrong.

Hi - did this ever resolve itself? I have the same thing, in that it won't turn itself off

I had it for about 12 months and had to change the batter (no issue with that) but ever since it just drains. I suspect it's because it's 'on' even when it's not attached to the strap. I can see it on available devices from my phone's bluetooth page.

I do not have a Dual myself, but in theory, if is still connected to the phone after use, it may help to put it in a well-sealed metal container after use. If it does not have an active connection and has no input, it should shut itself down.

I contacted the support and my belt was exchanged.

Same issue here but in less than 1 week !! (HRM-Pro)
It appears 1 month ago and I have to change the bettery every 3-4 days. I tried several bettery brand with no change.
I tried to call the support but did not manage to have someone and my emails has not been answered yet.

The issue I have is related to the module, I can't see how a new strap would fix that - were you getting the same issue before?