HRM Strap - grossly erroneous readings.

Former Member over 6 years ago

I have a Fenix5X which I use with a Garmin HRM strap for more accurate HR than the wrist HRM. This HRM and strap was purchased about 18months ago. About a month ago the HRM strap started giving grossly erroneous HR. Somedays it's substantially under reading (-30%) but on most days it substantially overheads (+30%) and sometimes it just 'locks' onto a HR mid-run and doesn't change. I've changed the battery and washed the strap but still no difference. The HRM/strap that this one replaced did the same thing at about the 18month mark of it's life :(

The HRM is a Garmin HRM2-SS with the Premium strap (4 sensors)

0 Dr Phil over 6 years ago

Is this the one with the removable sensor module? If so, I too find about 18-24 months use before I have to replace the strap. I rinse mine after every use and wash at least once a week. At least the straps can be had separately for AU$45. Much better than having to replace the whole thing for mega-bucks.

0 Former Member over 6 years ago

Thanks for your reply Phil. Yes - after replacing 2 straps now that's what I was starting to think - Garmin must design the straps with built in 18~24month redundancy so that they NEED to be replaced every 18~24months :( If this is the case I think 18~24months is too short a lifespan - I really think it should be in the 36month time frame.

0 Dexter101010 over 6 years ago

I've paid a lot of money on a HRM-Tri last year and now it is useless. IN the past I have had a HRM-Run and after 2 years of using, now it does not work at all.HHRM-Tri sometimes work and sometimes does not work, most of the time does not work. The watch does not detect it, also the phone can't see it. And the support from Garmin is no help at all, they are so unprofessional. They answer after a month or so and they don't help you but they offer you some robotic answer. So yeah, Garmin making straps that are working only one year and after that you need to buy another expensive one. Anyway I was not so stupid to buy again Garmin strap and I have buyed a POLAR H10. I am very satisfied with this one because I can change the strap whenever I want. My advice for other users is to stay away of Garmin straps. At least for this new ones that you cannot change the strap. I am very sure that not the receiver is defective but the strap is the damaged one.

0 mcalista over 6 years ago

Over time, salts from sweat can build up in the strap, and this can create an easier electrical pathway for static electricity (eg. from the technical fabrics of some running shirts) than for the genuine electrical signals from the heart.

Regular washing is the best way to prolong the life of the strap. If you haven't been washing the strap regularly and you only wash it when it starts to become a problem, it may take more than one wash to dissolve the buildup of salts. In this case, I would recommend a longer soaking in warm water with a mild detergent, followed by a thorough rinse in clean warm water. Note that if your local water supply is "hard" (ie. contains lots of minerals), this will make dissolving salts from the chest strap more difficult.

Pre-moistening the sensors, and even the skin on your chest at the contact points can help create an easier electrical pathway for the the genuine signals from your heart.

0 Dr Phil over 6 years ago

I'm sure it helps but I rinse mine after every use, thoroughly soak it in warm water before each use, and throw it in the washing machine at least once a week (which is pretty much what the care instructions on the strap and in the user manual suggest). And I'm still lucky to get more than 18 months out if it. I've not had to move to the all-in-one straps yet fortunately so $45 every 18 months or so is not too bad.

Not too sure that we can talk about lifespan in terms of months though as life will depend very much on use and care. I'm averaging somewhere around 700 hrs of strap use per year and am very careful about cleaning as I've noted. I am aware others aren't quite so 'dedicated'. So over 18 months I'm looking at close to 1000 hrs of use. I have no idea whether that's reasonable or not. I think I would look at that a bit more closely if I had to replace an all-in-one strap as often.

0 Former Member over 6 years ago

I've ordered (yet another) replacement strap for the HRM. In the mean time I've got the current one soaking for an extended period to see if that will break up any salts.

0 Former Member over 6 years ago

Okay - I received the new Garmin strap for the Garmin HRM today. Tried it out and it's even much worse! I'm sitting in the car driving with a heart rate of 244bpm! Went for a run and I'm getting very high heart rates all over the place. One minute 235bpm then 190bpm then 153bpm then up to 244bpm. My actual heart rate would be around a constant ~144bpm whilst running. I have washed the HRM unit itself but it's still the same. Am I supposed to re-calibrate the Fenix5x to the new HRM strap or something?

0 Dr Phil over 6 years ago

No. You need only make sure it is paired first. Are you wetting the strap before you put it on? The other one is definitely out of the way?

0 JSRUNNER_ over 6 years ago

NeoSamurai not a calibration issue assuming that the contacts are nicely wetted on the strap then it sounds like the module itself. I see from your post that you have changed the battery. If you search the thread I think there is a way to force the module to do a reset which might help. Failing that sounds like the module itself is faulty.

0 Dr Phil over 6 years ago

Reset the module by putting the battery in reversed for about 30s, then replace the right way.