Does anyone know if using a PT without the HRM chest strap causes the head unit to eat batteries extra fast? I am wondering if the unit is constantly seaching for or trying to "learn" the HRM that is not there and thus draining the battery. The last two batteries in my head unit have lasted less than a month each time, and I am wondering if this is a possible cause. Is there a way to prevent the unit from doing the HRM search? The unit is an SL 2.4 wireless.

- Yes, the batteries are good when I put them in. Lithium Energizers and I check the voltage prior to using them.

Sounds like a reasonable theory. Have you asked Cyclops support?

AFAIK, the pt headunit only searches for devices for a certain amount of time (for example, when you first turn the head unit, you see the rotating lines on the power and hr displays). If it can't find anything, it just stops searching and displays -- instead of a number.

This is true. You have to initiate 'find' again to get it to see the HR again after a period of time.

Right. I am just wondering this because it obvious that the search phase is a heavy load on the battery ( when the battery is getting low it dims the display in the search phase, like a toaster dimming the kitchen lights ) Was just wondering if others had encountered this.

I think for now I am just going to at least let the unit "learn" the HRM and see if that seems to help, since AFAIK now the units don't actually have to be specifically told to "learn" a new sensor when there is a battery change, they just do it automatically. Am I right on that? Hard to keep up with the new software. So mine is possibly always trying to do the initial learn?

I honestly don't believe that the hr sensor is causing your battery life to decrease. How long do you have to pt set to wait before going to sleep?

Make sure you are using the correct batteries and not the LR44's. They run out much faster.

1 minute, but really since the unit isn't doing anything like searching before it goes idle, an extra minute shouldn't dramatically decrease the battery life.

Am using Energizer ECR2032s

I checked on my ride today to make sure it wasn't searching for the HRM and it shows --- for HR once it finds the hub. I also checked to see if it was doing a HR search after a hub signal loss during the ride, and it doesn't seem to be searching then either.

Can someone explain to me why having the unit in the download cradle would potentially drain the battery, even if the unit has gone to sleep after the DL. I often see this mentioned to explain dead batteries as well.

This is strange. I would try a different source of batteries. You might also try changing the hub batteries.

It doesn't hurt a thing, to not use the HRM. I used mine a lot last year without it. Batteries lasted just fine.

I've never seen the technical explanation, but it's true.

My battery life nearly doubled when I stopped the vicious cycle of download, analyze, update training log, get sucked into hours of FB/BF screen time, fall asleep on couch, go eat dinner, go to bed for real, find head unit still attached to PC in the morning.