Poor battery life

I have same problem with right pedals 

I swapped them left and right doors and not the right one drains in a week but the left one is ok for a good bit longer so I just cycle away as if it is an uno left side power meter. Not ideal but no way I’m sending the pedals to garmin for a month…

Thanks for the info. Yes me as well I'm using as single side when this happen. But disappointed for a so expensive device.

Hello. I came to this thread because I recently (about 2 months ago) got a XC200.
Of course, I'm having the battery drain issue. Mine are lasting about 40h.
Then I realized only one battery is dead, the other one works just fine. 

Then I found out another thing: You can configure the XC200 to communicate (well, I'm using a Edge 830) with either ANT+ or BLE protocols.
In another site they were explaining the differences between both systems. Long story short, ANT+ is more popular and it has some advantages interns of communicating with more devices at once, while BLE with only one. But here is where it gets interesting. 

When connecting as ANT+, one of the sensors (usually the left one) works as a master, meaning it connects to the right arm, collects the information and it sends it to the Console, in this case my 830. Then it makes sense, the left battery draining much faster because is doing most of the work.
And when connecting as BLE, either arm connects separately to the console (the 830).

Then, in another place (not related to power meters but to ANT and BLE protocols) says that BLE gets to "go to sleep" more often.

So I'm thinking maybe those "UP to 120 hours" said by Garmin marketing team are when you connect it as BLE instead of ANT+, which is the default setting?

Is just a theory. I'm changing the protocol to BLE now and I will see how it goes.

Power meters ANt vs BLE site:
https://powermetercity.com/2016/02/14/ant-bluetooth-power-meter/

Hi 8235462!

Please view THIS article on battery change tips to improve the performance of the batteries, if you still experience short battery life after using the rubbing alcohol and mineral oil as described in the link, please contact your regional Garmin Support at support.garmin.com

Same issue for me XC200. Original pair of batteries, lasted “long”, no issues. Second and third pairs (Varta) lasted very short, 20-30 hours. In both cases the left battery was the drained ones, voltmeter gave approx 2V, while right battery still had approx 3V. “Fourth” pair I used the two “right” batteries from #2 and #3. Still working.

Will try the cleaning procedure, I also have new battery doors on the way from a support case

The information in that article is not correct with respect to how Rally does the Bluetooth communication.

Irrespective of whether you use ANT or BLE to communicate between Rally and your head unit, the pedals still use a private ANT channel to communicate to each other. When you set up a BLE link between Rally and your head unit, you still communicate only with the left pedal, and it still aggregates data from both pedals before sending it to the head unit.

Secondarily, the BLE operation is optional, while the ANT+ connection is the default. The pedals permit up to two BLE connections (so you can communicate to a head unit and to Garmin Connect Mobile on your phone simultaneously) but these are set up *in addition* to the ANT+ connection, which remains active even when BLE communication is occurring. Therefore, the ANT+ connection by itself is the lowest power option.

Hope I am.not headed down the path many of you have noted.  I have about 1,000 miles on my pedals. Used them 75% on Zwift connected to my computer with BT and connected to my Edge 1030 with Ant. Rode yesterday on the road with zero issues. Battery levels post ride were “ok” per ride summary in Garmin Connect.

Headed out for a road ride today and they would not wake up to connect. Road without them. Once back home I pulled batteries from both pedals. Both registered about 0.3 Volts. 

I plan to replace the batteries tomorrow following the bulletin referenced above. Fingers crossed.