Problems after battery replace - Rally RS200 - L/R Balance

Update.

Today I put my bike on trainers (Elite Direto XR) with ROUVY to compare data of Power and cadence. I call the Garmin support and they ask me to send the pedals but I want to isolate the problem before.

Power is the correct, max power, avg power… all is ok. Cadence is ok. 

My surprise, balance L/R is ok on the Garmin. 50/50 or 49/51. Same bike, same device, nothing is changed. No strange value and watching cycling dinamic I’ve never lost connection on cycling dinamic menu.

The only things I changed was auto offset turn off. I calibrate pedal manually. Usually I take my bike at home and calibrate my pedals outside immediately. I also calibrate my pedals during the ride when I see strange value of balance but without lucky. 

I’m not sure that the fix was just turn auto offset off. The only things that can change is the sensor connected. 

I have a Varia (I also turn it on and no problems)

A Garmin cardio sensor that I didn’t used today

A Garmin speed sensor that I dint’t used today

A phone paired with Bluetooth but I don’t know if it was connected today because it was in other room.

Why no drop out on the rollers? 

Garmin support where are you?

i dont think that the support will answer to You here, it is a community forum. better to send these info directly to them via email. 

BTW what i have learned my 10+ years long "career" as heavy powermeter-user cyclist that : if You always would like to get perfectly accurate datas without headache you have to buy Power2Max powermeter for your bikes (now I have 3pcs P2M NG /after 4 TypeSs/ on my 3 bikes since 2017, they read within 1watt comparing each other...), that has flawless auto-zero (these pedal based pmeters have different and not so reliable in all circumstances, and there is the angle issue too, too many variables what can ruin the measurement), always spot-on (i have thousands dual/triple recordings with other pmeters ) and zero issue. Ok, it costs more if you have more bikes but you need to buy this only once in your life , and it will run until you die (and the others buy stages, then pedals , with or without luck, there are always something what makes you mad and finally who doing it seriously , sooner or later sold everything and buy P2M and be happy without even any tiny problems ) . this balance and other dynamics things just cheap gimmicks, i had dual Vectors in 2013 already for a few years, there are not too much studies since then what can you do with these extra datas imho or how can you improve yourself by these extra datas or fix the assymetrics, wrong seat or cleat positions... (ok , i know already a few signs from these but if you have good "bike fitter eyes" you can easily notice it by vision )

Thank you for your answer. I know Garmin Power Meter is not "professional" and i am not searching for absolute perfection. 

I send email to garmin support but the only answer was to send the pedal in assistance. 

I prefer to "investigate" because if on the roller they are ok and outside they aren't... maybe in Garmin center they are ok too, but when i received new pedal i still have problem. 

Hi, today I discovered a similar issue, my Rally XC200 right pedal data seems to drop out / go blank on the Cycling Dynamics screen on my Edge 530. It happens sporadically and I sometimes notice the balance swings wildly to the left when it happens. It doesn't seem to happen as often as your example ride tho, so it doesn't show up very much in my FIT file data.

I'm going to try fresh batteries to see if it helps, before contacting Garmin Support. I've had a 60L/40R imbalance issue for over a year that I've been working on (bike fit adjustments, etc), so it's really disturbing to find that maybe the pedals are having issues causing data loss from the right pedal that can skew the balance to the left.

Kyle J Are you in the US or Canada? Let me know if the batteries do not help. 

Hi Garmin-Maeve, I'm in Canada. Still waiting for new batteries to arrive so have not had a chance to test. I suspect it won't make a difference tho because the batteries are not that old and are still showing "3 bars" remaining.

Regarding the intermittent loss of Power Phase data for the right pedal on the Cycling Dynamics display on the Edge, I read elsewhere here on the forum that this sometimes happens when cycling at low power. In my case it seems to occur when the right pedal power is below roughly 50 W, and doesn't seem to occur above that. The lower the power the more likely it is to occur. So if I'm doing very light spinning (warmup etc) around say 100 W total, it's very common to see something like 75 W left / 25 W right, and the right side Power Phase data disappears. Near as I can tell tho, it's only the Power Phase data that disappears, and the actual right pedal power itself is still displayed, it's not lost. So I don't think there is an actual power data dropout for the right pedal (that I can see), instead it's just the Power Phase algorithm can't handle low power values (and tbh that doesn't worry me because it has no practical use at such low power levels anyhow).

That is actually by design. There is a minimum torque level needed to get Cycling Dynamics that is around the 50 watt level.

It makes sense too. The signal conditioning at such low powers would be really challenging to reliably detect the power phase start/end. And in any case the value of that info at such low performance levels would be relatively meaningless.

Anyhow the only reason I picked up on the topic was because I initially thought I was losing right pedal power entirely, because I was seeing the Power Phase data dropout. But since then I see that the right power always stays, and it's only the Power Phase disappearing.  So I don't suspect I'm losing right pedal power signal anymore (at least none that Garmin isn't already covering with that real-time gap-smoothing it does haha).

I had the same problem and it was getting worse. I followed Garmin's guide, but the problem didn't improve.
Pedals out of warranty.

Cleaned with isopropyl alcohol and then ultra abrasive paper tapered spindle copper terminals, battery cover copper terminals and battery cover copper terminals.

NO APPLY GREASE, no it solved the problem, it got worse.

Problem solved, 50/50 indication and power value identical to the Tacx Neo 2 Smart power meter.