I calibrate the day before and just leave it alone, when I get to my bike during T1 I turn my Garmin on and run out - I have two comments for you;

1. I would recommend you un-link the right pedal and run it in single pedal mode for the race - this will prevent any funky dropouts or anything else and will keep your accuracy consistent the entire race (just until you know for a fact they no longer dropout)
2. I would recommend that you get the replacement battery doors from Garmin - this is supposedly the remedy for a lot of issues that V3 users are having and is free (mine are in the mail)
3. They released firmware 3.50 for the pedals - another one of those things, its supposed to help polish up the hardware.
4. Ride like hell!

I hope that helps and good luck!

Never thought about unlinking the right pedal...great idea, thanks. How is that done exactly??

I am actually on my second set of Vector's. They sent me a brand new pair after my first pair started dropping out (didn't experience any issues until my original batteries went dead). Support promised that the new pair would have an updated battery door (not the ones they are sending now, but better than the first batch). After I had an issue during a sprint a couple weeks ago, I called support and apparently the new pedals they sent have the same door as first pair I returned, go figure. They also told me they couldn't get me the new doors until after the race since they were still in production.

With that being said, I have been riding on the trainer for the last couple weeks without any issues. However, I'm still on the original batteries. It just makes me nervous since riding with power is a huge part of my IM race plan. Hopefully the original batteries will last until after the IM, but unlinking the right pedal sounds like a safe bet.

I leave for Colorado tomorrow morning (vacationing w/ family & friends pre-race) so getting updated battery doors is probably out of the question.

I pair my Vectors to my Edge 1030 and zero them before the race (sometimes need to go for a quick spin outside the transition area to get away from all the other PM's), and then leave everything turned on, with 'autopause' activated. When I get to T1, I grab the bike and go, and the Edge automatically starts when I get above the preset speed. I'm not using the Edge to record an accurate bike split (I also have a Forerunner 935 on my wrist) - the Edge is running a BestBikeSplit power profile, so if it doesn't start for a couple of seconds after I start pedaling it's not the end of the world to me.

I also recently called Garmin CS to order replacement battery doors for my Vector 3's. i told them when my next race was, and they offered to comp me free overnight shipping for the replacement doors. I noticed that the order for the replacement doors includes something called "anti-fretting lube". Apparently one of the issues with the 3's has to do with vibration between the two batteries in each pedal causing wear and a build-up of an oxidized layer of grit between the batteries. As others have noted, you always want to use petroleum jelly or dielectric grease or something on the batteries to prevent this from happening. Even before you get the new battery covers, this may help with a lot of the problems.

I know a lot of people have been bashing Garmin but I think they are genuinely trying to get the issues fixed (they have been great help with me although like you I have not had any real issues).

The unlink is really easy - wake up the pedals and connect to your Garmin connect via phone app and then go into the V3 device - when on the settings page click Device Settings and there should be on that page a button that say's "unlink" that you can click (its for the right pedal). Just click it and it will need to update (generally takes a few minutes) and that's it. You will want to double check that its working after that but it should be smooth and then it will just read the left pedal and the drop outs "should" be eliminated or at least limited to reading the one side.

Cool, thanks for your help

Good luck!

I'd also point out you can set up a training activity on the 520 that doesn't auto shut off. I use it for sprints so I don't know if the battery last through IM, though.