battery change - at what voltage

Once you get down there, the battery voltage will start to drop pretty quickly. The system will shut down with no further warnings at 2.35 volts.

i removed the caps and the sights were interesting. (i must add that my pedals were working perfectly so far)

lots of fretting
https://i.imgur.com/OPpME01.jpg
https://i.imgur.com/GMGOuX4.jpg

right cap has one tape completely missing
https://i.imgur.com/725VJ2T.jpg

so do i:
1) clear black residue on contact points?
2) put some kind of tape on right cap? (or teflon tape around battery?)

had a low battery warning 10 ride hours ago, at 2.59v, then everything was ok until today. another warning at 2.53v. is it time for new batteries? i dread first battery change, so i'm trying to prolong it :)

Zlaja, how do you read battery voltage ?

Thank you

thanks. you use a mac or windows ?

i'm on windows. you can also use https://fit2tcx.runalyze.com/temp, but it's much less readable.

so, the batteries are changed!

1) i cleaned a lot of oily black liqiud residue from contacts on pcb. where did that came from?
2) instead of little black tape, i put a piece of teflon plumbers tape
3) applied baby oil EVERYWHERE
4) retightened caps only by hand

they both lit up and connected to fr935. i'm going for a test ride soon, so fingers crossed :) this was all very stressful, and i don't see my self doing it sweaty and tired by the side of the road :D

https://i.imgur.com/heyWaEv.jpg

did a 18 min ride on my trainer and (knocks on wood) everything works perfectly!

i must say, i really really love this pedals.

i removed the caps and the sights were interesting. (i must add that my pedals were working perfectly so far)

lots of fretting
https://i.imgur.com/OPpME01.jpg
https://i.imgur.com/GMGOuX4.jpg

right cap has one tape completely missing
https://i.imgur.com/725VJ2T.jpg

so do i:
1) clear black residue on contact points?
2) put some kind of tape on right cap? (or teflon tape around battery?)

I have the same issues. I almost got myself killed today on a bike course in the Belgian Ardennes. I never saw the car approaching from the left. This because a message on my Garmin 820 saying that the right powermetersensor is missing and that you have to verify the message. On a descent that's tricky. I just opened the batterycompartment and also noticed this greasy black stuff in the right pedal. Is this the problem?
Maybe I can solve them by myself, but I've spent over $1,000 on a Vector 3. It should work and I shouldn't be messing around trying to solve them. I've contacted Garmin today and hope it will be solved by replacing my V3 for a new pair....thanks for your posts. It helped me anc showed that I'm not alone.

I just opened the batterycompartment and also noticed this greasy black stuff in the right pedal. Is this the problem?

The factory applies an anti-fretting lubricant on the electrical contact points. If it turns out that for some reason fretting occurs anyway, then this can generate the black residue that you see. Your best strategy is to clean up the residue, then again apply a light machine oil or baby oil to the contact points. Check that the insulation tape is still properly in position.

The recommended battery replacement procedure is given in this link.