I’m looking to invest in a 4iiii precision power meter - they say it’s not compatible with V650 but I’ve seen a number of threads where users have paired them up since the V650 update.
Has a anyone had any luck pairing the two?
Also, can anyone recommend another crank arm based power meter that’s compatible?
Thanks 
Ey,
bought a 4IIII PRECISION 105 R7000 POWER METER LEFT
and it’s connecting with my v650 (v1.5.5).
Will let you know how it’s working when on the bike.
Cool, let me know how you go!
Ey,
Today I went outside for a test ride and everything worked how it was supposed to be.
For me, it was also unclear if the 4iii was compatible because every review said it wasn’t.
However, for me the 4IIII PRECISION 105 R7000 POWER METER LEFT (4/2020) is working on the Polar v650 (v1.5.5).
I hope it will help you and everybody else that needs this answer.
If you have any questions, feel free to ask.
I’ve just ordered one! The ultegra one, which I’m sure will be the same albeit on a different crank. Fingers crossed!
Forgot to update here… It worked great, albeit there wasn’t enough clearance 
. Faveros it is.
Thx for the review. It helped me a great deal👍
Do they wake-up and reconnect after a let’s say 20 min coffee break?
Also, no power dynamics, right? …just the raw power number (which is absolutely fine).