Would the awesome battery life matter if it had to be serviced before then, or does this model not need to be serviced until the battery goes dead?/QUOTE]
This link gives a good overview of the movement in an interview with FP Journe :-
https://www.ablogtowatch.com/discussion-f-p-journe-quartz-movement-design/
It includes :-
The secondary reason [for fitting 2 motors] concerns lubrication.
There is no point to extending battery life to up to 16 years if the lubricants all degrade to beyond unusable in less than a third of that time.
The 1210 movement in all F.P. Journe Élégante watches have no lubricated parts at all.
This renders the pieces virtually maintenance free until a battery change is necessary (i.e. even with regular wear for around 8 years).
Most quartz watches use one motor to drive seconds, minutes and hour hands.
The one motor has to drive a 'long' gear-train, so some lubrication is usually provided.
But it is still way better than a mechanical watch because
a) Accuracy does not depend on lubrication
b) In a quartz watch the 'fast' seconds motor drives minutes and hour hands through down-gears
maximum torque is very small.
c) In a mechanical watch the 'slow' spring drives the 'fast' escapement through up-gears
maximum torque and bearing-load is much bigger.
I have 20 year old quartz watches that are working fine without any service other than battery change
I would expect the FP Journe to 'go on for ever'
> Separate seconds and minute+hour motors 'shortens' the gear trains
> No lubricated parts and high-quality construction (18 jewels)
> Motors switch off when the watch is not in use