Bottom bracket maintenance - is it a thing? Previously when I've had annoying noises from my bottom bracket I've simply discarded it and bought a (cheap) new one.  But the last time I replaced it I got a great offer and splashed out a little bit on a Hope Road Ceramic Bottom Bracket.  A couple of years on (but only 2,000 miles later) I'm getting noises out of it when I pedal.  Due to injury it has sat around for a long time while I recuperated.  I'm trying to avoid replacing the bottom bracket if I can.

I don't need help diagnosing the source of the noise.  Please assume my diagnosis is correct that the noise is from the bottom bracket - ball bearings or any other part of it including it's fitting to the frame

What I'm trying to understand is:


Is there some maintenance (clean and re-grease?) that I should have been doing but missed? Beyond cleaning it externally I've done nothing to the BB
Does the fact that it's ceramic make a difference to question 1?
Are the ball bearings generally a sealed unit or is it possible to open, clean and re-grease them?


My "bike mechanic" skills are self taught since I was a teenager.  Naturally there's things I find I should have been servicing all along or monitoring but simply never knew I had to (for example rim-wear).
To the bearings themselves, not really. It's possible to pull the
seals and clean/re-grease the bearings while they're still
installed, but this isn't something it's expected anyone's going to
actually do. (The one you have I believe has bearing seals that are
pretty easy to get to, making this easier to do if you want it.
Shimano Hollowtech BBs have the bearings covered by a plastic "top
hat" seal that's not intended to be removed and re-installed, and
usually can't be without ruining it.)

For all external cranks, it's pretty common to encounter noises that
can only be remedied by cleaning and greasing the spindle interface.
That might be considered regular maintenance.
No.
In general, all cartridge bearings with rubber seals can have the seals carefully removed, which is something of a skill in and of itself, be cleaned with solvent, rinse, blown dry with air, and re-lubricated. The nature of external BBs is that you won't be able to remove one side's seal, which makes the process more difficult but not impossible. As mentioned above, many external BBs have difficult or impossible to remove parts in the way of the bearing cartridges themselves, and doing anything with the bearing isn't really practical if this is the case.


Another thing that bears mentioning in this conversation is that many Hollowtech 2 compatible external cups can have their cartridge bearings driven out and replaced. Enduro and Phil both make presses just for this. What replacement bearing and seals are appropriate depend on the BB.