As most of these vehicles have energy loss do to things like clocks, etc. even a lithium battery will need an intermittent charge up
Except for the clock function are there any other things that draw power with the ignition OFF?
Interestingly I had to boost my Lithium battery after a few weeks. It claimed a charge but not enough to turn the engine over... maybe the wet sumping added too much load? Paralleling my old (and by itself defunct in terms of M3W starting) Banner (technically only 2yrs old, but swapped out last year) got it started.
Possibly I have an "electrical leak" somewhere. Only outstanding electrical issue is that the heated seats havent worked since I put the insides back together again last year... probably I should pull the fuse!
