Nick you mention using the AGM setting? I am not aware of the S1 Odyssey model but the S2 onwards just used a normal lead-acid model and not an AGM one as I understood it. So the AGM setting on the charger would not be optimal?
I have used a CTEK 5 on standard setting and maintenance mode pretty much forever. Interestingly the S2 can go ages with a boost but the Coupe cannot go 2 weeks.
I also invested in a Li-Ion battery booster-starter and it has proved very good. It seems odd that something so small and charged using a simple USB-C charger can kick a V8 over!
