Just an FYI for those looking into getting the CTEK US7002. Since the BMW battery was rated at about 90Ah, I decided to give this CTEK US7002 a try (Amazon had it for $89 back in December). I ran into an issue with this charger in that it kept cycling through the charging modes repeatedly instead of just between float/pulse mode when the battery is fully charged. Found that a few people on the Porsche forum were having the same issue and CTEK had to replaced their units. I ended up returning the US7002 and got the US3300 to replace it. The US3300 is working perfectly so far in the 14.4V mode that I've used. I have not tried the 14.7V mode as that is only recommended for temperature dropping below 41F, which doesn't happen very often in So Cal.