Oh, one other thing I wanted to add: The 3-4 year lifetime of lead acid batteries is the average lifetime. There are certainly outliers, but if you go to the st

Oh, one other thing I wanted to add: The 3-4 year lifetime of lead acid batteries is the average lifetime. There are certainly outliers, but if you go to the store and buy a lead acid today, the warranty is about 3 years. The BMW thing is interesting. The reason they do that little "ritual" is because they want to program the ECU to use a particular charging profile for your battery, and it needs to know the age of the battery and the type (AGM or not). That's to try to extend the lifetime of the battery. We don't really need to worry about that, since we handle all the charging profiles internally. One of our testers drives a BMW, so we're making sure that we can handle that and similar cases.