After a few weeks, I've been able to fully test the battery (Max). According to the company's website, the Max battery is supposed to have a 15-20 mile (24-32 km) range. It does NOT perform to these specifications. Don't understand this at all because surely they must have made countless performance tests. I tested it a few times going to work and back (round trip: 7 km). After the second trip (so a total of roughly 15 km or 9.3 mi), the battery started to flounder, going in and out of power. And I did not even have the maximum level of assist at 5; it was at 3 for both trips. The coordination between the battery's indicator and the handlebar's LED display was also not on (the former fluctuating between 2 and 3 lights and the LED display indicating 1). Okay, yes, we can charge the battery more often to avoid all this. But their marketing info should be pretty near the mark, and our experience/tests do not confirm this at all. VERY disappointing (not least given the extra cost of the Max battery).