The lithium technology offers higher power density (kWh per kg)  than lead-acid’s. In practice, this translates into a 4 times lighter battery for the same rated capacity. Another key incentive is the lifetime of the batteries with at least twice more cycles expected compared with lead-acid’s, which is backed up by an hassle-free warranty of 5 years.
The flexibility of charging at any point through the day with no maintenance requirement contribute to the overall hassle-free experience.