The lithium battery has a much higher energy density when compared with older technologies such as lead-acid. This means that the lithium battery is much lighter for the same amount of stored electricity. This means less weight on the bike which has many benefits, including more range for the same capacity, better hill climbing for the same power and a bike that is easier to manoeuvre.
The lithium battery is fitted with a battery management system (BMS) which actively monitors the battery. If any of the cells get too low in voltage, it can cut the power and prevent the cell from becoming over-discharged which can cause irreversible damage. The BMS is also active during the charging of the battery and performs a similar function which prevents the cells from receiving too much charge. The BMS is also able to even out the charge between cells with what is known as “balancing” the batteries. This typically occurs at the end of the charging cycle.