Batteries show signs of going the distance

With the recent launch by Zero Motorcycles, the world’s largest electric motorcycle manufacturer, of three brand new batteries to power its range of bikes, there are signs that the electric bike ‘holy grail’ – extended range – is finally coming within reach. Its ZF14.4, ZF7.2 and ZF3.6 batteries give a claimed 10% increase in range, with the most powerful ZF14.4 now giving a claimed 179 miles between charges (with city use).

How batteries store power

When talking battery tech, it’s easiest to think of a battery as an electric bike’s fuel tank. Instead of petrol, this ‘tank’ (battery) contains lithium-ion, which allows it to store electricity. The size of this store is denoted in kilowatts (kW) and the higher the rating, the more electricity it can hold. In the case of Zero, the ZF14.4 holds 14.4kW of charge, the ZF7.2 half as much at 7.2kW and the ZF3.6 half as much again. This pattern of size is due to batteries being constructed of cells, so Zero have broken the battery up into chunks much like when you fit multiple batteries to an electrical device.

Why does it matter?

The power the battery holds determines how far the vehicle can travel, much like the capacity of a petrol fuel tank determines range. An electric motor draws the energy from the battery and the more power and torque asked for, the more electricity is taken and the faster its capacity reduces. And that’s key to the future of electric vehicles, the higher the kWs of charge you can store in a battery, the further you can go between recharges and the more power you can give the vehicle. But the real holy grail is ensuring the battery remains compact while you are adding extra capacity.