An electric bike’s performance is based on three items – the motor, the controller, and the battery. The battery pack is the single most expensive component of an ebike and as such it impacts the overall experience of owning and riding an ebike. Let’s take a closer look at this most important system.
Essentially, batteries are electrical energy storage containers. You fill them with energy and then you draw from that reservoir as needed over a period of time. They come in various chemistries, capacities, and output capabilities. Modern ebikes primarily use lithium batteries. Beware of any bike that uses sealed lead acid (SLA), nickel cadmium (NiCad), or nickel metal hydride (NiMH) batteries; they’re all old technologies and aren’t worth investing in anymore. Lithium packs last much longer, provide greater performance, and their constituent components are much more recyclable.
A quality lithium battery pack should provide 3-5 or more years of service if cared for properly. The main battery pack is actually made up of a series of smaller individual cells and a small electronic circuit board. The BMS board (battery management system) works with a smart charger to keep the cells properly charged and balanced together. The simplest and best way to maintain your ebike battery is to recharge it after every day of riding. If the bike will sit for an extended period of time (such as winter) its important to plug in the charger and let it run through a charge cycle once a month. This gives the charger a chance to show how smart it is by keeping everything in balance.
Batteries are rated by voltage and by amp/hours. The voltage represents the relative power of the pack (the higher the better). Most ebike systems run at 24, 36, or 48 volts. Here in the mountainous west its best to avoid the 24V systems; you might be disappointed by their performance when it comes to hill climbing capabilities. The amp/hour (AH) rating determines the capacity of the pack and determines the range you can expect from your bike. 10AH is fairly standard. Larger packs (13, 14 15AH) will provide substantially longer run-times but they will add a bit more weight. The mileage range available from ebikes can vary from 15 miles to over 100 miles per charge! Charging only takes 2-4 hours and costs about 5 cents.
When purchasing an ebike make sure you get a solid warranty (1 year or more) on the battery pack – its performance is key to your ebiking enjoyment. So, get out there, burn a few pennies worth of kilowatts, and have some fun!