In the following guide you’ll learn what battery types and battery specs really mean, practical tips for battery charging (including how long it takes to drain and charge a battery), and how to choose the best type of battery pack when purchasing a new electric bike.
Understanding Battery Specs:
The great thing about battery specs is it’s basically just numbers and math. It may sound intimidating, but with a basic understanding of volts, amp hours, and watt hours (Wh) you’ll be able to quickly assess the true performance benefits (power, speed, and range) of any e-bike.
First off, let’s clear up the term ‘battery pack’. We often refer to the ‘battery’, but with electric bikes, it’s actually a BATTERY PACK. The pack is a number of smaller battery cells assembled in a specific way to deliver the power required to allow an e-bike to function.
Volts - Essentially, VOLT is a measurement of the “force” pushing Amps through the system. Higher voltage means more energy density can be moved, or the faster it can be moved (more volts = more energy being moved through to the motor). 36V batteries are commonly used on entry-level, less expensive e-bikes.
Many electric bikes feature larger 48V batteries at slightly more expensive prices. Juiced Bikes, however, is the only brand in the $1,700-$3,000 segment of the market offering a 52V battery on every e-bike in their portfolio. All else being equal, the larger Voltage system will deliver more torque for quicker starts and more power for higher speeds.
Amp Hours - The amp hour measurement reflects how much energy capacity is in a battery pack. Technically, it’s a measure of how much current the battery can deliver in one hour at a usable voltage. While Volts may impact power and speed, Amp Hours will have a bigger impact on your e-bike’s riding range.
Watt Hours - This is an extremely common spec and refers to the number of watts delivered in one hour. Think of Watt Hours as the total power delivered over time (more power available to you, the rider). To calculate Watt Hours, multiply Volts x Amp Hours. For instance, a 48V 14Ah battery = 672 Watt hours. This is a common spec for many e-bikes in the U.S market.
As a comparison, many of the electric bikes in the Juiced lineup, including the HyperScorpion, RipCurrent S, CrossCurrent X, include a massive 52V 19.2Ah battery, with a total Watt Hours of 998.4 (nearly 50% more watt hour power with the 52V/19.2Ah battery).
It’s critical to know an e-bike’s Watt Hours to understand it’s true riding range potential. Many e-bikes will promote inflated range information, but calculating Watt Hours will help you sort through the dishonest marketing claims.
Reputable, and higher performance, electric bike brands prominently feature these battery specs so that consumers can understand the true power, speed, and riding range capabilities of the bike. Ultimately, higher Volts, Amp Hours, and Watt Hours deliver greater speeds, more power, and longer riding range.
So, if you’re wondering how long it might take to drain an e-bike battery, then pay very close attention to volts, amp hours (and watt hours) to find a bike with the most powerful, longest range battery. Check out our real world riding range calculations for more information on how many miles you can expect to ride based on Watt Hours.
Types of E-Bike Batteries:
This one will probably be a far easier choice for most e-bike buyers as there are really only two primary options for e-bike batteries (and one has far more advantages): lithium and lead acid. We understand there are some other types of e-bike batteries (like the outdated nickel cadmium batteries), but the lionshare of mainstream electric bikes in the U.S. market will include one of these two batteries.
Lithium Ion - This is considered a far superior e-bike battery because of a longer battery life with several thousand charge cycles. They are highly efficient and compatible with fast chargers for 50% faster charge time. About 90% of the e-bike market includes lithium batteries, a clear winner because of their efficiency, durability and ability to generate more power.
Lead Acid: E-bikes with lead acid batteries are not as easy to find and represent a much smaller share of the market. Yes, they are cheap and easy to recycle, but they don’t last long and are sensitive to poor battery management. And, they’re very heavy, weighing 2-3 times as much as a lithium battery. Nearly all experts agree, lead acid batteries are a poor choice for an electric bike.
Before presenting the most important factors to consider when choosing an e-bike battery, here is a quick overview of battery charging and answers to commonly asked questions about charging an electric bike battery.
- All e-bikes should come with a basic battery charger, compatible with that specific battery.
- Charging time varies depending on the size of the battery and the amps of the charger.
- The more amps, the faster the charge… BUT, most e-bike battery chargers max out at 8amps because there are big drawbacks to charging too fast, with too many amps. Charging too fast can damage the battery cells, cause early degradation, and can potentially be a fire hazard. At this time, an 8amp charger is the safest fast charger available. Anything larger is a potential danger.
E-bike Charger Math: divide the amp-hour rating of your battery by the amp rating of your charger, that is how long it will take you to fully charge your battery (if it is fully discharged). So, charging a 19.2Ah battery with a 4amp turbo charger will take around 4.8 hours. With an 8amp fast charger, that same battery will take around 2.5 hours to charge. Here is a great guide for charging time of Juiced Bikes batteries using different chargers: Battery Range & Charge Time.
All good lithium smart chargers, including all of the chargers offered by Juiced, reduce the charge at the end of the charge cycle to ensure a proper balance of power to the battery cells.
- Leaving your e-bike battery charging overnight, or beyond the point of a full charge, is NOT recommended as it can inhibit the charge cycles of a battery.
- Make sure your e-bike is properly maintained with tires inflated at recommended pressure levels.
- During long periods of inactivity, it is recommended to store the battery at 50% charged.
- Find more recommendations for improving the longevity of your e-bike battery with this helpful charging resource guide.
How to Choose the Right E-Bike Battery Pack:
Because the battery pack is such a critical component of an electric bike and will determine the bike’s most important performance characteristics (power, speed and range!), choosing the best battery should be one of the most important considerations in selecting your next e-bike.
Some enthusiasts suggest ranking the following benefits in order of personal importance to find the best e-bike battery: weight, safety, price, power. Unfortunately, at this time, there isn’t a single e-bike battery that delivers everything on the list (inexpensive, safe, lightweight and powerful) and e-bike buyers will need to decide which of these are the most important. For instance, the cheapest e-bike battery will probably be heavy, possibly unsafe, and lack power. A lightweight battery means you’ll need to sacrifice power, speed, and riding range… but if you’re traveling a short distance, only need a small amount of power, and need to carry your bike from a fourth floor walk-up, then sacrificing power might make the most sense. If, on the other hand, you’re looking for an electric bike to reliably take you on a 30-mile commute, and get you there safely, comfortably, and quickly, then battery power is likely far more important than weight.
The best advice we’ve heard is also the simplest: choose the biggest e-bike battery you can afford (unless your situation requires the absolute lightest e-bike possible). Most first time purchasers complain that their most nagging e-bike regret is buying a bike with too little power, range and/or speed. Juiced Bikes is proud to offer an assortment of e-bikes with one of the largest battery packs available in the U.S. market. Because of this superior battery, Juiced is consistently purchased as a rider’s second electric bike… after they discover how important a larger, more powerful battery pack is to their overall riding experience and enjoyment!