Electric mountain bikes are the best they’ve ever been, with battery capacity increasing to phenomenal levels and some brands offering 1,000Wh batteries with their bikes.
However, ride for long enough and your battery will still die, regardless of size. Just knowing that fact can make a ride stressful. No one wants to pedal a hefty electric mountain bike back to the car without any help from the motor.
That stress can be minimised, though. There are a number of simple and easy-to-implement ways to ensure you're never left without assistance. Apart from the option of buying a range extender or second battery (which can be costly), the tips listed are inexpensive ways to reduce your range anxiety.
Here are the best ways to prevent your ebike running out of battery unexpectedly.
Smart battery management apps
We live in a world of incredible software and eMTBs also benefit from clever developers' inventions.
Most eMTBs have a display that tells you how much battery power is remaining, but this still leaves it up to you to manage your battery life by guessing which assistance modes will enable you to complete the ride.
However, apps such as Specialized’s Mission Control and Bosch’s Range Control feature take it one step further, to all but eliminate range anxiety.
If you input your route into these apps, a complex algorithm will manage the assistance level the bike will give you in order to optimise battery usage. The Mission Control app even takes into account the level of vertical ascending and how much battery you want to remain at the end of your ride.
The feature then updates every few seconds to alter the assistance level your bike is offering you in real time, rationing the power to help ensure you have enough battery capacity left to complete your planned route.
Specialized recommends: "If you want to use the whole battery capacity during your ride, set the capacity at destination to 10%. This safety margin will guarantee that you reach your destination with motor support.”
Perhaps this is the ultimate use of software to combat range anxiety.
Keep your cadence up
“Cadence is one of the most important factors riders can influence to help reduce energy consumption,” explains Chris Astle from Bosch Ebike Systems.
Electric mountain bikes can have phenomenal torque figures, which tempt you to push a high gear and rely on the motor’s torque to keep you moving. “At a low cadence, such as when climbing a hill in a high gear, the motor must provide high torque at a low rotational speed. This requires a very high current, which significantly increases energy lost as heat and thus wastes power from the battery,” says Astle.
Therefore, increasing your cadence is a great way to extend your battery range (and preserve your eMTB's motor).
“When you maintain a cadence of 70 to 90 revolutions per minute (RPM), the electric motor operates in its peak efficiency sweet-spot,” explains Astle. This minimises both strain and current draw. Specialized also says on its website that keeping cadence above 70rpm will ensure you “get the best and most consistent motor support".
Shimano's website concurs, advising: “The EP8 System likes to be ridden at a cadence from 70 to 90 RPM to give the drive unit its most effective output."
Many eMTBs can be programmed to offer a Shift Recommendation prompt, which appears on the display, reminding you to optimise your cadence.
Buy a range extender
Many companies offer range extenders, which are external battery packs that plug in and offer extra capacity. Most deliver between 160Wh and 280Wh of extra electrical power – around a quarter of the capacity of a typical ebike battery.
Some are used up in series (draining the range extender first, before the bike’s battery) and some are used up in parallel (using charge from the range extender and main battery at the same time).
The best range extenders are the ones that offer power in series, because if you’re doing laps of a trail (or plan a route past your car or house), you can drop the flattened range extender off when it’s empty. This sheds some weight, helping your bike handle better, and increasing your range for the rest of the ride.
If you must have the absolute maximum range (and your eMTB has a detachable battery), you could follow in the footsteps of pro trials rider Danny MacAskill. He has been known to go on eMTB rides so epic that he carries a spare battery in his backpack, ready to swap in when he’s used up the first one.
It’s heavy to carry a spare battery, and expensive to buy a spare, but it’s perhaps the ultimate belt-and-braces method of combatting range anxiety, albeit in an extreme way.
Use half your power and then head home
While this is a crude rule, it is one of the simplest ways to combat range anxiety – once your battery level has passed the halfway point on the display, turn and head for home (or your car).
Of course, this won’t work if you’re doing a loop, but if you’re following bridleways off into the countryside, it’s a relatively consistent way to keep track of your range.
A good way to enhance this rule is to drop down an assistance level as you make the U-turn. For example, if you’ve spent your first half of the ride in ‘Trail’, you could switch the bike into ‘Eco’ as you turn around. Even if you toggle the bike back into ‘Trail’ periodically for climbs, you’re more likely to get all the way to your end-point with at least a little reserve range left to spare.
Charge your eMTB just before you ride it
There are two reasons why charging your eMTB just before your ride is a great idea.
The first is obvious – if you charge your battery right before you use it, you will have the maximum charge level, because you will have minimised the amount of battery discharge before you begin using it, keeping it fresh.
The second point is about looking after your battery – eMTBs use lithium-ion batteries, and their lifespan is optimised by storing them with less than 60% charge.
Storing an eMTB battery at 100% charge accelerates chemical degradation, increases internal stress and permanently reduces capacity over time. Therefore, it’s best to store your eMTB with a moderate level of charge, and plan to plug it in and reach full charge right before you want to use it.
Save boost mode for when you really need it
Selecting the highest level of assistance, offering maximum power and torque, is of course, the ultimate way to use eMTB tech, but it’s the one that will zap your battery life more than any other.
If you’re really struggling with a steep climb, or you’re exhausted, this mode is for you, but if not: could you be saving battery, investing a little more yourself and making your battery last longer?
Many modern eMTB systems (including those from Specialized, Bosch, Avinox and Shimano) have modes that are configurable to offer the level of assistance you desire. This enables you to tune the modes to offer different levels of assistance according to whether you’re going for maximum power, maximum economy or using more of your own fitness to power your eMTB.
You can minimise features such as overrun, which use extra battery power and decrease the assistance level offered when economy-focused modes are selected.
