Everyone wants their electric bicycle to go further. And it doesn’t matter how far your ebike can go; we always want that extra mile.
Sure, the best way to increase your electric bicycle’s range is to install to a larger battery, but upgrading the battery isn’t the only way to get more range. There are many ways to increase your battery’s range including the simple but important method of keeping your battery cool.
Electric bicycle batteries heat up. It’s a fact of life.
It is natural for lithium batteries found in electric bicycles to heat up as they work. This is normal for any lithium battery. However, it is also the nature of lithium batteries to decrease in efficiency as they heat up – and efficiency is the name of the game when trying to increase your electric bicycle’s range.
As your battery decreases in efficiency, it has to use more of its stored energy to power your ebike the same distance. By using more energy, it heats up even more. This continues the vicious cycle while robbing your lithium battery of its own energy and cutting into your electric bicycle’s range.
So what can be done? The answer: cooling.
The best way to improve the efficiency of your battery and get every last electron out of it is to keep it cool while it is operating. The easiest method to accomplish this is with passive air cooling. Passive air cooling just means having air running over your batter while riding to help cool the battery down.
Many people keep their battery stored in a bag in the center of their bicycle frame or in panniers on either side of the rear wheel. While convenient for holding a battery, the bag is also trapping heat inside the battery. The fabric limits the amount of air that flows through as you drive, allowing the battery to heat up.
Even worse are some of the custom cases people build to house their batteries. Big plastic or wooden boxes are great at securing batteries to the ebike but also serve as giant insulators, eliminating any chance for air flow. If you’ve got your batteries in a sealed box on your electric bicycle, try sticking your hand in there at the end of a long ride. It probably feels like a low-grade oven – the opposite of what you want.
A much better option from a cooling standpoint would be an aluminum hard case battery pack. The air inside the aluminum case still heats up as the battery is operating but the aluminum allows it transfer much of that heat out of the case via convection. Aluminum case batteries also mount directly to the frame or rack of the ebike, meaning they are exposed to the air flowing over them instead of being sequestered in a bag or scooter case.
Shrink wrapped batteries don’t have a native mounting solution and are thus often relegated to those bags and custom cases on the back of an electric bicycle. But even in this case, there are measures that can be taken to improve the air flow and get much needed cooling to the battery. Try drilling some holes in the front and back of your scooter case or custom battery box to allow air to flow through. If you use a bag, try cutting some vent holes in a non structural area of the bag. You’ll notice the difference in air temperature inside the case or bag at the end of your next ride, and your battery will thank you!
If you mount your batteries in panniers on either side of your rear wheel, consider getting metal cage panniers instead of bags. The cages will provide more rigid support and will allow air to flow through uninhibited, cooling your battery and helping it run more efficiently.
Increase your electric bicycle’s range with more air flow
It’s all about keeping the temperature of the battery down and getting more air flowing to it. Since we probably aren’t going to be building custom, turbulent flow oil filled battery enclosures any time soon, passive air cooling is our best bet at keeping our batteries cool and getting the most out of your electric bicycle’s range.