How Long do Bike Lights Take to Charge?

Bike lights are crucial for riding in dark or dull conditions, not only enabling you to see where you’re going, but just as importantly they make you visible to cars, pedestrians, and other cyclists.

Bike lights come in many different shapes and sizes, along with wildly varying price tags. In this article, we’ll look at how long it takes to charge bike lights across all price points.

How Long do Bike Lights Take to Charge?

Most bike lights take anywhere from 1 – 4 hours to charge. The length of time taken to charge depends on the type and size of the battery, temperature when charging, and the power supplying the battery. For USB bike lights, charging via a mains outlet will be quicker than charging through a laptop.

There are many factors that will affect how quickly (or slowly) your bike lights will charge.

Assuming all other factors are equal, a bike light with a larger battery will take longer to charge than one with a smaller battery. This can be a major factor with bike lights since there’s such a wide range of battery sizes used, typically ranging from 1,000 Milliamp Hours (mAh) to 10,000 mAh and beyond.

(The capacitance of a battery is one of the key factors affecting how long a bike light will last on a single charge, as well as its total lifetime. Check out this article to find out how long a bike light will last.)

The vast majority of rechargeable bike lights sold today use lithium-ion batteries, so the main variable affecting the charge time of the battery itself is the size of the battery which influences how much charge it can hold, but there are other variables that have an effect on charge time.

Batteries typically don’t perform as well in colder environments as a result of increased resistance in the charging circuit, plus in the battery itself. Studies have shown that a battery charged at 32 degrees (F) has 36% less charge than the same battery charged for the same time at 77 degrees.

The voltage and current supplying the battery whilst charging is also a key factor to consider when determining charging times. Higher currents and/or voltages will charge a battery more quickly.

Whilst different countries operate on different mains voltages, the more significant effect on charge time is seen when comparing the charge time of a bike light plugged into a mains electrical outlet vs. charging via a laptop.

As the majority of rechargeable batteries today use USB chargers, people sometimes opt to charge them through a laptop for convenience. Whilst there’s nothing wrong with this, it will take longer to charge any device from the USB ports of a laptop when compared to a mains supply.

This is because the voltage and current delivered through a laptop is considerably lower than that of a main outlet.

How Can You Speed Up Bike Light Charging Times?

If you’ve decided to go on a last-minute expedition, just try using some of the points we’ve already discussed to minimize the time it takes to charge your lights.

The most practical way to do this at home is to make sure you plug your light into a mains connection and try to charge your light in a warm room to maximize charging efficiency.