How to take care of your bike light

A bike light is a small, well-made object. It has a lithium-ion cell, a sealed housing, an LED, a USB-C port, and a strap. Look after those five things and it will look after you for years.

What follows is short, specific, and built around the four numbers worth knowing.

How long should a bike light last?

A rechargeable bike light has two lifespans, and they are not the same.

The LED itself is rated for 50,000–100,000 hours. At one hour a day, 50,000 hours is around 17 years. You will replace the bike before you wear out the LED.

The lithium-ion battery inside it is the part with a clock on it. A well-treated cell gives around 300–500 full charge cycles before noticeable capacity loss — roughly three to five years of daily commuting. Most lights that get replaced are replaced because the battery has aged, not because the light has failed.

The rest of this piece is about how to make those numbers true.

How to charge it well

Lithium-ion batteries do not like extremes. They are happiest sitting between roughly 20% and 80% of a full charge, at room temperature, on a familiar USB-C cable.

A few practical habits:

• Top up often, rather than draining flat. Partial charges are kinder to the cell than running it to zero and then to 100. There is no memory effect to worry about — that was an older battery chemistry.
• Can you leave it plugged in overnight? Yes, on every USB-C light we currently ship. The charging circuit stops drawing current once the cell is full, so the light will not overcharge. That said, sitting at 100% for long stretches is the one habit that ages the cell faster, so unplug when you remember.
• Use a known-good cable. A frayed or counterfeit USB-C cable is the most common reason a bike light suddenly won't charge. If yours has seen a winter or two, swapping in a fresh USB-C cable is the cheapest thing to try before you replace the light.
• Don't charge a freezing-cold light. Bring it inside, let it warm to room temperature, then plug it in. Charging a lithium cell while it is well below freezing is harder on the chemistry — at the cell sizes in a bike light the risk is small, but the habit is worth keeping.
• Watch the indicator. A solid green (or whatever your light shows for "full") means done. Pull it off the charger when you notice — not as a rule, as a habit.

For owners putting serious hours on a Volume 800 or Volume 1500, the Volume Extra Battery is a spare cell pack — keep one charged and you have a fresh pack to slot in when the one on the light runs flat. It also halves the number of cycles each individual pack sees over the year, which is the quietest way to make a battery last longer. And when a pack does eventually age, you swap in a fresh one and the light is effectively new — cheaper than buying a new light, and the rest of the housing keeps going.

How to store it between rides

If you ride daily, storage is not really a question. If your bike sleeps for a few weeks — summer holiday, end of winter season, a flat-bound stretch — the storage question matters.

The principle, from Battery University's lithium-care guide: store a lithium-ion cell at around 40–60% charge, somewhere between 10 and 25°C. A cell parked at 50% in a cupboard loses less than 5% of its capacity per year. A cell parked at 100% in a warm room can lose 20%.

In plain language: do not store the light fully charged, do not store it fully empty, and do not store it on a sunny windowsill or in an unheated shed in February. A drawer in the hallway is exactly right.

Before long storage, give the light a half-charge, click it off, and leave it.

How to keep it clean

Bookman lights are rated for the rain and the salt and the slush of a real Stockholm winter. The IP rating handles weather. It does not handle pressure.

• A damp cloth, then a dry one. That is the whole routine for the housing.
• Never a pressure washer. A close jet finds the seam between housing and lens and pushes water past the seal. No IP rating is meant to defend against that.
• The USB-C port is the part to be gentle with. Salt and grit collect in there over winter. A soft, dry brush — an old toothbrush works — clears it. Do not push anything metal into the port.
• The strap is replaceable. If the rubber on your Curve or Volume strap has hardened or cracked after a couple of winters, a spare strap is a few krona, not a new light.

Cycling UK's lighting regulations page puts it concisely: a light must be clean and working when it is needed. A quick wipe after a wet ride is more useful than a deep clean once a season.

When something is off

A few of the most common signals, and what to try first.

The light won't charge. Try a different USB-C cable, then a different power source (a wall plug, not a laptop port). Check the USB-C port for grit — clean it dry. If a known-good cable and a known-good plug still do nothing, the cell or the port has likely reached the end of its life. Get in touch at support@bookman.se before you replace the light. For the Volume series specifically, a charged Volume Extra Battery is a quick way to test whether the original pack is the problem — and if it is, you can keep using the light on the spare pack rather than replacing the whole light.

It got rained on harder than the IP rating expected. Wipe it down, open any covers, leave it in a dry room overnight at room temperature. Do not put it on a radiator. Do not charge it until it is fully dry.

Runtime has dropped. If a light that used to give you two hours on high now gives you ninety minutes, the cell has aged. This is normal after a few years of daily use. For Volume owners, a fresh Volume Extra Battery is the answer — swap the tired pack for a new one and the light is effectively new. For Curve and Block Light owners, this is usually the point at which the light has earned its retirement.

The button or knob has stopped responding. Spare parts exist — knobs, hatches, screws. The light does not need to be replaced because one small part has worn out.

The four numbers worth remembering

• 3–5 years of useful life from the battery, with normal care.
• 50% is the right charge for long storage.
• 10–25°C is the right temperature for storage and for charging.
• No pressure washers. Ever.

That is the whole guide. Still have questions? Get in touch at support@bookman.se.

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Looking for more? If you are wondering how bright your light really needs to be in the first place, our piece on how bright a bike light should be is the companion to this one.