E-bikes are “in” – what about safety?

One in ten bicycles in Germany is an e-bike, according to estimates by the Zweirad-Industrie-Verband (ZIV). This means that more than 7 million bikes with rechargeable add-on drives are on the road in Germany. Nearly 2 million e-bikes were sold in 2020 alone.

Given the high number, it is not surprising that battery fires are reported again and again. It’s an event that certainly doesn’t happen often – we see it in the high numbers of energy storage devices in circulation. And yet it can affect anyone.

An e-bike battery consists of individual cells, the technical term is ‘cup cells’. These are connected and are thus able to store a capacity between 400 Wh (watt hours) and 750 Wh. An e-bike battery with 500 Wh weighs about 3 kg. So it’s quite a chunk that you’re driving around with.

Such a battery cell prefers temperatures in the range of 15 to 20 °C. If it becomes too cold or too warm, chemical processes can take place in the cell. And in the worst case, the cell inflates, bursts and becomes inflamed. Some experts speak of 80°C, others already warn of temperatures beyond 40°C. Such a scenario is promoted by damage experienced by the battery. For example, one thinks of falls. But even tiny impurities in the production process pose a risk.

Brennender und explodierender E-Bike Akku

Thermal Runaway

Anyone who has ever witnessed a battery fire will be impressed by the force. Because if one cell catches fire, it causes the next one to react. The so-called “thermal runaway” sets in, a process that can no longer be stopped. The battery burns down to the last cell and cannot be extinguished even with water.

Burns off? This formulation does not do justice to the event. The cells explode and burning parts fly through the area for meters. Garage or garden shed would not survive this. And these are precisely the fire incidents we keep reading about: An allotment garden in Rheinhessen, a bicycle store in Stuttgart – the list is long and gets longer every day.

Nevertheless, it is exaggerated to be afraid of a battery fire. However, respect and a few precautions are in order.

  • Protect the battery from extreme temperatures.
  • Avoid falls and blows, or at least cushion them.
  • Sort out deformed batteries immediately.

When the battery is fully charged, disconnect it from the power supply.

With our fire prevention products, at least the risk of a battery catching fire causing damage to the surrounding area is minimized. E-bike fire protection with silicone coated fiberglass fabric:

VLITEX E-bike battery bag

The nearly airtight sealable bag made of two layers of silicone-coated fiberglass with a thick intermediate layer of glass wool actually manages to keep a battery fire in the bag. We have had this tested several times by fire departments in fire tests (framework data: battery with 400 Wh charged to 95%). The glass fiber fabric of the bag can withstand temperatures of up to 1,000 °C, heat is retained, smoke development is significantly reduced, and flames cannot spread to surrounding objects.

Wait – what does that mean? The fiberglass can withstand the temperatures, but the bag itself can’t?

Well, let’s put it plainly: If your battery catches fire, the VLITEX e-bike battery bag is designed to prevent your home or garage from burning down. Can it? According to our tests, yes – check out the video. Will the bag still be intact afterwards? Probably not. But in this case, doesn’t it matter if Velcro or seams are still intact? After all, the point is to minimize the likelihood of a major disaster.

The bag is large enough to offer enough space even for large batteries – and we now even offer another 10 cm longer XL version. The design allows to carry out cables and thus charge the battery in the pocket.

Charge, store or transport – from now on only in the e-bike battery bag from VLITEX.

Löschdecke für E-Bikes von VLITEX

VLITEX E-bike fire blanket

If the battery is permanently installed or is to remain on the bike for other reasons, then a fire blanket can provide the necessary safety. It is simply placed over the e-bike and would keep flames and heat under cover in the event of a fire, as well as reduce smoke development. The blanket is made of silicone-coated fiberglass fabric – the material from which the fire department’s professional fire blankets are also made. A reassuring feeling, especially when the e-bike is parked unattended in the garden shed or garage.

E-bike fire protection with VLITEX is an insurance. At best, their effectiveness is never verified. However, it gives security and calms the nerves. And that’s what we all want, right?