Skip to main content

Battery Care & Safety

Batteries Are the Key

There is no component more important on an e-bike than the battery. It provides the power for your e-bike and is key to how far you can fly or high high you can climb. But regardless of how big and powerful the battery is, the thing we cannot stress enough is how safe a good battery is and, conversely, how dangerous a cheap battery can be. So take a moment to read through this info to make sure that the battery on the bike you want to buy (or perhaps on the bike you already own) is safe and you know how to get the most out of it.

Safety First!

Before we get into proper care & feeding of your battery, the first thing to do is make sure the battery is safe. Battery fires do happen, but the bad press and danger is coming from cheap, poor quality batteries without certification, often purchased online.

Cynergy supports battery certification requirements for e-bikes. Read our letter to the US Consumer Products Safety Commission here.


We have advice on how to tell a good quality battery from one that is high-risk. If you don't have much time, at least read through the following guide on how to identify a safe battery or a potential fire & safety hazard.

Let's begin!

To Avoid Fire & Injury...

follow this advice:

  • Make sure the battery has a UL or CE Certification Sticker:
    Look for a certification sticker on your bike or the battery pack. If you can’t find that sticker, you’re biking on borrowed time. ALWAYS use a certified battery specifically designed for your e-bike.
  • If the bike costs less than $1,000 that is a red flag:
    Prices for e-bikes range from less than $500 to thousands of dollars and average between $2,000 to $3,000. But if your e-bike cost less than $1,000 it probably doesn’t have a UL 2849 or CE certified battery and could be prone to overheat or ignite.
  • What can your retailer tell you about the battery pack:
    Retailers that sell the safest e-bikes have a staff of trained, certified experts who can teach you how to properly maintain your bike’s battery package or do it for you. If you buy your e-bike from someone who can’t tell you everything about it, you’re likely getting a cheap imported battery with a risk of failure.
  • If you crashed your bike you may be at higher risk:
    It’s easy to see damage on a wheel or gears after a collision or fall, but it might not be evident that you damaged your battery. Take your e-bike in for a safety check if you’re concerned at all or you notice an unusual smell or the battery feels unusually hot.
  • If you see fire, smoke or bubbling that is an IMMEDIATE danger!
    All of those circumstances are clear signs your battery is damaged and could ignite at any moment. There’s currently no “check engine light” to give you advance warning, but any of these three circumstances are indicators that you have an IMMEDIATE danger. If possible to do safely, immediately move the bike or battery outside and away from structures & people, then call the fire department immediately. Battery fires are incredibly intense and can be explosive. Act quickly to avoid damage and injury.