Most eBike trouble in spring starts in the fall. A battery left fully charged or run flat in a cold garage is the usual culprit. This guide collects what the manufacturers and safety agencies actually say about winter storage, cold-weather riding and charging, with a link to each source. Where the makers disagree, we say so rather than pick a number for you.
Your manual wins. Every figure below comes from a named maker or safety agency. If your bike’s manual gives a different range, follow the manual.
Store the battery at a partial charge, not full or empty
Most makers recommend a middle charge level for storage, but the target differs by brand:
| Maker | Storage charge guidance | Source |
|---|---|---|
| Bosch | 30 to 60 percent | Bosch eBike Systems: 12 questions about the eBike battery |
| Trek | 40% to 60% if stored for more than 30 days | Trek: eBike battery myths |
| Specialized | About 60%, and recharge to 60% every three months | Specialized |
| Giant | Around 60% | Giant: electric bike battery winter care |
| Aventon | 75% to 80%, checked monthly so it doesn’t drop under 75% | Aventon: eBike winter storage |
The spread is real: Bosch’s ceiling is 60 percent and Aventon’s floor is 75. That is why the manual matters more than any rule of thumb.
Two points the makers agree on:
- Don’t leave it at 100% for months. Trek says a battery stored at 100% for more than a year can lose approximately 20% of its capacity.
- Don’t store it empty. Aventon says batteries should never be stored with the charge level completely depleted.
If your maker gives a check interval, put it in your calendar. Specialized’s three months and Aventon’s monthly check are the two we found.
Where to keep it
- Take the battery off the bike and bring it indoors. Giant recommends removing the battery and storing it indoors at room temperature.
- Bosch’s storage range is 32°F to 68°F in a dry environment. For a humid space where dew can form, Bosch gives 50°F to 68°F. Source
- Avoid the extremes. Tern, relaying Bosch’s battery guidance, says not to store the battery below 32°F or above 104°F. Source Trek recommends bringing the battery inside when temperatures reach either end of the spectrum. Source
- Keep it away from exits and heat. The FDNY’s lithium-ion battery safety tips say not to charge a device near exits and ways out, and not to charge or store a battery in extreme hot or cold temperatures. FDNY safety tips (PDF)
We did not find a manufacturer page that speaks to unheated garages by name. The temperature ranges above are the closest guidance.
Riding and charging in the cold
Expect less range. Bosch says that when it’s freezing outside, the eBike battery’s capacity may be reduced, and Giant says riders commonly get less range from a charge over the winter, with range returning to normal afterward. Neither gives a percentage, and we haven’t found a manufacturer that does, so don’t plan a winter commute around a specific number from a forum post. For how range is really estimated, see our eBike range guide.
Charge at room temperature.
- Bosch: lithium-ion cells should be charged at room temperature (source), and the ambient temperature while charging should be between 32°F and 104°F (source).
- Trek: if temperatures are below 32°F, quality eBike chargers will not charge. Source
- Giant: the battery should be at room temperature before charging, so bring it in after a cold ride and let it rest. Source
In practice: carry the battery inside after a winter ride, let it come up to room temperature, then plug it in.
Charging safety all year
Winter charging usually happens in a garage, hallway or kitchen, so it’s worth repeating what the safety agencies say.
- Be there. The Consumer Product Safety Commission says to always be present when charging micromobility products, and never to charge them while sleeping or when you are not at home. CPSC Micromobility Information Center
- Use the right charger. CPSC says to use only the charger provided with or recommended by the device’s manufacturer.
- Buy certified equipment. NFPA advises purchasing devices and batteries listed by a nationally recognized testing lab, and says to stop using a device if the battery shows signs of damage such as an unusual odor or a change in color. NFPA eBike safety
- Plug directly into the wall. FDNY says not to use an extension cord and to plug the charger directly into a wall outlet.
Quick winter maintenance for the rest of the bike
These are qualitative tips from manufacturers, with no numbers attached:
- Chain: Bosch says a drop of oil on the chain keeps the bike running smoothly, and Aventon says to lube the chain to protect it. Bosch
- Road salt: wash off mud and salt residue with soap and water (Bosch). Aventon adds that you shouldn’t forget to wash salt off right away if you ride on salted roads. Don’t use a direct jet of water on the battery or drive unit; Tern, quoting Bosch, says the battery must not be submerged or cleaned with a direct jet.
- Brakes: Bosch says well-adjusted, well-maintained brakes are a prerequisite for winter riding, and Aventon recommends allowing a longer stopping distance. Aventon
- Tires: Aventon says to check tires periodically through the year, and especially in winter.
Signs it’s a job for a repair shop
Stop using the battery and get it looked at if you notice any of these:
- Swelling, leaking, excessive heat or unusual smells. Trek’s Electra guidance says to look out for unusual smells, swelling or excessive heat, and to contact your local bike shop if you do. Source Aventon lists bulging and leaking as signs of damage. NFPA and FDNY say to stop use on odor, change in color or shape, leaking or odd noises.
- A drop in range or performance. Trek says this may be a sign the battery needs attention.
- Visible damage before charging. Bosch advises checking the battery for visible damage before you charge.
- Drive-system work. Trek says to take an eBike to a qualified retailer with mechanics who know how to work on eBike drive systems.
If that’s your battery, our eBike battery repair directory lists shops that service them, and the broader eBike repair directory covers motors, brakes and tune-ups. The off-season is also a good time to book a tune-up before the spring rush. To find shops near you, browse by state.
A winter checklist
- Check your manual for the storage charge and temperature range.
- Ride or charge the battery to that level, then take it off the bike.
- Store it indoors, dry, away from exits and heat.
- Set a reminder at the interval your maker gives (monthly for Aventon, every three months for Specialized).
- Wash salt off the bike, lube the chain and check the brakes before storing.
- In spring, let the battery reach room temperature before the first charge.
Sources were last checked on October 23, 2026. Manufacturer guidance changes, and not every page we tried to read was reachable, so treat your own manual as the final word.