本頁內容 · 8 sections
The short version
Most “dead” e-bikes have a flat battery, a battery that isn’t clicked fully into place, or a battery that is too cold or too hot to charge (Bosch and Shimano batteries charge only between 0 °C and 40 °C). Try the safe checks below. If the battery is swollen, cracked, leaking, hot or smoking, or has been under water — stop. Don’t charge it. If the checks don’t fix it, book a workshop; don’t open the battery or motor yourself.
Stop first if… (battery safety)
Don’t charge or ride, and move the battery outside away from buildings if it is safe to do so, when the battery:
- is swollen or bulging, leaking, cracked, dented, punctured or crushed;
- is hot, or giving off vapour or smoke;
- has been wet, submerged or in a fire.
If it won’t turn on
- Charge it first. A battery near empty may show no lights at all. Tern’s Bosch guide says no LEDs when you press the battery button means the pack is at or below 5% charge. Shimano says that if the battery’s LED doesn’t light up, the protective circuit is operating — connect the charger to clear it.
- Re-seat the battery. Take it out, check the contacts for dirt, moisture or corrosion, and put it back until it clicks and locks.
- Check the display. Make sure the display sits firmly in its mount and the mount contacts are clean and dry. If the battery has its own power button, try turning the system on from there.
- Look for a loose cable. Cables between the display, battery and motor can work loose (often after transport or a fall). Only push back a plug you can see is out — don’t cut cable ties or open covers.
- Restart the system. Turn it off, take the battery out, wait a few minutes, put it back until it clicks, and turn it on.
If it won’t charge
- Check the temperature. Bosch and Shimano batteries charge between 0 °C and 40 °C; outside that range the charger stops and shows an error (Shimano EC-E6002/EC-E8004 manual; Bosch LEDs 1, 3 and 5 flashing, per Tern’s Bosch guide). Bring a cold battery indoors, or let a hot one cool, then try again.
- Read the charger and battery lights (table below). Use only the charger that came with the bike (or the maker’s replacement). Fire and Rescue NSW: “Just because the plug fits, it doesn’t mean it’s compatible.” The wrong voltage or current can damage the battery.
| Charger or battery | Light | What it means |
|---|---|---|
| Shimano charger (EC-E6002 / EC-E8004) | Lit | Charging |
| Shimano charger (EC-E6002 / EC-E8004) | Flashing | Charge error |
| Shimano charger (EC-E6002 / EC-E8004) | 關閉 | Not connected, or an hour after charging finished |
| Bosch classic batteries (per Tern’s Bosch guide) | LEDs 1, 3 and 5 flashing | Outside the charging temperature range |
| Bosch classic batteries (per Tern’s Bosch guide) | LEDs 2 and 4 flashing | Battery defect — see a dealer |
| Other brands | — | Check the manual; the meaning of charger lights varies |
Shimano: if the battery isn’t full 2 hours after the normal charging time, unplug it and contact the place you bought it. Newer Bosch smart-system (2022+) batteries may use different light patterns — check the Bosch eBike Help Center.
When to book a workshop
Book one when the checks above don’t fix it, when the display shows a code (see e-bike error codes), when a battery shows a defect pattern, or after a crash or water exposure. Bosch and Shimano batteries and motors are serviced through dealers — don’t open the battery or motor yourself (Tern; Shimano tells you to contact the place of purchase).
Find an e-bike workshop near you →
Riding an e-scooter? → 電動滑板車維修
Keep the battery serial, charger model and every repair in a free 單車護照（Bike Passport） — workshops, insurers and the next owner can see the history.
Run a workshop? Get repair requests from riders on EbikeMate →
Storing it so it starts next season
Shimano: if you won’t ride for a long time, store the battery at about 70% charge and charge it every six months, indoors and cool (about 10–20 °C), out of the sun and rain. More in battery health explained.
電動滑板車
The same checks apply to most e-scooters: charge first, use only the maker’s charger, charge at room temperature, and never charge a swollen or wet battery. Scooter codes: e-scooter error codes. Repairs: 電動滑板車維修.
常見問題
Why does my e-bike battery show no lights at all?
It’s usually almost flat, or its protection circuit has switched it off. Connect the original charger; Shimano says charging clears the protective state. If it still shows nothing, see a workshop.
Can I charge an e-bike battery in the cold?
Most Bosch and Shimano batteries only charge between 0 °C and 40 °C. Bring it inside and let it reach room temperature first.
Can I use a different charger if the plug fits?
No. Use the charger that came with the bike or the maker’s replacement — a different charger can damage the battery and cause overheating (Fire and Rescue NSW).
My charger light is flashing — what does it mean?
On Shimano chargers EC-E6002 and EC-E8004, flashing means a charge error. Check the temperature, re-seat the plug and try again; if it keeps flashing, contact the shop you bought it from or a workshop.
資料來源
- User’s manual UM-7K10A-004 (batteries BT-EN404/405/604/605/606/805/806; chargers EC-E6002, EC-E8004) — Shimano (checked 16 October 2026)
- How to troubleshoot the Bosch eBike system on Tern bikes — Tern Bicycles (checked 16 October 2026)
- E-bike and e-scooter battery safety — Fire and Rescue NSW (checked 16 October 2026)
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