Specifications
| Brand | FULBAT |
|---|---|
| Part number | FT9B-4 GEL |
| Voltage (V) | 12V |
| Capacity (C20) | 8.40Ah |
| Capacity (C10) | 8Ah (c10) |
| Technology | GEL |
| Length | 150mm |
| Width | 68mm |
| Height | 105mm |
Fulbat FT9B-4 GEL 12V 8,4Ah 120A is a motorcycle starter battery with standard JIS code (the one on your bike's original label). Ready to use, sealed and vibration-resistant. Fits any model that takes the same JIS reference — the code your mechanic recognises at a glance.

The Fulbat FT9B-4 motorcycle battery is rated at 12 V, 8.4 Ah and 120 A of cold cranking current (EN), and is designed for motorcycles, scooters, quads and personal watercraft. Its 150 × 68 × 105 mm and the positive terminal on the left make it the exact replacement for the 8.4 Ah battery fitted as standard to many motorcycles.
The Fulbat FT9B-4 is a common replacement in motorcycles, scooters, quads and personal watercraft. If your bike spends the winter standing, a trickle charger stops it reaching spring flat.
It has external dimensions of 150 × 68 × 105 mm. The positive terminal on the left decides which side the cables end up on: it is the detail that causes most buying mistakes, so check it before ordering. Checking the three dimensions and the terminal position before buying avoids the most common mistake when replacing a battery.
Fulbat has manufactured in France since 1978 and specialises in motorcycles and light vehicles. Its catalogue is short and clear, covers almost the whole fleet and works only with sealed, leak-free batteries. All the Fulbat batteries in our catalogue are genuine product, recently manufactured and covered by the manufacturer's warranty.
Fulbat builds the FT9B-4 to the same standards as the rest of its catalogue; what changes between references is capacity, format and terminal position.
GEL technology fixes the acid in a solid gel. That removes maintenance and leaks and gives very long cycle life, in exchange for slightly slower recharging and lower peak current than an AGM.
GEL batteries need lower charging voltages: always use a charger with a GEL mode so as not to damage the electrolyte. Check the resting voltage before the season (above 12.6 V on a charged battery) and make sure the terminals are clean and tight.
The Fulbat FT9B-4 comes with the manufacturer's official warranty. The warranty does not cover discharge through prolonged inactivity: if the bike stands for months, use a trickle charger.
Orders placed before 6:00 pm with the battery in stock ship the same day. Delivery in mainland Spain and Portugal takes 24-48 working hours; for the Balearic and Canary Islands and the rest of the European Union allow 3 to 5 working days. You have 14 days to return an unused battery; in mainland Spain and Portugal collection is free. We email you the tracking number as soon as the parcel ships.
Data sheet
Specific References
Guide to replace your motorcycle battery in 10-15 minutes. Motorcycle batteries are light (2-5 kg) and usually need an 8 mm wrench.
Park on a flat surface, switch off the engine and remove the key. Make sure all lights and electrical accessories are off. Wait 1-2 minutes before starting.
On motorcycles it is usually under the seat, in the rear cowl or behind a side panel. Check the manual — access varies a lot between models.
Use the 10 mm wrench to loosen the negative cable nut (black, marked −) and remove the cable from the post. Move it aside so it cannot touch any bodywork.
Repeat with the positive cable (red, marked +). Important: never let a terminal touch metal of the car while the other is still connected.
Loosen the hold-down clamp or the straps that secure it. Lift the battery carefully — typical weight 2-5 kg. Check the terminals are not corroded before fitting the new one.
Place the battery in the same orientation as the old one (positive terminal on the same side). Tighten the hold-down clamp firmly.
Connect the positive (+) terminal first, then the negative (−). Tighten the nuts with the wrench until each terminal does not move. Apply anti-spark grease if you have any.
Close the bonnet. Start the engine to confirm everything works. On cars with Start-Stop or a BMS, you may need to register the battery via OBD so the alternator applies the correct charging profile.
In most motorcycles it fits in 15-30 minutes with a 10 mm wrench; if the battery is under the seat or in the boot the time can double. See the step-by-step guide on this page. Quick summary: 1) switch off the engine and remove the key; 2) locate the original battery (engine bay, boot or under seat); 3) disconnect the negative (−) terminal first, then the positive (+); 4) loosen the hold-down clamp and remove the old battery; 5) fit the new one in the same orientation — match the polarity shown on the product sheet; 6) connect the positive (+) first, then the negative (−). On motorcycles with Start-Stop or BMS, register the battery via OBD so the alternator applies the correct charging profile.
Expected lifespan of the Fulbat FT9B-4 GEL is 4 to 7 years in regular use (depends on technology and climate). In cold regions it drops slightly due to cold-start stress; in very hot regions it also drops because of electrolyte evaporation. To extend its life: avoid deep discharges (headlights on with engine off), have the alternator checked yearly, and keep the battery clean and properly secured.
Dimensions (length × width × height) are 150×68×105 mm — also written as 150x68x105 mm — following the European DIN standard. Always measure the space in your motorcycle before buying: even one extra millimetre can prevent the hold-down clamp from closing. The height shown includes the terminals.
Three options to confirm: 1) enter your number plate in the finder (DGT/DVLA/KBA auto-detect your model and engine); 2) check the "Compatible vehicles" tab on this page, where we list every vehicle verified by our technical team; 3) if you cannot find your model, message us on WhatsApp with brand, model, engine and year — we reply during business hours (Mon–Fri 10:00–13:30 and 16:40–18:00 (Spanish time, CET)). The FT9B-4 GEL typically fits a wide range of European vehicles thanks to its standard DIN case format.
Directly interchangeable batteries (same dimensions, same polarity, same Ah and CCA) are the OEM equivalents from leading brands: Bosch, Tudor, Exide and, depending on the model, Banner or Yuasa. Exact equivalence depends on technology — an EFB cannot be replaced with a conventional battery in Start-Stop motorcycles. See the "Equivalents" section to view recommended options at the same performance level.
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