Fulbat FTX4L-BS / FTZ5S-BS · Motorcycle battery 12V 4.2Ah 50A AGM

Yes. The FTX4L-BS / FTZ5S-BS from Fulbat uses AGM (Absorbent Glass Mat) technology: a sealed lead-acid battery where the electrolyte is absorbed in a glass-fibre mat. It withstands more charge/discharge cycles than a conventional one, handles heat better and is the required technology for motorcycles with advanced Start-Stop and regenerative braking. Expected lifespan: 5-8 years under normal conditions.

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 our blog. 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 — with positive on the right 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 FTX4L-BS / FTZ5S-BS is 5 to 8 years in mild-climate motorcycle use with Start-Stop. 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 113×70×85 mm — also written as 113x70x85 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.

Polarity: positive on the right. To identify it, place the battery in front of you with the terminals facing you and check which side the positive (+, marked with a red ring) is on. Before buying, verify the polarity matches your current battery: switching polarity forces longer cables or system reconfiguration, with short-circuit risk.

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 FTX4L-BS / FTZ5S-BS 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.