# Truck battery Fulmen FG1251 12V 125Ah 760A ![Truck battery Fulmen FG1251 12V 125Ah 760A](https://baterias.com/3723-home_default/battery-fulmen-fg1251-12v-125ah-760a.jpg) > Fulmen FG1251 truck battery 12V 125Ah 760A. StartPRO range. Dimensions 349Γ—175Γ—285 mm, + terminal on the left. For heavy-duty fleets. **Category:** [Truck Batteries](https://baterias.com/gb/batteries-for-truck) β†’ [Fulmen](https://baterias.com/gb/fulmen) - **Canonical URL**: https://baterias.com/gb/battery-fulmen-fg1251-12v-125ah-760a - **Language**: en-GB - **Brand**: Fulmen - **Reference**: BCOM-FULMEN-FG1251 - **EAN**: 3661024045414 - **MPN**: FG1251 - **Stock**: Out of stock ## Technical specifications | Feature | Value | |---|---| | Brand | FULMEN | | Reference | FG1251 | | Model | FULMEN StartPRO | | Voltage (V) | 12 V | | Largo | 349 mm | | Ancho | 175 mm | | Alto | 285 mm | | Peso | 29.5 kg | | TecnologΓ­a | Lead-acid | | EAN | 3661024045414 | | Terminal layout | Positive terminal on the left | | Hold down | B00 | | Cold cranking amps (EN) | 760 A | | Capacity (C20) | 125 Ah (c20) | | Case type | D03 | ## Quick description **Fulmen FG1251 12V 125Ah 760A** is an SHD (Super Heavy Duty) truck battery for intensive professional use. Vibration-resistant, withstands long cold-diesel cranks and deep discharges during parking with active loads (tachograph, refrigeration, heater). ## Why this truck battery? - **True Heavy Duty** built for intensive professional use - **Long cold-diesel cranks** reliable even in extreme cold - **Powers services at idle** tachograph, heater and lights with engine off πŸ”Œ Voltage 12 V ⚑ Capacity 125 Ah C20 πŸ”‹ Cold cranking 760 A EN-1 πŸ“ Dimensions 349Γ—175Γ—285 mm βš™οΈ Technology Lead-acid 🧭 Polarity Positive on the left βš–οΈ Weight 29,5 kg 🏷️ Model FULMEN StartPRO ## Description ## Truck battery Fulmen FG1251 StartPRO 125Ah 760A 12V 12*V* Voltage 125*Ah* Capacity 760*A* Cold cranking 29.50*kg* Weight The **Fulmen FG1251** with conventional lead-acid technology delivers **125 Ah** at **12 V** and **760 A** of cold cranking current (EN): what trucks, buses, tractors and heavy machinery demand. Its 349 Γ— 175 Γ— 285 mm and the positive terminal on the left make it the exact replacement for the 125 Ah battery fitted as standard to many trucks. - Better tolerance to deep discharge than a conventional starter battery. - Powers tachograph, fridge and heater during rest stops. - Resistant to constant chassis vibration. - Good balance of capacity, cranking power and price. ### Dimensions, polarity and mounting In terms of format, the Fulmen FG1251 measures 349 Γ— 175 Γ— 285 mm (length Γ— width Γ— height) and weighs 29.50 kg. 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. It uses a B00 hold-down, the system that anchors and connects it in the vehicle. For a direct replacement, the current battery tray must accept these dimensions and the same terminal layout; otherwise adapters will be needed or the hold-down will change. ### What the Fulmen FG1251 is for With 125 Ah, the Fulmen FG1251 cranks large-displacement diesel engines in the cold and powers tachograph, fridge and heater during rest stops. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a weight of 29.50 kg and B00 hold-down. ### The Fulmen FG1251: StartPRO range and conventional lead-acid technology Within the Fulmen catalogue, the **StartPRO** series groups the references designed for this use. The FG1251 is the 125 Ah model of that family, with the same performance as its siblings in other sizes. Conventional lead-acid is the benchmark against which other technologies are compared: good cranking current, great tolerance to alternator charging and the best price per amp-hour. ### Why choose Fulmen batteries With more than a century of history, Fulmen offers complete ranges for cars, trucks, motorcycles and leisure with the industrial quality of the Exide group. At baterias.com we work directly with the manufacturer or its official distributor: real stock, brand-new product and official warranty. ### Manufacturer's warranty The Fulmen FG1251 comes with the **manufacturer's official warranty** against manufacturing defects. An important note for commercial vehicles: most trucks use **two batteries connected in series** (24 V installation). If you replace only one, the new battery works alongside the old one, which has already lost capacity; that imbalance shortens its life and the manufacturer may treat it as misuse. Always replace **both at the same time**. ### Usage and maintenance tips Keep the terminals clean and tight and the battery firmly secured against chassis vibration. On batteries with filler caps, check the electrolyte level and top up only with distilled water. ### Shipping, delivery and returns Orders placed **before [[ks:cutoff]]** with the battery in stock ship the same day. Delivery in mainland Spain and Portugal takes 24-48 working hours; for the Balearic Islands and the rest of the European Union allow 3 to 5 working days. You have **[[ks:return_days]] 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. ## Frequently asked questions ### How is the Fulmen FG1251 battery installed in the vehicle? In most trucks 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 (βˆ’) 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 β€” with positive on the left match the polarity shown on the product sheet; 6) connect the positive (+) first, then the negative (βˆ’). On trucks with Start-Stop or BMS, register the battery via OBD so the alternator applies the correct charging profile. ### How long does the Fulmen FG1251 battery last? Expected lifespan of the Fulmen FG1251 is 4 to 6 years in regular truck use without 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. ### What are the dimensions of the Fulmen FG1251 battery? Dimensions (length Γ— width Γ— height) are 349Γ—175Γ—285 mm β€” also written as 349x175x285 mm β€” following the European DIN standard. Always measure the space in your truck before buying: even one extra millimetre can prevent the hold-down clamp from closing. The height shown includes the terminals. ### On which side is the positive of the FG1251 model? Polarity: positive on the left. 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. ### Is the FG1251 valid for my vehicle? 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 β€” we reply during business hours (Mon–Fri 10:00–13:30 and 16:40–18:00 (Spanish time, CET)). The FG1251 typically fits a wide range of European vehicles thanks to its standard DIN case format. ### Which batteries are equivalent to the Fulmen FG1251? 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 β€” an EFB cannot be replaced with a conventional battery in Start-Stop trucks. See the "Equivalents" section to view recommended options at the same performance level. ## Equivalent batteries - [VARTA J2](https://baterias.com/gb/battery-varta-j2-12v-125ah-720a) - [EXIDE EF1251](https://baterias.com/gb/battery-exide-ef1251-12v-125ah-850a) - [EXIDE EG1251](https://baterias.com/gb/battery-exide-eg1251-12v-125ah-760a) - [TUDOR TF1251](https://baterias.com/gb/battery-tudor-tf1251-12v-125ah-850a) - [TUDOR TG1251](https://baterias.com/gb/battery-tudor-tg1251-12v-125ah-760a) ## Technical team (editorial authorship) The FAQs, guides and comparisons on this site are reviewed by the baterias.com technical team β€” automotive battery specialists since 2012. β†’ https://baterias.com/gb/technical-team --- *baterias.com β€” Automotive batteries Β· 2026-10-20*