# Truck battery Varta J3 12V 125Ah 950A ![Truck battery Varta J3 12V 125Ah 950A](https://baterias.com/4227-home_default/battery-varta-j3-12v-125ah-950a.jpg) > Varta J3 truck battery 12V 125Ah 950A. Official Varta Distributor. ProMotive SLI range. Dimensions 286×269×230 mm. For heavy-duty fleets. **Category:** [Truck Batteries](https://baterias.com/gb/batteries-for-truck) → [VARTA](https://baterias.com/gb/varta) - **Canonical URL**: https://baterias.com/gb/battery-varta-j3-12v-125ah-950a - **Language**: en-GB - **Brand**: VARTA - **Reference**: BCOM-VARTA-J3 - **EAN**: 4016987166543 - **MPN**: J3 - **Price**: 327,50 € - **Stock**: Out of stock ## Technical specifications | Feature | Value | |---|---| | Brand | VARTA | | Reference | J3 | | Model | ProMotive SLI (antes ProMotive HD) | | Voltage (V) | 12 V | | Largo | 286 mm | | Ancho | 269 mm | | Alto | 230 mm | | Peso | 36.8 kg | | Tecnología | Lead-acid | | EAN | 4016987166543 | | Terminal layout | 2 | | Terminal type | 1 | | Hold down | B00 | | Cold cranking amps (EN) | 950 A | | Capacity (C20) | 125 Ah (c20) | | ETN | 625023000A742 | ## Quick description **Varta J3 12V 125Ah 950A** is a professional battery for heavy commercial vehicles. Withstands constant chassis vibration, supports long cold-engine cranks and keeps auxiliary services running (tachograph, heater, refrigeration, GPS) during driver's mandatory rest stops. ## 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 🔌 Voltage 12 V ⚡ Capacity 125 Ah C20 🔋 Cold cranking 950 A EN-1 📏 Dimensions 286×269×230 mm ⚙️ Technology Lead-acid ⚖️ Weight 36,8 kg 🏷️ Model ProMotive SLI ## Description ## Varta J3 ProMotive SLI (formerly ProMotive HD) 125Ah 950A 12V Lorry Battery 12*V* Voltage 125*Ah* Capacity 950*A* Cold cranking 36.8*kg* Weight The **Varta J3 lorry battery** is the **12 V**, **125 Ah** model delivering **950 A** of cold cranking power (EN), from Varta's **ProMotive SLI (formerly ProMotive HD)** range, designed for lorries, buses, large vans and machinery. It replaces the original battery in lorries with the 286 × 269 × 230 mm format without any modifications: the same 125 Ah capacity. - High cranking current for large-capacity diesel engines. - Withstands the vibration of thousands of kilometres on the road. - Reinforced grids and casing for the severe demands of haulage. - Dependable through repeated starts and while powering cab equipment. ### Applications of the Varta J3 battery Designed for lorries, buses, large vans and machinery, the Varta J3 is a direct replacement when you need its same 125 Ah capacity and format. Check that it matches your current battery in dimensions, terminals and hold-down: this reference weighs 36.8 kg and has terminal 1 and a B00 hold-down. ### Format and fitting of the Varta J3 In format, the Varta J3 measures 286 × 269 × 230 mm (length × width × height) and weighs 36.8 kg. It takes a B00 hold-down and terminal 1, the system that anchors it to the vehicle's battery tray. Checking the three dimensions and the terminal position before buying avoids the most common mistake when replacing a battery. ### The Varta J3 and the ProMotive SLI range The **ProMotive SLI** range is Varta's starter series for commercial vehicles — lorries, buses and machinery — and in the new portfolio it unifies the former ProMotive HD (Heavy Duty) and SHD (Super Heavy Duty). It offers high cranking current for large-capacity diesel engines and a reinforced construction. Its reinforced grids and separators stand up to the vibration and cycling of long-distance haulage and of the most severe use, aiming for maximum service life and starting reliability in fleets that work long hours. Commercial vehicles demand high cranking current and endurance against the vibration of thousands of kilometres. This series uses reinforced grids and a robust construction to cope with repeated starts of large diesel engines and with the draw of the cab's auxiliary equipment. *This battery used to belong to Varta's **ProMotive HD** or **ProMotive SHD** range; following the brand's commercial renaming (2025), it now forms part of the new **ProMotive SLI** series.* ### Why choose a Varta battery Choosing Varta means sticking with the reference the vehicle manufacturer itself signed off in the first place. Against own-brand batteries, the difference is not the purchase price but how many winters the battery lasts before it leaves you stranded. Behind Varta is Clarios, one of the largest manufacturers of starter batteries in the world and a supplier to the assembly lines of numerous car brands. That German engineering heritage translates into reliable starting year after year. Varta is Europe's leading manufacturer of starter batteries: its production volume and quality controls guarantee consistent reliability batch after batch, something own-brand makes cannot always promise. ### Manufacturer's warranty The Varta J3 battery comes with the **official manufacturer warranty**. An important warning for commercial vehicles: most lorries run **two batteries connected in series** (a 24 V installation). If you replace only one, the new battery ends up working alongside the old one — which has already lost capacity and has higher internal resistance — and that imbalance means one overcharges while the other falls short, shortens the life of the new unit and may be treated by the manufacturer as improper use, **voiding the warranty**. That is why it is always advisable to change **both batteries at the same time**. ### Care and maintenance In professional use, checking the state of charge and the battery hold-down regularly prevents breakdowns on the road. Vibration and the high temperatures of the engine bay are what shortens a battery's life most, so secure mounting is key. Keeping the terminals clean and tight and checking the charging system extends battery life in vehicles that clock up long hours. A well-maintained battery reduces the risk of downtime caused by a battery that will not start the engine. ### Technical sheet Download the official technical sheet for this battery with all the manufacturer data. [Download technical sheet (PDF)](/fichastecnicas/data-sheet-battery-varta-j3-125ah-950a-12v-en.pdf) ## Frequently asked questions ### How do I change this battery step by step? 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 (−) 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 trucks with Start-Stop or BMS, register the battery via OBD so the alternator applies the correct charging profile. ### How long does the Varta J3 battery last? Expected lifespan of the Varta J3 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 measurements of the J3 model? Dimensions (length × width × height) are 286×269×230 mm — also written as 286x269x230 mm — 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. ### Will the Varta J3 battery fit my truck? 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 J3 fits 3 verified vehicle versions in our database. ### What are the equivalents of the J3 model? 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 trucks. See the "Equivalents" section to view recommended options at the same performance level. ## Compatible vehicles This battery fits 3 vehicles. Most searched: - [KIA K2500 Platform/Chassis (SD) (2001)](https://baterias.com/gb/car-batteries/kia/k2500-platformchassis-sd) - [KIA K2700 (SD) (1999)](https://baterias.com/gb/car-batteries/kia/k2700-sd) - [KIA K2900 (2008)](https://baterias.com/gb/car-batteries/kia/k2900) ## Technical team (editorial authorship) The FAQs, guides and comparisons on this site are reviewed by the baterias.com technical team — automotive battery specialists since 2012. → https://baterias.com/gb/technical-team --- *baterias.com — Automotive batteries · 2026-10-22*