# Car battery Varta AUX1 12V 35Ah 520A ![Car battery Varta AUX1 12V 35Ah 520A](https://baterias.com/3961-home_default/battery-varta-aux1-12v-35ah-520a.jpg) > Varta AUX1 auxiliary battery 12V 35Ah 520A. Official Varta Distributor. Dynamic AUX range. Dimensions 212×175×140 mm, + terminal on the right. **Category:** [Auxiliary Batteries](https://baterias.com/gb/auxiliary-batteries) → [VARTA](https://baterias.com/gb/varta) - **Canonical URL**: https://baterias.com/gb/battery-varta-aux1-12v-35ah-520a - **Language**: en-GB - **Brand**: VARTA - **Reference**: BCOM-VARTA-AUX1 - **EAN**: 4016987167816 - **MPN**: AUX1 - **Price**: 147,50 € - **Stock**: In stock ## Technical specifications | Feature | Value | |---|---| | Brand | VARTA | | Reference | AUX1 | | Model | Dynamic AUX (antes Silver Dynamic Aux) | | Voltage (V) | 12 V | | Largo | 212 mm | | Ancho | 175 mm | | Alto | 140 mm | | Peso | 10.75 kg | | Tecnología | Lead-acid | | EAN | 4016987167816 | | Terminal layout | Positive terminal on the right | | Terminal type | 0 | | Hold down | B13 | | Cold cranking amps (EN) | 520 A | | Capacity (C20) | 35 Ah (c20) | | ETN | 535106052I062 | ## Quick description **Varta AUX1 12V 35Ah 520A** is an AGM support battery designed for daily cycling while keeping voltage stable for the vehicle systems. ## Why this auxiliary battery? - **Designed for Start-Stop** built for the intensive cycling of modern cars - **2 to 3 times longer life** vs fitting a cheap conventional battery - **Fast recovery** recharges in minutes once the engine is running 🔌 Voltage 12 V ⚡ Capacity 35 Ah C20 🔋 Cold cranking 520 A EN-1 📏 Dimensions 212×175×140 mm ⚙️ Technology Lead-acid 🧭 Polarity Positive on the right ⚖️ Weight 10,3 kg 🏷️ Model Dynamic AUX ## Description ## Varta AUX1 Dynamic AUX (formerly Silver Dynamic Aux) 35Ah 520A 12V Car Battery 12*V* Voltage 35*Ah* Capacity 520*A* Cold cranking 10,75*kg* Weight The **Varta AUX1 car battery** is the **12 V**, **35 Ah** and **520 A** cold cranking (EN) model from Varta's **Dynamic AUX (formerly Silver Dynamic Aux)** range, designed to work as an auxiliary battery in cars with advanced Start-Stop and a great deal of electronics. It replaces the original battery in cars with the 212 × 175 × 140 mm format without any modifications: the same 35 Ah capacity and the same terminal layout (positive on the right). - Specific replacement for the backup battery fitted to the car at the factory. - Supports the advanced Start-Stop system without voltage drops. - AGM technology: maintenance-free and resistant to cycling. - Auxiliary battery: it powers the vehicle's comfort and safety electronics. ### Vehicles compatible with the Varta AUX1 battery The Varta AUX1 is compatible with more than 9 vehicles: it is fitted as standard or as a replacement by brands such as Mercedes-Benz and Volvo. If you are looking for a **battery for Mercedes-Benz** or Volvo with these dimensions, the AUX1 is one of the usual replacement references. Not sure whether it is the right one for your car? Check in seconds by entering your **registration number** in our finder. ### Format and fitting of the Varta AUX1 Its external dimensions are 212 × 175 × 140 mm and it weighs 10,75 kg. The positive terminal on the right determines which side the cables end up on: it is the detail that causes the most purchasing mistakes, so it is worth checking before ordering. It uses a B13 hold-down, the system that secures it to the vehicle's battery tray. Checking the three dimensions and the terminal positions before buying avoids the most common mistake when replacing a battery. ### The Varta AUX1 and the Dynamic AUX range The **Dynamic AUX** range brings together Varta's auxiliary batteries: these are not the main starter battery but the one that powers secondary functions (advanced Start-Stop, safety and comfort systems) in premium cars. It is installed alongside the main battery and prevents voltage drops in the auxiliary electronics. It is worth establishing clearly whether your car needs this backup battery in addition to the starter one. This series uses lead-acid technology with plates optimised for a good balance between cranking power and service life. It is the natural substitute when your car does not have Start-Stop and came with a standard battery as original equipment: the same philosophy, without paying over the odds for a chemistry you do not need. *This battery used to belong to Varta's **Silver Dynamic Aux** range; following the brand's commercial renaming (2025), it forms part of the new **Dynamic AUX** series.* ### Why choose a Varta battery Varta is a byword for reliability: original equipment in numerous European vehicles and one of the most proven brands on the market. Replacing your battery with a Varta restores OEM quality — the same performance as the factory-fitted unit — with the manufacturer's backing. 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 labels cannot always assure. ### Manufacturer's warranty The Varta AUX1 battery comes with the **official manufacturer warranty**. ### Care and maintenance To get the most out of it, keep the alternator in good order and avoid leaving lights or accessories on with the engine switched off. Repeated very short journeys are its main enemy: they stop the battery from recharging fully and shorten its life. If the car is going to stand unused for weeks, it is worth disconnecting a terminal or using a trickle charger so it does not discharge below the safe threshold. Checking that the terminals are clean and properly tightened also helps ensure reliable starting. ### Technical sheet Download the official technical sheet for this battery with all the manufacturer data. [Download technical sheet (PDF)](/fichastecnicas/data-sheet-battery-varta-aux1-35ah-520a-12v-en.pdf) ## Frequently asked questions ### How is the Varta AUX1 battery installed in the vehicle? In most cars 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 cars with Start-Stop or BMS, register the battery via OBD so the alternator applies the correct charging profile. ### How long does the Varta AUX1 battery last? Expected lifespan of the Varta AUX1 is 4 to 6 years in regular car 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 size is this battery? Dimensions (length × width × height) are 212×175×140 mm — also written as 212x175x140 mm — following the European DIN standard. Always measure the space in your car before buying: even one extra millimetre can prevent the hold-down clamp from closing. The height shown includes the terminals. ### Will the Varta AUX1 battery fit my car? 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 AUX1 fits 9 verified vehicle versions in our database. ### Which batteries are equivalent to the Varta AUX1? 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 cars. See the "Equivalents" section to view recommended options at the same performance level. ## Compatible vehicles This battery fits 9 vehicles. Most searched: - [MERCEDES-BENZ SL (R230) (2001)](https://baterias.com/gb/car-batteries/mercedes-benz/sl-r230) - [MERCEDES-BENZ S-CLASS (W221, V221) (2005)](https://baterias.com/gb/car-batteries/mercedes-benz/s-class-w221-v221) - [MERCEDES-BENZ SL (R129) (1990)](https://baterias.com/gb/car-batteries/mercedes-benz/sl-r129) - [VOLVO B12 (1991)](https://baterias.com/gb/baterias-para-veiculos-de-transporte-publico/volvo/b12) - [VOLVO B9 (2002)](https://baterias.com/gb/baterias-para-veiculos-de-transporte-publico/volvo/b9) - [VOLVO B11 (2011)](https://baterias.com/gb/baterias-para-veiculos-de-transporte-publico/volvo/b11) ## Reviews - **Average rating**: 4.74 / 5 (31 reviews) ## Technical team (editorial authorship) The FAQs, guides and comparisons on this site are reviewed by the baterias.com technical team — over 25 years of experience validating automotive batteries. → https://baterias.com/gb/technical-team --- *baterias.com — Automotive batteries · 2026-10-05*