# 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**: 146,80 € - **Stock**: Out of stock ## Technical specifications | Feature | Value | |---|---| | Brand | VARTA | | Reference | AUX1 | | Model | Dynamic AUX (antes Silver Dynamic Aux) | | Voltaje | 12 V | | Largo | 212 mm | | Ancho | 175 mm | | Alto | 140 mm | | Peso | 10.75 kg | | Tecnología | PLOMO/ACIDO | | EAN | 4016987167816 | | Scheme | Positive terminal on the right | | Subjection | B13 | | Arranque en frío CCA EN | 520 A | | Capacidad C20 (Ah) | 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 Plomo-Ácido 🧭 Polarity Positivo a la derecha ⚖️ 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 **a 2-year official warranty** from the manufacturer. ### 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 do I check that the Varta AUX1 battery fits my vehicle? Three ways: 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 for the AUX1; 3) if you cannot find your model, message us on WhatsApp with brand, model, engine and year — we reply during business hours (Mon–Fri 9:00–18:00 CET). ### 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 many years of warranty does the AUX1 model cover? This battery includes 2 years of official manufacturer warranty against manufacturing defects. Coverage includes cell breakdowns, internal short-circuits and abnormal capacity decreases. Damage from misuse is excluded: prolonged overcharging, unsuitable chargers or a faulty alternator. Once the defect is verified by technical inspection, we replace the AUX1 at no cost. ### How long does Varta AUX1 delivery take? In mainland Spain and Portugal it arrives in 24 h if you order before 17:00 and the battery is in stock — it leaves the same day and arrives the next business day. Afternoon or weekend orders ship the next business day. For Balearics, Canaries and other EU destinations, allow 2-5 days. Shipping cost is calculated in the cart based on destination and service (standard, express, cash on delivery). Tracking number is sent by email + SMS as soon as the parcel ships. ### Are returns accepted on this battery? Yes. You have 14 days from delivery to return it. In mainland Spain and Portugal returns are FREE — we cover the return shipping cost via prepaid label. In other EU countries the return shipping cost is the customer's. It must arrive in its original packaging with no signs of installation. If it was defective, the warranty covers replacement even after the 14-day period. ### How much does the Varta AUX1 battery cost? The current price at baterias.com is 146,80 € (VAT included; 121,32 € excl. VAT), updated every 24 hours. The applicable VAT may vary with the destination country and is confirmed in the cart. Shipping cost is calculated in the cart based on destination and chosen service (standard, express, cash on delivery). ### Where can I buy the Varta AUX1 battery? At baterias.com — authorised distributor with real stock, 24h delivery in mainland Spain and Portugal if you order before 17:00, and full manufacturer warranty. Shipping cost is calculated in the cart based on destination and chosen service (standard, express, cash on delivery). Secure payment by card, Bizum, PayPal or bank transfer. If you choose at-home installation, our technician will take the used battery and dispose of it through an authorised collection point. ### 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. ### How much does the Varta AUX1 battery weigh? It weighs 10,3 kg. Most of the weight is lead. If you plan to fit it yourself, use gloves and a carrying strap (AGM batteries are slightly heavier than conventional due to the absorbent glass-mat fibre). ### What is the capacity and CCA of the AUX1 model? Nominal capacity 35 Ah[?cca: and [cold-cranking amps 520 A]] at 12 V. Ah measure the total energy available (autonomy); CCA (also written A in cold or EN under the European standard) measure the instantaneous power to crank the starter motor. A battery with more CCA starts better in winter; one with more Ah keeps accessories on for longer. ### 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 9:00–18:00 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. ### Is the AUX1 model better than its equivalents from other brands? This battery and its equivalents from Bosch, Tudor or Exide are technically comparable: same dimensions, same voltage and same capacity. The differences are warranty (Varta and Bosch: 2 years; Tudor and Exide: 2 years on the equivalent line), manufacturing plant (Varta and Bosch share origin in the Clarios Group; Tudor and Exide belong to Exide Technologies) and price. For private use any of these brands will give 4-6 years of life. Compare them in the "Equivalents" section. ### What do users say about the Varta AUX1 battery? The average rating of the Varta AUX1 on baterias.com is 4.76/5 from 26 verified customer reviews. The product rating, when available, is shown on the product page next to the stars. You can also check our public Trustpilot profile at shop level (4.5/5 from 11,202+ verified reviews). Most-praised points: reliable cold start, lifespan above 5 years and fast delivery; most common complaints mention BMS-equipped cars that need OBD registration after fitting. ## 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**: 4.76 / 5 (26 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 · 2026-08-19*