# Auxiliary battery Varta A10 12V 40Ah 420A AGM ![Auxiliary battery Varta A10 12V 40Ah 420A AGM](https://baterias.com/4477-home_default/battery-varta-a10-12v-40ah-420a.jpg) > Varta A10 auxiliary battery 12V 40Ah 420A AGM. Official Varta Distributor. Dynamic AGM range. Dimensions 175×175×190 mm, + terminal on the right. **Category:** [Car Batteries](https://baterias.com/gb/car-batteries) → [VARTA](https://baterias.com/gb/varta) - **Canonical URL**: https://baterias.com/gb/battery-varta-a10-12v-40ah-420a - **Language**: en-GB - **Brand**: VARTA - **Reference**: BCOM-VARTA-A10 - **EAN**: 4016987168752 - **MPN**: A10 - **Price**: 105,60 € - **Stock**: In stock ## Technical specifications | Feature | Value | |---|---| | Brand | VARTA | | Reference | A10 | | Model | Dynamic AGM (antes Silver Dynamic AGM) | | Voltage (V) | 12 V | | Largo | 175 mm | | Ancho | 175 mm | | Alto | 190 mm | | Tecnología | AGM | | EAN | 4016987168752 | | Terminal layout | Positive terminal on the right | | Hold down | B13 | | Cold cranking amps (EN) | 420 A | | Capacity (C20) | 40 Ah (c20) | | Additional ETN | 540901042K262 | ## Quick description **Varta A10 12V 40Ah 420A** is an auxiliary battery: it supports the Start-Stop system and on-board electronics during stops, without draining the main battery. ## 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 40 Ah C20 🔋 Cold cranking 420 A EN-1 📏 Dimensions 175×175×190 mm ⚙️ Technology AGM 🧭 Polarity Positive on the right ⚖️ Weight 12,19 kg 🏷️ Model Dynamic AGM ## Description ## Varta A10 Dynamic AGM (formerly Silver Dynamic AGM) 40Ah 420A 12V Car Battery 12*V* Voltage 40*Ah* Capacity 420*A* Cold cranking The **Varta A10 car battery** is the **12 V**, **40 Ah** model delivering **420 A** of cold cranking power (EN), from Varta's **Dynamic AGM (formerly Silver Dynamic AGM)** from Varta, designed for cars with a Start-Stop system and high electrical demand. Its 175 × 175 × 190 mm dimensions and positive terminal on the right make it the exact replacement for the 40 Ah battery fitted as standard on many cars. - Built for the intensive cycling of the Start-Stop system. - Keeps the vehicle's electronic management correctly calibrated. - Reinforced resistance to the partial charges and discharges of daily driving. - A greater guaranteed number of starts than a conventional battery. ### Applications of the Varta A10 battery The Varta A10 covers the needs of cars with a Start-Stop system and high electrical demand with 40 Ah of capacity and a construction built for that use. Check that it matches your current battery in dimensions, terminals and hold-down: this reference has a B13 hold-down. ### Format and fitting of the Varta A10 The Varta A10 is built in the 175 × 175 × 190 mm format. The positive terminal on the right determines which side the cables run to: it is the detail that causes the most buying 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. For the swap to be direct, the space your current battery occupies must respect those three dimensions and the same terminal layout; otherwise adapters will be needed or the hold-down will have to change. ### The Varta A10 and the Dynamic AGM range The **Dynamic AGM** range (gold label) is Varta's top of the range for cars: AGM technology, with the electrolyte absorbed in glass fibre, designed for the most advanced Start-Stop systems and for braking energy recovery. It withstands thousands of charge and discharge cycles without losing performance and is the only correct choice when the car came with AGM from new. Ideal for vehicles with high electrical consumption and very frequent starts. The difference from a conventional battery lies in the construction: separators and plates built for thousands of partial charge and discharge cycles. Fitting a standard battery to a car with Start-Stop shortens its life dramatically; this range avoids that mistake and keeps the fuel-saving system working. *This battery used to belong to Varta's **Silver Dynamic AGM** range; following the brand's change of commercial naming (2025), it now forms part of the new **Dynamic AGM** series.* ### Why choose a Varta battery Manufactured by Clarios to German standards, Varta is one of the world's benchmark brands in starter batteries and an OEM supplier to the leading car makers. Choosing it as a replacement guarantees specifications equal to or better than the originals. Varta combines more than a century of experience with the industrial production of Clarios: it is the battery many manufacturers fit as standard and one of the most recommended by workshops. Like every lead-acid battery, it is 100% recyclable. Varta's production combines automated lines with verification of more than 100 parameters per unit; that traceability is what underpins its reputation for reliable starting throughout the battery's life. ### Manufacturer's warranty The Varta A10 battery comes with the **official manufacturer warranty**. ### Care and maintenance In a vehicle with Start-Stop the battery works much harder, so make journeys long enough for it to recharge and always replace it with the same type (AGM for AGM, EFB for EFB) so the electronic management is not thrown out of calibration. To get the best from it, avoid very short trips, which prevent it from recharging after each start. Keeping the terminals clean and the battery securely mounted prevents faults caused by vibration in the engine bay. ### Technical sheet Download the official technical sheet for this battery with all the manufacturer data. [Download technical sheet (PDF)](/fichastecnicas/ficha-tecnica-bateria-varta-a10-40ah-420a-12v-en.pdf) ## Frequently asked questions ### Is the Varta A10 an AGM battery and what are the benefits of AGM? Yes. The A10 from Varta 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 cars with advanced Start-Stop and regenerative braking. Expected lifespan: 5-8 years under normal conditions. ### Is the A10 model suitable for Start-Stop cars? Yes. As AGM technology it is designed for Start-Stop vehicles. AGM batteries support advanced Start-Stop and regenerative braking thanks to their higher cycle count. EFB is recommended for basic Start-Stop; AGM is recommended when regenerative braking is also present, thanks to its higher cycle capability. It works straight out of the box — on most modern vehicles registering the battery via OBD is recommended so the alternator automatically applies the optimal charging profile. ### How do I fit the A10 model in my car? 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 A10 battery last? Expected lifespan of the Varta A10 is 5 to 8 years in mild-climate car 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. ### What are the dimensions of the Varta A10 battery? Dimensions (length × width × height) are 175×175×190 mm — also written as 175x175x190 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. ### Is the A10 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 — we reply during business hours (Mon–Fri 10:00–13:30 and 16:40–18:00 (Spanish time, CET)). The A10 fits 3 verified vehicle versions in our database. ### Which interchangeable batteries are there for this one? 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. ### Why choose AGM instead of EFB for my Start-Stop car? AGM (Absorbent Glass Mat) technology uses absorbent fibreglass that retains the electrolyte, eliminating leaks and allowing up to 3× more charge/discharge cycles than a conventional battery. It is the recommended option when the car has advanced Start-Stop with regenerative braking (BMW EfficientDynamics, Mercedes Eco, Audi MHEV, Land Rover ECO, Volvo i-Stop). Withstands tilted positions, high vibration and extreme temperatures better than EFB. The Varta A10 is fully original and meets European EN 50342-6 standards for advanced Start-Stop. ### Do I need to register the Varta A10 on the car after installation? On most cars it is not strictly necessary — the alternator detects the new battery and adapts the charge automatically. It is recommended to register the battery via OBD so that the alternator applies the optimal charging profile from the first minute and extends the battery life as much as possible (especially on brands with sophisticated BMS: BMW, Mercedes, Audi, Volvo, Land Rover). Any workshop with an OBD scanner (~10-15 € labour) does it in 5 minutes. DIY apps: VCDS / Carista (VAG), Bimmercode (BMW), iCarsoft. If you do not register, the car will still start correctly — the alternator just takes a few days to adjust the profile. The Varta A10 ships factory-charged at 80-90% so you can use it straight after fitting. ## Compatible vehicles This battery fits 3 vehicles. 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