Specifications
| Brand | VARTA |
|---|---|
| Part number | AUX9 |
| Voltage (V) | 12 |
| Capacity (C20) | 9Ah (c20) |
| Cold cranking amps (EN) | 130A |
| Technology | Lead-acid |
| Length | 151.00 mm |
| Width | 87.00 mm |
| Height | 106.00 mm |
Varta AUX9 12V 9Ah 130A is an AGM support battery designed for daily cycling while keeping voltage stable for the vehicle systems.
Muy buena atención al teléfonoResuelven tus dudas y te ayudan con la instalaciónMe asesoraron con la elección de la bateria. GraciasReviews originally written in Spanish

The Varta AUX9 car battery is the 12 V, 9 Ah and 130 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. Its 151 × 87 × 106 mm dimensions and positive terminal on the left make it the exact replacement for the 9 Ah battery fitted as standard in many cars.
The Varta AUX9 is compatible with more than 18 vehicles: it is fitted as standard or as a replacement by brands such as Volvo and Mercedes-Benz. It is a benchmark option when you need a battery for Volvo, Mercedes-Benz or other models that use this same format. Not sure whether it is the right one for your car? Check in seconds by entering your registration number in our finder.
The Varta AUX9 is made in the 151 × 87 × 106 mm format and weighs 2,67 kg. The positive terminal on the left 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 B00 hold-down and a Y4 terminal, the system that secures it to the vehicle's battery tray. Before replacing it, measure the space your current battery occupies: if it matches on all three dimensions and on the terminal positions, the swap is direct and needs no adapters.
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.
Varta is an original equipment (OEM) supplier to a good share of Europe's car manufacturers: many cars leave the factory with a Varta fitted. Buying a replacement means, in most cases, refitting the original battery with the same quality and the brand's official warranty.
Varta combines more than a century of experience with Clarios's industrial production: it is the battery many manufacturers choose as standard and one of the most recommended by workshops. Like every lead-acid battery, it is 100% recyclable.
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.
The Varta AUX9 battery comes with the official manufacturer warranty.
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.
Download the official technical sheet for this battery with all the manufacturer data.
Data sheet
Specific References
Reviews originally written in Spanish
Muy buena atención al teléfono
Resuelven tus dudas y te ayudan con la instalación
Me asesoraron con la elección de la bateria. Gracias
Gracias por tan buen servicio, necesitamos mas gente que te atienda asi de bien
| Brand | Varta · see all Varta batteries |
|---|---|
| Manufacturer range | Dynamic AUX (formerly Silver Dynamic Aux) |
| Manufacturer part number (MPN) | AUX9 |
| Also known as | 509106013 · Varta Silver Dynamic Aux AUX9 · Varta Dynamic AUX AUX9 |
| ETN code | 509106013G412 (short form 509 106 013) |
| EAN-13 barcode | 4016987167823 |
| Dimensions (length × width × height) | 151 × 87 × 106 mm (151x87x106) |
The Varta AUX9 is interchangeable with these equivalent references: TK091 (Tudor), EK091 (Exide).
| Product | Specifications | Technology | Price |
|---|---|---|---|
|
|
12V 9Ah 130A | Lead-acid | €59.10 |
|
|
12V 9Ah 120A | AGM | €61.70 |
|
|
12V 9Ah 120A | AGM | €55.40 |
Equivalences verified by our technical team: same dimensions, polarity, capacity and CCA. Official manufacturer warranty on every option.
The Varta AUX9 fits 18 vehicles. Most searched below:
See all 18 compatible vehiclesStep-by-step guide to replace your car battery in 15-30 minutes (longer if the battery is under the seat or in the boot) without losing vehicle settings.
Park on a flat surface, switch off the engine and remove the key. Make sure all lights and electrical accessories are off. Wait 1-2 minutes before starting.
Open the bonnet. The battery is usually in the engine bay, but in many modern cars it may be in the boot or under the passenger seat. Check the manual if you cannot find it.
Use the 10 mm wrench to loosen the negative cable nut (black, marked −) and remove the cable from the post. Move it aside so it cannot touch any bodywork.
Repeat with the positive cable (red, marked +). Important: never let a terminal touch metal of the car while the other is still connected.
Loosen the bottom hold-down clamp with the same wrench. Lift the battery carefully (it can weigh 15-25 kg). Clean the tray with a brush and baking soda if there is corrosion.
Place the battery in the same orientation as the old one (positive terminal on the same side). Tighten the hold-down clamp firmly.
Connect the positive (+) terminal first, then the negative (−). Tighten the nuts with the wrench until each terminal does not move. Apply anti-spark grease if you have any.
Close the bonnet. Start the engine to confirm everything works. On cars with Start-Stop or a BMS, you may need to register the battery via OBD so the alternator applies the correct charging profile.
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.
Expected lifespan of the Varta AUX9 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.
Dimensions (length × width × height) are 151×87×106 mm — also written as 151x87x106 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.
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 AUX9 fits 18 verified vehicle versions in our database.
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.
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