# Kronobat AUX1 · Auxiliary battery 12V 35Ah 520A

![Kronobat AUX1 · Auxiliary battery 12V 35Ah 520A](https://bateriasonline.es/2072-home_default/kronobat-aux1.jpg)

> Kronobat AUX1: 35 Ah auxiliary battery, 520 A (EN), 212×175×140 mm, positive terminal on the right. Equivalent to Varta AUX1. Ask for a no-obligation quote.

**Category:** [Auxiliary batteries (back-up and in-vehicle service)](https://bateriasonline.es/en/auxiliary-backup-batteries) → [Kronobat](https://bateriasonline.es/en/kronobat-batteries)

- **Canonical URL**: https://bateriasonline.es/en/kronobat-aux1
- **Language**: en
- **Brand**: Kronobat
- **Reference**: BOL-KRONOBAT-AUX1
- **MPN**: AUX1
- **Last updated**: 2026-11-06

## Technical specifications

| Feature | Value |
|---|---|
| Brand | Kronobat |
| Range | AUXILIARY |
| Application | Auxiliary and back-up use |
| Technology | Lead-acid |
| Voltage | 12 V |
| Capacity | 35 Ah |
| Cold cranking amps (EN) | 520 A |
| Length | 212 mm |
| Width | 175 mm |
| Height | 140 mm |
| Weight | 10.75 kg |
| Polarity | Positive terminal on the right |

## Quick description

The Kronobat AUX1 is an auxiliary battery with 12 V, 35 Ah and 520 A cold cranking current, measuring 212 × 175 × 140 mm, with the positive terminal on the right.

## Description

## Where the Kronobat AUX1 fits

The Kronobat AUX1 is an auxiliary vehicle battery: it powers back-up functions such as Start-Stop, electric steering or the emergency system while the main battery starts the engine. Without it, Start-Stop or back-up warnings appear on the dashboard.
The AUX1 belongs to the Kronobat AUXILIARY range. [The full range of Kronobat batteries](https://bateriasonline.es/en/kronobat-batteries)

## Equivalents and alternatives to the Kronobat AUX1

Same dimensions and polarity as the AUX1, with similar capacity and cranking power; as a conventional battery, the AUX1 can also be replaced by an EFB or AGM of the same size if you want more cycles.

| Model | Technology | Capacity | Cold cranking (EN) | Dimensions (mm) |
|---|---|---|---|---|
| Varta AUX1 | Lead-acid | 35 Ah | 520 A | 212 × 175 × 140 |

## What it means that the AUX1 is lead-acid

The AUX1 is a conventional lead-acid battery, with plates immersed in liquid electrolyte. Avoid leaving them discharged, as they sulphate, and charge them with a charger that cuts off or switches to maintenance when finished.

## What to look at before buying the AUX1

- The AUX1 needs 212 × 175 × 140 mm of space: measure it with the hold-down clamp in place.
- Polarity of the AUX1: positive terminal on the right (if yours has it on the other side, the cables will not reach).
- Capacity of the AUX1: 35 Ah; the same as your current battery or slightly more is fine.
- The AUX1 delivers 520 A cold cranking (EN standard); do not go below what your original battery states.

## Kronobat AUX1 codes and part numbers

The AUX1 is listed under these codes on labels, in garages and in catalogues:

| Commercial reference | AUX1 |
|---|---|
| Not to be confused with | Kronobat AUX14 (13 Ah, 200 A, positive terminal on the left), Kronobat AUX9 (9 Ah, 130 A, positive terminal on the left) |

## Frequently asked questions about the Kronobat AUX1

### How much does the Kronobat AUX1 weigh?

The AUX1 weighs 10.75 kg.

### Which battery is equivalent to the Kronobat AUX1?

With the same dimensions, polarity and similar capacity you have the Varta AUX1. As the AUX1 is a conventional battery, an EFB or AGM of the same size also works.

### What is the cold cranking current of the Kronobat AUX1?

520 A to the EN standard, with 35 Ah capacity.

### Which side is the positive terminal on the Kronobat AUX1?

The AUX1 has the positive terminal on the right, looking at the battery from its long side with the terminals closest to you.

### What warnings does the car give when the auxiliary battery fails?

Typically Start-Stop unavailable, back-up battery fault or emergency call system fault. The car still starts, but those functions are disabled.

## Keep comparing: alternatives to the AUX1

- [More auxiliary batteries (back-up and in-vehicle service)](https://bateriasonline.es/en/auxiliary-backup-batteries)
- [Full Kronobat catalogue](https://bateriasonline.es/en/kronobat-batteries)
- [Varta AUX1](https://bateriasonline.es/en/varta-aux1) · 35 Ah, 520 A, 212×175×140 mm

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*bateriasonline.es — Batteries and accessories · 2026-11-10*