# Tudor TK091 · Auxiliary battery 12V 9Ah 120A

![Tudor TK091 · Auxiliary battery 12V 9Ah 120A](https://bateriasonline.es/2446-home_default/tudor-tk091.jpg)

> Tudor TK091: 9 Ah auxiliary battery, 120 A (EN), 150×90×105 mm, positive terminal on the left, AGM. Equivalent to Exide EK091 and Varta AUX9.

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

- **Canonical URL**: https://bateriasonline.es/en/tudor-tk091
- **Language**: en
- **Brand**: Tudor
- **Reference**: BOL-TUDOR-TK091
- **EAN**: 3661024056557
- **MPN**: TK091
- **Price**: 60,27 € (VAT incl., Spain)
- **Last updated**: 2026-11-06

## Technical specifications

| Feature | Value |
|---|---|
| Brand | Tudor |
| Range | TUDOR Start-Stop Auxiliary |
| Application | Auxiliary and back-up use |
| Technology | AGM |
| Voltage | 12 V |
| Capacity | 9 Ah |
| Cold cranking amps (EN) | 120 A |
| Length | 150 mm |
| Width | 90 mm |
| Height | 105 mm |
| Weight | 3.1 kg |
| Polarity | Positive terminal on the left |
| Terminal type | M12 |

## Quick description

Tudor TK091: auxiliary battery (AGM) with 12 V, 9 Ah and 120 A cold cranking current, measuring 150 × 90 × 105 mm, with the positive terminal on the left.

## Description

## Who the Tudor TK091 is for

The Tudor TK091 is the second battery fitted in many modern cars. Without it, Start-Stop or back-up warnings appear on the dashboard.
The TK091 belongs to the Tudor TUDOR Start-Stop Auxiliary range. [More Tudor batteries](https://bateriasonline.es/en/tudor-batteries)

## Equivalents and alternatives to the Tudor TK091

As the TK091 is an AGM battery, we only list other AGM batteries with its dimensions and polarity: neither an EFB nor a conventional battery can replace it.

| Model | Technology | Capacity | Cold cranking (EN) | Dimensions (mm) |
|---|---|---|---|---|
| Exide EK091 | AGM | 9 Ah | 120 A | 150 × 90 × 105 |
| Fulmen FK091 | AGM | 9 Ah | 120 A | 150 × 90 × 105 |
| Deta DK091 | AGM | 9 Ah | 120 A | 150 × 90 × 105 |
| Varta AUX9 | AGM | 9 Ah | 130 A | 151 × 87 × 106 |
| Kronobat AUX9 | AGM | 9 Ah | 130 A | 151 × 87 × 106 |
| Fulbat AUX9 | AGM | 8.4 Ah | – | 150 × 87 × 105 |

## Tudor TK091 vs TK111

The real differences between the TK091 and the closest Tudor models:

| Model | Capacity | Cold cranking (EN) | Dimensions (mm) | Positive | Weight |
|---|---|---|---|---|---|
| Tudor TK091 (this one) | 9 Ah | 120 A | 150 × 90 × 105 | left | 3.1 kg |
| Tudor TK111 | 11 Ah | 150 A | 150 × 90 × 130 | left | 3.9 kg |

- Tudor TK111: 2 Ah more, 30 A more cranking power, a different case (150 × 90 × 130 mm).

## Inside the TK091: AGM technology

Inside, the TK091 has glass fibre separators (AGM) that hold the electrolyte. The TK091 needs a charger with an AGM mode that does not exceed 14.7 V.

## Check this before ordering the Tudor TK091

- Length, width and height of the TK091: 150 × 90 × 105 mm.
- With the terminals facing you, the positive terminal of the TK091 is on the left.
- Your current battery should say about 9 Ah; a little more is also fine.
- Check the EN amps on your battery: if it says 120 A or less, the TK091 covers your engine.

## Tudor TK091 codes and part numbers

This is how the Tudor TK091 appears on the label and in parts catalogues:

| Commercial reference | TK091 |
|---|---|
| EAN | 3661024056557 |
| Terminal type | M12 |

## Frequently asked questions about the Tudor TK091

### Tudor TK091 or TK111?

Compared with the TK091, the Tudor TK111 has 2 Ah more and 30 A more cranking power. If your current battery says 150 A or more, choose the TK111; if it says 120 A or less, the TK091 is enough. Mind the space: the TK111 measures 150 × 90 × 130 mm.

### How much does the Tudor TK091 weigh?

The TK091 weighs 3.1 kg. For reference, the Tudor TK111 (11 Ah) weighs 3.9 kg.

### Which battery is equivalent to the Tudor TK091?

Only other AGM batteries with its dimensions and polarity: Exide EK091, Fulmen FK091 and Deta DK091. Neither an EFB nor a conventional battery replaces the TK091.

### Which side is the positive terminal on the Tudor TK091?

The TK091 has the positive terminal on the left, 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.

## More batteries to compare with the TK091

- [More auxiliary batteries (back-up and in-vehicle service)](https://bateriasonline.es/en/auxiliary-backup-batteries)
- [More Tudor models](https://bateriasonline.es/en/tudor-batteries)
- [Exide EK091](https://bateriasonline.es/en/exide-ek091) · 9 Ah, 120 A, 150×90×105 mm
- [Fulmen FK091](https://bateriasonline.es/en/fulmen-fk091) · 9 Ah, 120 A, 150×90×105 mm

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