# Fulbat AUX14 · Auxiliary battery 12V 12.6Ah

![Fulbat AUX14 · Auxiliary battery 12V 12.6Ah](https://bateriasonline.es/589-home_default/fulbat-aux14.jpg)

> Fulbat AUX14: 12.6 Ah auxiliary battery, 150×87×145 mm, positive terminal on the left, AGM. Equivalent to Exide EK131 and Tudor TK131.

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

- **Canonical URL**: https://bateriasonline.es/en/fulbat-aux14
- **Language**: en
- **Brand**: Fulbat
- **Reference**: BOL-FULBAT-AUX14
- **MPN**: AUX14
- **Last updated**: 2026-11-06

## Technical specifications

| Feature | Value |
|---|---|
| Brand | Fulbat |
| Range | FULBAT Auxiliary AGM |
| Application | Auxiliary and back-up use |
| Technology | AGM |
| Voltage | 12 V |
| Capacity | 12.6 Ah |
| Length | 150 mm |
| Width | 87 mm |
| Height | 145 mm |
| Weight | 4.53 kg |
| Polarity | Positive terminal on the left |

## Quick description

Fulbat AUX14: auxiliary battery (AGM) with 12 V and 12.6 Ah, measuring 150 × 87 × 145 mm, with the positive terminal on the left.

## Description

## The Fulbat AUX14 at a glance

The Fulbat AUX14 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 AUX14 belongs to the Fulbat FULBAT Auxiliary AGM range. [The full range of Fulbat batteries](https://bateriasonline.es/en/fulbat-batteries)

## What it means that the AUX14 is AGM

The AUX14 is AGM: the electrolyte is absorbed in glass fibre mats, so it is sealed and spill-proof. It withstands many more cycles than a conventional lead battery, at the cost of being more sensitive to overcharging.

## Fulbat AUX14 vs AUX14-J, AUX12 and AUX9: differences

The real differences between the AUX14 and the closest Fulbat models:

| Model | Capacity | Dimensions (mm) | Positive | Weight |
|---|---|---|---|---|
| Fulbat AUX14 (this one) | 12.6 Ah | 150 × 87 × 145 | left | 4.53 kg |
| Fulbat AUX14-J | 14 Ah | 150 × 87 × 145 | left | 4.62 kg |
| Fulbat AUX12 | 10.5 Ah | 150 × 87 × 130 | left | 4.1 kg |
| Fulbat AUX9 | 8.4 Ah | 150 × 87 × 105 | left | – |

- Fulbat AUX14-J: 1.40 Ah more, the same dimensions.
- Fulbat AUX12: 2.10 Ah less, a different height (130 mm instead of 145 mm). It is the option if your battery tray cannot take the 145 mm height of the AUX14.
- Fulbat AUX9: 4.20 Ah less, a different case (150 × 87 × 105 mm).

## Equivalents and alternatives to the Fulbat AUX14

Other AGM batteries that fit the AUX14's tray with the same polarity: an AGM can only be replaced by another AGM.

| Model | Technology | Capacity | Dimensions (mm) |
|---|---|---|---|
| Varta AUX14 | AGM | 13 Ah | 150 × 87 × 146 |
| Kronobat AUX14 | AGM | 13 Ah | 150 × 87 × 146 |
| Exide EK131 | AGM | 13 Ah | 150 × 90 × 145 |
| Tudor TK131 | AGM | 13 Ah | 150 × 90 × 145 |
| Fulmen FK131 | AGM | 13 Ah | 150 × 90 × 145 |
| Deta DK131 | AGM | 13 Ah | 150 × 90 × 145 |

## Part numbers and codes for the Fulbat AUX14

The AUX14 is listed under these codes on labels, in garages and in catalogues:

| Commercial reference | AUX14 |
|---|---|
| Not to be confused with | Fulbat AUX12 (10.5 Ah), Fulbat AUX14-J (14 Ah) |

## What to look at before buying the AUX14

- Capacity of the AUX14: 12.6 Ah; the same as your current battery or slightly more is fine.
- With the terminals facing you, the positive terminal of the AUX14 is on the left.
- Length, width and height of the AUX14: 150 × 87 × 145 mm.

## Frequently asked questions about the Fulbat AUX14

### AUX14 or AUX14-J: which one suits me?

Compared with the AUX14, the Fulbat AUX14-J has 1.40 Ah more. With 14 Ah, the AUX14-J runs longer between charges than the AUX14 (12.6 Ah). Both measure 150 × 87 × 145 mm, so they fit the same tray.

### Fulbat AUX14 or AUX12: what changes?

Mainly the height: the AUX14 is 145 mm tall and the Fulbat AUX12 130 mm, with the same length and width and 10.5 Ah against 12.6 Ah. Before choosing between the AUX14 and the AUX12, measure the free height of the battery compartment with the cover or bonnet closed.

### How much does the Fulbat AUX14 weigh?

4.53 kg, with 12.6 Ah of capacity. For reference, the Fulbat AUX14-J (14 Ah) weighs 4.62 kg.

### Which battery is equivalent to the Fulbat AUX14?

Only other AGM batteries with its dimensions and polarity: Varta AUX14, Kronobat AUX14 and Exide EK131. Neither an EFB nor a conventional battery replaces the AUX14.

### Which side is the positive terminal on the Fulbat AUX14?

On the AUX14, the positive terminal is on the left with the terminals facing you: compare it with your current battery, because with reversed polarity the cables will not reach.

## More batteries to compare with the AUX14

- [All auxiliary batteries (back-up and in-vehicle service)](https://bateriasonline.es/en/auxiliary-backup-batteries)
- [The whole Fulbat range](https://bateriasonline.es/en/fulbat-batteries)
- [Varta AUX14](https://bateriasonline.es/en/varta-aux14) · 13 Ah, 200 A, 150×87×146 mm
- [Kronobat AUX14](https://bateriasonline.es/en/kronobat-aux14) · 13 Ah, 200 A, 150×87×146 mm

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