# Auxiliary battery Fulbat AUX14-J 12V 14Ah AGM

![Auxiliary battery Fulbat AUX14-J 12V 14Ah AGM](https://baterias.com/6488-home_default/battery-fulbat-aux14-j-12v-14ah.jpg)

> Fulbat AUX14-J auxiliary battery 12V 14Ah AGM. Auxiliary AGM range. Dimensions 150×87×145 mm, + terminal on the left. Check fitment by plate.

**Category:** [Auxiliary Batteries](https://baterias.com/gb/auxiliary-batteries) → [FULBAT](https://baterias.com/gb/fulbat)

- **Canonical URL**: https://baterias.com/gb/battery-fulbat-aux14-j-12v-14ah
- **Language**: en-GB
- **Brand**: FULBAT
- **Reference**: BCOM-FULBAT-AUX14-J
- **MPN**: AUX14-J
- **Stock**: Out of stock

## Technical specifications

| Feature | Value |
|---|---|
| Brand | FULBAT |
| Model | FULBAT Auxiliary AGM |
| Voltage (V) | 12 V |
| Largo | 150 mm |
| Ancho | 87 mm |
| Alto | 145 mm |
| Tecnología | AGM |
| Terminal layout | Positive left |
| Capacity (C20) | 14 Ah |
| Capacity (C10) | 12 Ah (c10) |

## Quick description

**Fulbat AUX14-J 12V 14Ah** is an AGM support battery designed for daily cycling while keeping voltage stable for the vehicle systems.

## 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
14 Ah C20

📏 Dimensions
150×87×145 mm

⚙️ Technology
AGM

🧭 Polarity
Positive on the left

🏷️ Model
FULBAT Auxiliary AGM

## Description

## Auxiliary battery Fulbat AUX14-J 14Ah 12V

12*V* Voltage
14*Ah* Capacity

The **12 V**, **14 Ah** **Fulbat AUX14-J** auxiliary battery with AGM technology powers the auxiliary network of cars with advanced Start-Stop and heavy electronics. Its 150 × 87 × 145 mm and the positive terminal on the left make it the exact replacement for the 14 Ah battery fitted as standard to many vehicles with an auxiliary battery.
- Protects the main battery and the alternator.
- AGM: faster recharging and better cycle resistance than a conventional battery.
- Direct replacement for the original auxiliary battery.
- Supports advanced Start-Stop systems.

### What the Fulbat AUX14-J is for

With 14 Ah, the Fulbat AUX14-J is the direct replacement for the original auxiliary battery in the auxiliary network of cars with advanced Start-Stop and heavy electronics.

### Dimensions, polarity and mounting

The Fulbat AUX14-J is made in the 150 × 87 × 145 mm format. The positive terminal on the left decides which side the cables end up on: it is the detail that causes most buying mistakes, so check it before ordering. Before replacing it, measure your current battery tray: if all three dimensions and the terminal positions match, the swap is direct and needs no adapters.

### Why choose Fulbat batteries

French brand Fulbat is a European reference in motorcycle, garden and leisure batteries: compact ranges, clear JIS codes and a consistent quality that workshops know well. All the Fulbat batteries in our catalogue are genuine product, recently manufactured and covered by the manufacturer's warranty.

### Technology inside the Fulbat AUX14-J

Within the Fulbat catalogue, the AUX14-J is the 14 Ah model designed for this application.
AGM (Absorbent Glass Mat) technology seals the electrolyte in glass microfibre. The result is a maintenance-free battery that is highly vibration-resistant and able to withstand deep discharges that would ruin a classic lead-acid battery.

### Care and maintenance

Replace it with the same technology and capacity as the original. Charge with a charger that has an AGM mode: it limits the voltage and protects the glass-fibre separators.

### Official warranty

The Fulbat AUX14-J comes with the **manufacturer's official warranty** against manufacturing defects. If it fails through a defect within the warranty period, we replace it at no cost to you.

### Delivery times and returns

Orders placed **before [[ks:cutoff]]** with the battery in stock ship the same day. Delivery in mainland Spain and Portugal takes 24-48 working hours; for the Balearic Islands and the rest of the European Union allow 3 to 5 working days. You have **[[ks:return_days]] days** to return an unused battery; in mainland Spain and Portugal collection is free. We email you the tracking number as soon as the parcel ships.

## Frequently asked questions

### How do I fit the AUX14-J 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 our blog. 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.

### What is the service life of the AUX14-J model?

Expected lifespan of the Fulbat AUX14-J is 4 to 7 years in regular use (depends on technology and climate). 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 measurements of the AUX14-J model?

Dimensions (length × width × height) are 150×87×145 mm — also written as 150x87x145 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.

### Does this battery fit my car?

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 AUX14-J typically fits a wide range of European vehicles thanks to its standard DIN case format.

### Which batteries are equivalent to the Fulbat AUX14-J?

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.


## Technical team (editorial authorship)

The FAQs, guides and comparisons on this site are reviewed by the baterias.com technical team — automotive battery specialists since 2012.

→ https://baterias.com/gb/technical-team

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*baterias.com — Automotive batteries · 2026-10-22*